EXPT.1. EFFECT OF LEGUME INTERCROP AND CONVENTIONAL METHODS OF WEED SUPPRESSION ON TUBER YIELD OF POTATO

M. SALIM AND M. K. ALAM

Abstract

An experiment was conducted at the Tuber Crops Research Sub-Centre, Munshiganj during 2021-22 with seven treatments namely T₁ = Control (No weeding), T₂ = Weeding with spade and hilling up (2 times) at 30 and 60 DAP, T₃ = Herbicide + Weeding with spade and hilling up (2 times) at 30 and 60 DAP, T₄ = Sowing mug, T₅ = Sowing Khesari, T₆ =  Sowing chick pea and T₇ =  Sowing pea with a view to select suitable weed control methods for quality potato production as well as improvement of soil health. Results showed that the best performance to suppress weed i.e. the lowest (0.062gm) fresh biomass of weed accumulation was recorded from T₇ treatment which was followed by T₆ and T₅ treatment. The maximum potato equivalent yield (36.90 t/ha), gross return (Tk. 442800/ha), net return (Tk.254800/ha) and benefit cost ratio (2.35) were found in T₆ treatment which was followed by T₇ and T₅ treatment. Therefore, considering the fresh biomass of weed accumulation, yield and yield contributing characters, legumes intercrop with potato like khesari, chick pea and pea may be practiced to cultivate potato in our country to get maximum profit.

e

Introduction

Weed control is an important factor determining the profitability of potato, as well as any other crop production, since among all plant pests, weeds result in the highest reduction in potential yield (Fernandez-Quintanilla et al., 2008). Tuber crop losses in potato cultivation caused by weed infestation are estimated at 20-80% (Jaiswal and Lal, 1996; Hashim, 2003). The effect of weed infestation on crops plants yield depends on the abundance and biomass of weeds and their species composition. The studies by Andreasen et al. (2006) shows that the amount of macro elements taken up weeds may be similar, or even higher, than the amounts absorbed by cultivated plants. Control of weed infestation in potato is usually carried out using mechanical and chemical treatments. Despite the use of herbicides to effectively control a broad spectrum of weeds for more than seventy years, new problems have arisen. These include for example the occurrence of new weed species and biotypes resistant to herbicides in the crops (Heap, 2015). Activities aimed at sustainable development favor the introduction of alternative methods of weed control. One of them is cultivation of ground-cover plants, including living mulches, that have an ability to suppress weeds and positively affect arrange of soil properties (Hartwig and Ammon, 2002). Living mulches grow in association with the crop and can compete with it for light, water and nutrients, like weeds, which results in yield reduction (Jędrszczyk and Poniedziałek, 2007). It seems, however, to be generally possible to obtain similar or even higher crop yields are possible with such systems than in conventional cultivation (Adamczewska-Sowińska et al., 2009).  In areas where excess nitrogen is already a problem, the use of ground covers may provide a sink to tie up some of this excess nitrogen and hold it until the next growing season, when a crop that can make use of it might be planted (Hooda et al. 1998). Even legumes tend to use soil nitrogen rather than fixing their own, if it is available. It is these possibilities that provide the incentive for looking at the effect of various kinds of cover crops on soil erosion, nitrogen budgets, weed control, and other pest management and environmental problems. The aim of this study to select suitable mulching strategy for quality potato production as well as improve soil health. So, the present study was undertaken with the following objective.To select suitable weed control method for quality potato production as well as improvement of soil health.

Materials and methods

The experiment was conducted at the Tuber Crops Research Sub-Centre, Munshiganj during rabi season of 2021-22. The experiment was executed with seven treatments namely M₁ = Control (No weeding), M₂= Weeding with spade and hilling up (2 times) at 30 and 60 DAP, M₃ = Herbicide + Weeding with spade and hilling up (2 times) at 30 and 60 DAP, M₄ = Sowing mug, M₅ = Sowing Khesari, M₆ = Sowing chick pea and M₇ = Sowing pea with a view to select suitableweed control methods for quality potato production as well as improvement of soil health. BARI Alu-57 was used as test crop. The experiment was laid out in a randomized complete block design (RCBD) with three replications. The Experiment was set on the 18^th December, 2021 maintaining 3.0m X 3.0m plot. Cowdung was applied (10t/ha) during final land preparation. Fertilizers were applied @ 260 kg Urea, 220 kg TSP, 260 kg MP, 120 kg Gypsum, 14kg ZnSO₄, and 6 kg Boric Acid per hectare. Half of Urea and full dose of other fertilizers were applied immediately before planting the seed in furrows and mixed properly with the soil. The rest amount of Urea was side dressed at 35 days after planting. Hamencozeb and Secure were sprayed to control diseases and Admire was sprayed at regular interval of 10 days to prevent insects like aphid and jassids. At the time of final land preparation eco-furan was applied to the soil against cut worm and other soil pests. Legumes crops were harvested first at 95 DAP than final harvesting of potato was done on the 22 March, 2021. Data were taken on Plant height at 60 DAP, Number of stem per hill at 60 DAP, Foliage coverage (%) at 60 DAP, Plant vigor (1-10) Scale at 60 DAP, Fresh biomass of weeds (gm/m²) at 60 DAP, Tuber Grade (% by number) & (% by weight) at final harvest, Tuber fresh yield ton per hectare (t/ha) at 95 DAP, Legumes crops final yield (t/ha) and Cost Benefit ratio. Field Data were analyzed statistically and means were separated by using LSD through Statistix 10 statistical computer program.

Results and Discussion

The results obtained from the experiment are presented and discussed character wise:

There was significant variation was found among the treatments in plant height (cm), number of stem/hill, foliage coverage (%),plant vigor (1-10 scale),  fresh biomass of weed  (gm/m²) at 60 DAP and  tuber yield (t/ha) and legume crops yield (kg/ha) at 95 DAP (Table 1).

Plant height at 60 DAP

At 60 DAP; the highest plant height (77.00 cm) was recorded in T₇, which was statistically at par with T₆, and similar to T₅, T₄ and T₃ whereas the lowest plant height was observed in T₁ (control) treatment.

Number of stem/hill at 60 DAP

The treatment T₇ produced the maximum (6.33) number of stem per hill at 60 DAP which was at par with T₆ whereas the minimum number of stem per hill was recorded in T_1.

Foliage coverage (%) at 60 DAP

The maximum foliage coverage (96.67%) was found in T₇ followed by T₆ and T₅ whereas the lowest foliage coverage (76.67%) was found from the treatment T₁.

Plant vigor at 60 DAP (1-10 scale)

The maximum plant vigor (9.00) was observed in T₇ treatment which was followed by T₆ and T₅ whereas the minimum plant vigor was noted in T₁.

Fresh biomass of weed (gm/m²) at 60 DAP

At 60 DAP, the highest fresh biomass (1.556gm) of weed at 60 DAP was produced by T₁ treatment whereas the minimum fresh biomass (0.0626gm) of weed was found from T₇ treatment which was at par with T₆and T₅ treatment.

Tuber yield at 95 DAP (t/ha)

The potato tuber yield was significantly influenced by the treatments. The maximum potato tuber yield (32.44 t/ha) was found in T₇ which was at par with T₆ whereas the minimum potato tuber yield (18.83 t/ha) was found in T₁ (control).The minimum potato tuber yield was recorded from T₁ treatment it might be the cause of the plants had to compete with weed as it was control treatment i.e. there was no weeding in case treatment T₁. For this reason the weed of T₁ treatment gained maximum fresh biomass (1.556gm) per m².

Legume crops yield at 95 DAP

The legume yield was significantly influenced by the treatments. The maximum legume yield (713 Kg/ha) was found in T₆ which was statistically similar with par with T₇ whereas the minimum potato tuber yield (467gm/ha) was found in T₅ treatment. There was no legume crop yield at 95 DAP in case T₄ i.e. yield of mug was zero.

Table 1. Effect of legume intercrop and conventional methods of weed suppression on plant height, no. of stem/hill, foliage coverage (%), plant vigor, fresh biomass of weed, tuber yield, final legume yield

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

*= Significant at 5% level of probability,                                                                                                                         

T₁= Control, T₂= Hand weeding, T₃= Hervicide+Hand weeding, T₄= Sowing mug, T₅= Sowing khesari, T₆= Sowing Chick pea and T₇= Sowing pea.

Tuber grade (% by number) at 95 DAP

There was significant variation was found for all the treatments in the tuber grade (<28mm, 28-40mm, 40-55mm and >55mm) (Table 2).

T₁ treatmentproduced the highest (26.90%) smaller sized tuber like <28mm which was statistically similar to T_4, T₃ and T₂ whereas the lowest smaller sized tuber was found from T₅ (7.11%) which was statistically similar to T₆ and T₇ (Table 2).

The maximum (51.54%) tuber grade 28-40mm was produced by T7 treatment which was at par with   T₅ and T3whereas the minimum (32.72%) tuber grade 28-40mm was produced by T₂.

The highest (42.60%) tuber grade 40-55mm was found from treatment T2 which was followed by followed by T₃ treatment while the lowest tuber grade 40-55mm (28.33%) was found from T₁ which was statistically at par with T3, T6 and T7.

In case large sized tuber >55mm, the maximum (12.05%) was produced by T₆ whereas the lowest (1.11%) was produced by T4(Table 2).

Tuber grade (% by weight) at 95 DAP

The variation due to effect of treatment for all the tuber grade (<28mm, 28-40mm, 40-55m and >55mm) was found significant (Table 2).

The maximum (6.31%) smaller sized tuber grade <28mm was produced by T4 treatment which was statistically similar with T3whereas the minimum (1.27%) tuber grade <28mm was produced by T₅.

T₁ treatmentproduced the highest (47.86%) tuber grade like 28-40mm which was statistically similar to T₄ whereas the lowest (22.40%) tuber grade 28-40mm was found from T₂ which was statistically similar to T₆ (Table 2).

The highest (55.97%) tuber grade 40-55mm was found from treatment T2 which was at par with T_3, T₄ and T₆ treatment while the lowest tuber grade 40-55mm (28.33%) was found from T₁ which was statistically at par with T₃, T₆ and T₇.

In case large sized tuber >55mm, the maximum (30.02%) was produced by T₆ whereas the lowest (1.11%) was produced by T₄ (Table 2).

Table 2. Effect legume intercrop and conventional methods of weed suppression on tuber grade <28mm, 28-

40mm, 40-55mm and >55mm (% by number) and (% by weight) at 95 DAP

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT *= Significant at 5% level of probability,                                                                                                                         

T₁= Control, T₂= Hand weeding, T₃= Hervicide+Hand weeding, T₄= Sowing mug, T₅= Sowing khesari, T₆= Sowing Chick pea and T₇= Sowing pea

Economic analysis

Productivity of potato and legumes intercropping system with conventional methods of weed suppressionwas evaluated on the basis of equivalent yield.  All the intercropped combinations showed the higher potato equivalent yield over the sole potato except T₄ (Table 2). Among the intercrop treatments, the highest potato equivalent yield (36.90 t/ha) was recorded in T₆ and the lowest equivalent yield (23.65 t/ha) was noted in T₄ where legume crop mug was intercropped with potato in which final yield was zero duo to late planting of mug. Legume intercropping showed higher gross return than sole cropping. Although higher cost of production was involved in sole cropping system like T2 and T3 treatment, highest gross return (Tk. 442800/ha) and net return (Tk.254800/ha) were found in T₆ treatment. Moreover, the treatment T₆ contributed to the highest benefit cost ratio (2.35) which was followed by T7 treatment (Gross return (Tk. 430440/ha) and Net return (Tk.242440/ha and BCR-2.29). The lowest gross return (Tk. 225960/ha), net return (Tk. 38960/ha and BCR-1.21) were found in T₁ treatment (Control). The results revealed that potato grown as intercrop with legumes is more profitable than the sole potato production.

Table 3. Cost of potato cultivation per hectare

Table 4. Price of product

Table 5. Cost and return analysis of potato- legumes intercropping system during 2021-22

PEY= Potato Equivalent Yield

BCR= Benefit Cost Ratio

Conclusion

Considering suppression of weed i.e. the fresh biomass accumulation of weed, yield and yield contributing characters, legumes intercrop with potato like khesari, chick pea and pea may be practiced to cultivate potato in our country to get maximum profit.

References

Adamczewska-Sowińska, K., Kołota, E., Winiarska, S., 2009. Living mulches in field cultivation of vegetables. Veg. Crops Res. Bull. 70, 19-29.

Andreasen, C., Litz, A.S., Strebig, J.C., 2006. Growth response of six weed species and spring barley (Hordeumvulgare) to increasing levels of nitrogen and phosphorus. Crop Sci. 46, 503-512.

Hartwig, N.L., Ammon, H.U., 2002. Cover crops and living mulches. Weed Science 50: 688-699.

Hashim, S., 2003.Chemical weed control efficiency in potato (Solanumtuberosum L.) under agro-climatic conditions of Peshawar, Pakistan. Pak. J. Weed Sci. Res. 9, 105-110.

Heap, I., 2015.The international survey of herbicide resistant weeds. 28 Jan. 2015.www.weedscience.org

Hooda, P. S., Moynagh, N., Svoboda, I. F., and Anderson, H. A. 1998. A comparitive study of nitrate leaching form intensively managed monoculture grass and grass-clover pastures. J. Agric. Sci.131:267–275.CrossRefGoogle Scholar

Jaiswal, V.P., Lal, S.S., 1996. Efficacy of cultural and chemical weed control methods in potato (Solanumtuberosum). Indian J. Agron. 41, 454-456.

EXPT.3. EFFECT OF SPACING AND MULCHING ON WEED INFESTATION AND YIELD OF POTATO

M. SALIM AND M. K. ALAM

Abstract

An experiment was conducted at the Tuber Crops Research Sub-Centre, Munshiganj during 2021-22 with three types of mulch materials namely M₁ = Rice Straw, M₂= Water Hyacinth, M₃= Rice Straw + Water Hyacinth including M₀ = Control (No mulching) with three spacing like S₁ = 75 cm x 30 cm, S₂ = 60 cm x 25 cm and S₃ = 40 cm x 20 cm with a view to identify suitable mulch materials for potato production and find out the effect of spacing and mulching on yield of potato. Results showed that the best performance (39.72 t/ha) was obtained from treatment combination M₃S₂ i.e. M₃ = Rice Straw + Water Hyacinth with S₂ = 60 cm x 25 cm spacing. Therefore, considering the yield and yield contributing characters, mulch materials like mixtures of Rice Straw and Water Hyacinth with 60 cm x 25 cm spacing may be practiced to cultivate potato in our country to get maximum quality yield.

e

Introduction

Mulching, which has become more popular lately, is an important way of soil protection in the plant production. Surface mulching is one of the most cost effective means (Shelton et al., 1995), because of a range of positive effects on the soil fertility and other factors important for plant production. Besides, mulching massively reduces soil erosion (Döring et al., 2005), virus vector in seed potatoes (Döring et al., 2006) and it may also act as a tool for the control of nitrogen losses by immobilization of post-harvest nitrate (Döring et al., 2005). According to Boyd and Acker (2003) the fluctuation of soil moisture, especially in upper soil layers, influences negatively seed germination and emergence. On the other hand, a sufficient layer of mulch can inhibit weeds emergence, as documented by results of some authors who showed a positive effect of mulching on weed density (Johnson et al., 2004; Sinkevičiene et al., 2009). For that reason mulching can be considered as an important weed control factor (Balalis et al., 2002; Radics and Bognar, 2004). Except weeds, insects and fungal diseases are the primary causes of yield loss. The farmers of Munshiganj region use different types of mulch materials like Rice Straw, Water Hyacinth etc with closure spacing. The aim of this study is to evaluate the effect of different mulch materials with spacing on the yield and quality of tubers as well as weed suppression. Information regarding this aspect is scarce in Bangladesh. So, the present study was undertaken with the following objectives.

To identify suitable mulch materials for potato production.

To find out the suitable combination of spacing and mulching on the yield of potato

Materials and methods

The experiment was conducted at the Tuber Crops Research Sub-Centre, Munshiganj during rabi season of 2021-22. The experiment was executed with four types of mulch materials namely M₁ = Rice Straw, M₂= Water Hyacinth, M₃= Rice Straw + Water Hyacinth and M₀ = Control (No mulching) with three spacing like S₁ = 75 cm x 30 cm, S₂ = 60 cm x 25 cm and S₃ = 40 cm x 20 cm with a view to identify suitable mulch materials for potato production and find out the effect of spacing and mulching on yield of potato.  Thus, the number of total treatment is 12 and was laid out in a factorial randomized complete block design with three replications. The Experiment was set on the22^ndDecember, 2021 maintaining 6.0m X 3.0m plot. Cowdung was applied (10t/ha) during final land preparation. Fertilizers were applied @ 260 kg Urea, 220 kg TSP, 260 kg MP, 120 kg Gypsum, 14kg ZnSO₄, and 6 kg Boric Acid per hectare. Half of Urea and full dose of other fertilizers were applied immediately before planting the seed in furrows and mixed properly with the soil. The rest amount of Urea was side dressed at 35 days after planting. Hamencozeb and Secure were sprayed to control diseases and Admire was sprayed at regular interval of 10 days to prevent insects like aphid and jassids. At the time of final land preparation chumbok was applied to the soil against cut worm and other soil pests. Haulm pulling was done after 88 days of planting and final harvesting was done on the 26^th March, 2022. Data were taken on Days to start of emergence, Emergence (%) at 30 DAP, No. of weed per square meter at 60 DAP, Fresh weight of weed (gm/m²) at 60 DAP, Dry weight of weed (gm/m²) at 60 DAP, tuber grade <28mm, 28-40mm, 40-55mm and >55mm (% by number and weight) at 95 DAP, Yield (t/ha) at 95 DAP, and Dry matter percentage at 95 DAP. Field Data were analyzed statistically and means were separated by using LSD through Statistix 10 statistical computer program.

Results and Discussion

The results obtained from the experiment are presented and discussed character wise:

The yield contributing characters at 30 DAP (days after plating)

Days to start of emergence

The effect of interaction between spacing and mulching on days to start of emergence was significant (Table 1). Days to start of emergence was earlier in treatment combination M₃S₂ (11.67 days) which was followed by M₃S₁ and M₃S₃, respectively that was later in M₀S₁.

Emergence percentage at 30 DAP

There was significant interaction effect between spacing and mulching was observed in emergence percentage at 30 DAP. The maximum emergence percentage (97.92%) was produced by treatment combination M₃S₁which statistically similar to M₂S₁ and M₁S₁ and the minimum emergence percentage (81.93%) was observed in M₀S₃.

Number of weed (no./m²) at 30 DAP

The interaction effect between spacing and mulching on number of weed (no./m²) at 30 DAP was significant (Table 1). At 30 DAP the highest number of weed (no./m²) 667.33 was found in M₀S₁ treatment combination which was followed by M₀S₂ and M₀S_3. The lowest number of weed (no./m²) 61.33 was observed in treatment combination M₂S₃ which was at par with M₃S_3. 

Fresh wt. of weed (gm/m²) at 30 DAP

The fresh weight of weed (gm/m²) at 30 DAP was varied significantly by interaction effect between spacing and mulching Table 1. The maximum (1566gm) fresh weight of weed (gm/m²) at 30 DAP was noticed in treatment combination M₀S₁ whereas the minimum (50 gm) fresh weight of weed (gm/m²) was observed in treatment combination M₂S₁ which was statistically at par with all other treatment combination except M₀S_1, M₀S₂ and M₀S_3.

Dry wt. of weed (gm/m²) at 30 DAP

The dry weight of weed (gm/m²) at 30 DAP was varied significantly by interaction effect between spacing and mulching Table 1. The maximum (181gm) dry weight of weed (gm/m²) at 30 DAP was noticed in treatment combination M₀S₁ whereas the minimum (13.62gm) dry weight of weed (gm/m²) at 30 DAP was observed in treatment combination M₃S₃ which was statistically similar with all other treatment combination except M₀S_1, M₀S₂ and M₀S_3.

Table 1. Interaction effect of spacing and mulching on days to start of emergence, emergence (%) of potato plant, number of weed per square meter, fresh and dry weight of weed

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

*= Significant at 5% level of probability,                                                                                                                         

S₁= 75cm x 30 cm, S_\2= 60cm x 25 cm and S₁= 40cm x 20 cm

M₁= Straw, M₂= Water Hyacinth and M₃= Straw+ Water Hyacinth and M₀= Control (No mulching)

The yield contributing characters at 60 DAP

Number of weed (no./m²) at 60 DAP

The interaction effect between spacing and mulching on number of weed (no./m²) at 60 DAP was significant (Table 1). At 60 DAP the highest number of weed (no./m²) 885 was found in M₀S₁ treatment combination which was followed by M₀S₂ and M₀S_3. The lowest number of weed (no./m²) 52.67 was observed in treatment combination M₃S₃ which was statistically similar with  M₃S_1, M₃S₃ and M₂S₃

Fresh wt. of weed (gm/m²) at 60 DAP

The fresh weight of weed (gm/m²) at 60 DAP was varied significantly by interaction effect between spacing and mulching Table 1. The maximum (2060gm) fresh weight of weed (gm/m²) at 60 DAP was noticed in treatment combination M₀S₁ whereas the minimum (53.3 gm) fresh weight of weed (gm/m²) was observed in treatment combination M₃S₃ which was statistically at par with all other treatment combination except M₀S_1, M₀S₂ and M₀S_3.

Dry wt. of weed (gm/m²) at 60 DAP

The dry weight of weed (gm/m²) at 60 DAP was varied significantly by interaction effect between spacing and mulching Table 1. The maximum (197gm) dry weight of weed (gm/m²) at 60 DAP was noticed in treatment combination M₀S₁ whereas the minimum (11.33gm) dry weight of weed (gm/m²) at 60 DAP was observed in treatment combination M₃S₃ which was statistically similar with all other treatment combination except M₀S_1, M₀S₂ and M₀S_3.

The yield contributing characters at 95 DAP

Tuber grade (% by number) at 95 DAP

The interaction effect of spacing and mulching gave significant variation in the tuber grade (<28mm, 28-40mm, 40-55m and >55mm) (Table 2).

The treatment combination M₁S₃ produced the highest (32.92%) smaller sized tuber like <28mm which was statistically similar to M₂S₃ (20.21%) whereas the lowest smaller sized tuber was found from M₃S₁ (9.10%) which was statistically similar to M₃S_1, M₁S₁ and M₃S_3. 

The maximum (59.10%) tuber grade 28-40mm was produced by treatment combination M₃S₃ which was statistically at par with M₃S₂ and M₀S₃ whereas the minimum (31.05%) tuber grade 28-40mm was produced by M₂S₁which was statistically similar with treatment combination M₂S₂.

The treatment combination M₂S₁ produced the highest (44.17%) tuber grade 40-55mm which was followed by M₀S_2, M₁S₁and M₀S₂ while the lowest tuber grade 40-55mm (24.25%) was found from M₃S₂ which was statistically similar to M₃S₃.

In case large sized tuber >55mm, the maximum (10.80%) was produced by M₁S₁ which was statistically similar to M₂S₁ and M₃S₁ whereas the lowest (1.87%) was produced by M₁S₃ which was statistically similar to M₂S₃.

Tuber grade (% by weight) at 95 DAP

The variation due to effect of interaction between spacing and mulching for tuber grade (<28mm, 28-40mm, 40-55m and >55mm) was found significant (Table 2).

The treatment combination M₃S₃ produced the highest (6.05%) smaller sized tuber like <28mm which was statistically at par with M₁S₃ treatment combination whereas the lowest (1.56%) smaller sized tuber was found from M₃S₁ which was statistically similar to M₀S_2.

The maximum (42.65%) tuber grade 28-40mm was produced by treatment combination M₁S₃ which was statistically at par with M₃S₂ and M₃S₃ whereas the minimum (13.27%) tuber grade 28-40mm was produced by M₂S₁ which was statistically similar to treatment combination M₂S₂ and M₁S₁.

The treatment combination M₂S₂ produced the highest (58.15%) tuber grade 40-55mm which was statistically similar to combination M₂S₂ M₂S_1, M₀S₂ and M₂S₃ while the lowest tuber grade 40-55mm (34.93%) was found from M₃S₂ which was statistically similar to M₃S₁.

In case large sized tuber >55mm, the maximum (36.95%) was produced by M₃S₁ which was statistically similar to M₁S₁ whereas the lowest (6.24%) was produced by M₃S₃ which was statistically similar to M₂S₃.

Table 2. Interaction effect of spacing and mulching on tuber grade <28mm, 28-40mm, 40-55mm and >55mm (% by number) at 95 DAP

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

*= Significant at 5% level of probability,                                                                                                                         

S₁= 75cm x 30 cm, S_\2= 60cm x 25 cm and S₁= 40cm x 20 cm

M₁= Straw, M₂= Water Hyacinth and M₃= Straw+ Water Hyacinth and M₀= Control (No mulching)

Table 3. Interaction effect of spacing and mulching on yield (t/ha) and dry matter percentage at 95 DAP

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

*= Significant at 5% level of probability,                                                                                                                         

S₁= 75cm x 30 cm, S_\2= 60cm x 25 cm and S₁= 40cm x 20 cm

M₁= Straw, M₂= Water Hyacinth and M₃= Straw+ Water Hyacinth and M₀= Control (No mulching)

Tuber fresh yield (t/ha) at 95 DAP

Significant variation was observed due to interaction effect of spacing and mulching for tuber fresh yield (t/ha) (Table 3).

The highest (39.72t/ha) tuber fresh yield was obtained from M₃S₂ treatment combination which was statistically dissimilar to treatment combination M₃S_3, M₂S₂ and M₂S₃ whereas the lowest (26.57t/ha) tuber fresh yield was produced by M₀S₁ which was followed by M₁S₁ and M₀S_2, M₀S_1, M₃S_3, and M₂S₃ (Table 3).

Tuber dry matter (%) at 95 DAP

The variation due to effect of spacing and mulching for tuber dry matter percentage was found significant (Table 3). 

The maximum (20.84%) tuber dry matter percentage was recorded from treatment combination M₃S₁ which was followed by treatment combination M₁S₁ and M₂S₂ whereas the lowest (18.40%) dry matter was produced by M₂S₃ (Table 3)

Conclusion

Considering the yield and yield contributing characters, mulch materials like mixtures of rice straw and water hyacinth with 60 cm x 25 cm spacing may be practiced to cultivate potato in our country to get maximum quality yield.

References

Balalis, D., Sidiras, N., Economou, G., Vakali, C., 2002. Effect of different levels of wheat straw soil          surface coverage on weed flora in Viciafabacrops.J.Agron. Crop Sci., 189: 233-241.

Boyd, N., van Acker, R., 2003. The effects of depth and fluctuating soil moisture on the emergence of        eight annual and six perennial plant species. Weed Sci., 51: 725-730.

Döring, T., Brandt, M., Heß, J., Finckh, M.R., Saucke, H., 2005. Effects of straw mulch on soil nitrate dynamics, weeds, yield and soil erosion in organically grown potatoes. Field Crops Res., 94: 238-249.

Döring, T., Heimbach, U., Thierne, T., Finckh, M., Saucke, H., 2006. Aspect of straw mulching in organic potatoes –I. Effect on microclimate, Phytophora infestans, and Rhizoctonia solani. Nachrichtenbl. Deut. Pflanzenschutzd, 58: 73-78.

Johnson, J.M., Hough-Goldstein, J.A., Vangessel, M.J., 2004. Effect of straw mulch on pest insects,            predators and weeds in watermelons and potatoes. Environ. Entomol., 33: 1632-1643.

Radics, L., Bognar, E.S., 2004. Comparison of different methods of weed control in organic green bean      and tomato. Acta Hort. (ISHS), 638: 189-196.

Shelton, D.P., Dickey, S.D., Hachman, S.D., Steven, S., Fairbanks, K.D., 1995. Corn residue cover on soil surface after planting for various tillage and planting systems.J. Soil and Water Conser., 50: 399-404.

Sinkevičiene, A., Jodaugiene, D., Pupaliene, R., Urboniene, M., 2009. The influence of organic mulches on soil properties and crop yield. Agronomy Research, 7 (Special issue I): 485-491.

EXPT.4. DRY MATTER PARTITIONING AND YIELD OF PROCESSING OF POTATO VARIETIES

M. SALIM AND M. K. ALAM

Abstract

An experiment was conducted at Tuber Crops Research Sub-Center, Bangladesh Agricultural Institute, Munshiganj, during 2021–22 to evaluate three processing potato varieties for growth pattern, dry matter partitioning to the sink and yield performance of processing potato varieties at different days after planting (DAP). The dry matter content was measured at five different harvest. The results revealed that BARI Alu-25 was the highest producer of fresh tuber yield, followed by BARI Alu-28 which was significantly different from BARI Alu-29. From the results, the BARI Alu-25 had effectively allocated the DM to the tuber relative to others, which is the ultimate goal of potato crop production. The slow-growing nature and its efficiency of partitioning DM to its tubers made BARI Alu-25 a high yielder with appropriate tuber characteristics. Moreover, BARI Alu-29 was found to be an early variety, performing all the growth activities and DM accumulation in a short period of time, compared with the remaining varieties. From this, it can be concluded that BARI Alu-25 appeared to be the highest yielder, followed by BARI Alu-28 and BARI Alu-29 was found as a early yielder.

Introduction

Potato (Solanum tuberosum) is the second largest food crop in Bangladesh next to rice and has recently occupied an important place in the list of major food and cash crops of Bangladesh (Ali and Haque, 2011). The area and production of potatoes are increasing day by day due to its higher demand and profitability. Potato is grown more or less in all the districts of Bangladesh, but produced better in the districts of Munsiganj, Bogra, Rangpur, Dinajpur and some parts of greater Cumilla (Anon., 2014). In the last few decades, several dozens of high yielding varieties (HYV) of potato were brought to Bangladesh and tried experimentally under local conditions before they were recommended for commercial cultivation (Khalil et al., 2013). Finally, about 91 high yielding varieties (HYVs) have been released for cultivation in our country by the Tuber Crop Research Center of BARI of which Diamant, Cardinal, Granola, Asterix, Lady Rosetta, Courage, Binnela, Multa, Provento, Heera, Dheera, etc. are remarkable. Some of these varieties are late or some are early or medium late or medium early (Haque et al., 1993). Moreover, these varieties differ in various growth characters that largely influence the growing pattern, intercultural operations, and yield of a particular variety. Research on potato cultivars is usually limited to analyzing differences in tuber yield, but has rarely done such analyses that account for the origins of such differences. Indeed, potato cultivars show considerable diversity in terms of growth rates due to their genetic make-up and their interaction with the environment. Therefore, a study of growth performance and dry matter partitioning in the various plant organs during development is important to determine a cultivar’s growth rate and production. Therefore, detailed and organized growth analysis of processing varieties particularly dry matter partitioning may be useful towards achieving high yield and finally, popularization of varieties to the farmers. But a little or no work has been done on growth analysis of processing varieties in our climatic condition. Considering the above facts, the present study is undertaken to analyze the growth performance and dry matter partitioning in different organs of three processing potato varieties at different days after planting.

Materials and methods

The experiment was conducted at the research field of the Tuber Crops Research Sub-Center, Bangladesh Agricultural Research Institute, Munshiganj, during the potato growing season of 2021–22. The experiment was laid out in a randomized complete block design with three replications. Apparently, disease free, uniform sized (28–55mm) well sprouted whole tubers of three processing potato varieties viz. BARI Alu-25, BARI Alu-28 and BARI Alu-29 were planted on 17^thDecember 2021 following a spacing of 60cm×25cm. The unit plot size was 4.8m×3.0m. Urea, TSP, MoP, gypsum, zinc sulphate and boric acid were applied @ 265, 220, 280, 85, 14 and 12 kg/ha, respectively. Besides, cow-dung was applied @ 10 t/ha during final land preparation. Full dose of TSP, MP, gypsum, zinc sulphate, boric acid and half of urea were applied in furrows at the time of planting of tubers and then mixed in soil so that the tubers did not come in contact with fertilizers. The remaining half of urea was applied as top dressing at 30days after planting (DAP). Irrigation, weeding, earthing up and other intercultural operations were done as and when necessary to raise a good crop. Eco-furan at the rate of 15 kg/ha was applied during the final land preparation to control ant, mite, cutworm, aphid and other soil borne insects. Admire (0.2%) was sprayed in three installments at 45, 60and 70 DAP to control insects. The crops were sprayed with Cleanzeb, Dithane-M 45 (0.2%) alternatively five times (at 30, 40, 50, 60 and 70DAP) to prevent late blight infection and other disease of potato. Final harvest was done on 26 March, 2022. For estimation of dry matter partitioning, single plant was harvested from each plot randomly at, 60, 70, 80, 90 and 100 days after planting (DAP) excluding the plants in the outer rows. Total plant biomass was separated into leaves, stems, roots and tubers. Therefore, fresh weight of each biomass group was taken with an electric balance and made sun dried to discharge water and after that all parts were kept in an electric oven. The temperature of the oven was set to 65°C and was dried for at least 48h or up to a constant weight. The final weight of the dried sample was taken by an electric balance. For estimating the proportion of total dry matter or assimilate per plant partitioned to different parts (leaf, stem, root and tuber) of the plant, following formulae was used.

Proportion of leaf /stem /root /tuber dry weight (%) =

          Leaf/stem/root/tuber dry weight(g)  ×100

Total dry weight (leaf+stem+tuber+root) per plant (g)

The collected data on various parameters were statistically analyzed using Statistix 10 program. The means were separated by Duncan’s Multiple Range Test (DMRT) at 1 or 5% level of probability.

Results and discussion

Data on dry matter partitioning of different plant organs viz. stem, leaf, root, tuber and total dry matter per plant (g) was determined during the five consecutive harvests (60, 70, 80, 90 and 100 DAP) and are presented in (Tables1–6). At first harvest (Table 1), at 60 DAP, variation in the percentage of dry matter partitioning to stem, leaf, root, tuber and total dry matter accumulation was observed significant. The highest (25.33%) proportion of assimilates in stem was observed in BARI Alu-25 which was at par with  BARI Alu-28 while the lowest (7.06%) in BARI Alu-29. Similar trend of dry matter partitioning variation was observed in case leaf and root. For tuber, the highest fraction of assimilates was diverted to tubers in case of BARI Alu-29 (64.98%) while the lowest (25.33%) was found from BARI Alu-29. At this harvest date, the total dry weight per plant was significantly different where the highest value was found in BARI Alu-28 (196 gm) and lowest (138 gm) in BARI Alu-25. At 60 DAP, tuber contributed higher fraction of total assimilates produced per plant for all the three processing varieties. It may be due to all the varieties were at active tuber bulking stage at 60 DAP. Potato cultivars differed greatly in the proportion of dry matter allocation to different plant parts (tuber, leaf, stem, and root) over time opined by Geremew et al (2007).

Table1.Dry Matter Partitioning of Different Parts and Total Dry Weight Per Plant of Three Processing Potato

Varieties at 60DAP

In a Column, Means Followed by Same Letter(s) are not Statistically Different by DMRT.

At harvesting after 70 days of planting (Table 2), the highest (27.02%) proportion of dry matter partitioned to stems was found in the variety BARI Alu-29, followed by BARI Alu-28 (21.36%) and the lowest (18.79%) proportion was observed in BARI Alu-25 variety. The percentage of dry matter partitioned to leaf, root, tuber and total dry weight per plant varied significantly among the cultivars. The highest (32.35%) proportion of dry matter in the leaf was found in BARI Alu-28 and the lowest (10.57%) was observed in BARI Alu-29. The maximum (59.92%) proportion of dry matter in the tuber and the highest (216 gm) total dry weight per plant was found in BARI Alu-29. Tubers had contributed the highest fraction of assimilates during this harvest date (70 DAP) for all cultivars and the roots contributed the minimum share of assimilates, followed by stems. Geremew et al (2007) found varietal differences in dry matter allocation to different plant parts of different potato varieties.

Table 2. Dry Matter Partitioning of Different Parts and Total Dry Weight Per Plant of Three Processing Potato

Varieties at 70 DAP.

In a Column, Means Followed by Same Letter(s) are not Statistically Different by DMRT.

There was no significant variation among the varieties was found during the third harvest (at 80 DAP) for stem, root and total dry weight per plant but dry matter accumulation in leaf and tuber was varied significantly where BARI Alu-29 got its highest (226 gm) total DM accumulation and had the highest (75.86%) DM translocation towards tuber and the least towards root (Table 3). At this harvest date, the highest (22.05%) DM accumulation in the stem was observed for BARI Alu-25, compared with BARI Alu-28, which had the least (17.86%) accumulation. During this growth period, the proportion of DM translocated to leaf was higher (25.%) for BARI Alu-29 and the least (11.09%) for BARI Alu-29. BARI Alu-29 had the highest (226 gm) total DM accumulation and it was the lowest (187 gm) for BARI Alu-25. Tubers had accumulated the highest proportion of assimilates during this time for all varieties.

Table 3. Dry Matter Partitioning of Different Parts and Total Dry Weight Per Plant of Three Processing Potato

Varieties at 80 DAP

In a Column, Means Followed by Same Letter(s) are not Statistically Different by DMRT.

At the fourth harvest (90 DAP), percentage of stem, leaf, root, tuber and the total DM accumulation differed significantly among varieties (Table 4). At 90 DAP; BARI Alu-25 had the highest (84.05%) proportion of DM translocated to tubers whereas the least (67.34%) was observed in BARI Alu-28. BARI Alu-25 had the highest (239 gm) total DM accumulation and it was the lowest (181 gm) for ARI Alu-28.

Table 4.Dry Matter Partitioning of Different Parts and Total Dry Weight Per Plant of Three Processing Potato

Varieties at 90 DAP

In a Column, Means Followed by Same Letter(s) are not Statistically Different by DMRT.

During the fifth and final harvest (100 DAP), all the varieties were already at the stage of senescing where BARI Alu-29 had completely senesced (Table 5). In general, DM partitioning to different plant parts was uniformly consistent among varieties for all the parameters considered. Translocation of assimilates was lower for leaves, stems and roots whereas the highest for tubers. At final harvest, BARI Alu-25 had the highest (88.48%) proportion of DM translocated to tubers whereas BARI Alu-28 obtained the least (76.10%) tubers dry matter allocation. BARI Alu-25 had the highest (241 gm) total DM accumulation and the lowest (188 gm) was observed in BARI Alu-28.

During final harvest, the tuber fresh yield (t/ha) varied non-significantly for all the varieties. The maximum (26.78 t/ha) fresh tuber yield was found from BARI Alu-25 whereas the minimum (21.47 t/ha) was obtained from BARI Alu-29 (Table 6).

These findings are in agreement with the results of Spitters (1987), who concluded that potato cultivars differed greatly in the proportion of DM allocation to the tuber over time. Spitters (1987) grouped potato cultivars into three categories for the growth, development, and DM allocation to the tuber. One group was those cultivars in which tuber filling started early and harvest index increased rapidly with time and after the onset of tuber filling, assimilates were largely used for tuber growth. The second group was those cultivars in which tuber filling also started early, but harvest index increased less rapidly with time and a substantial fraction of current assimilates partitioned to the haulm growth. The third group was those cultivars in which tuber filling started later and showed a gradual increase of harvest index, with a continuous diversion of a major fraction of current assimilates to the production of new leaves and stem growth.

Table 5. Dry Matter Partitioning of Different Parts and Total Dry Weight Per Plant of Three Processing Potato

Varieties at 100 DAP

In a Column, Means Followed by Same Letter(s) are not Statistically Different by DMRT.

Table 6. Tuber fresh yield of Three Processing Potato Varieties at 100 DAP (Final Harvest)

In a Column, Means Followed by Same Letter(s) are not Statistically Different by DMRT.

Conclusion

Three potato cultivars were compared for their final yield, DM production and partitioning to the different plant parts, including the tubers. The main factor determining DM production was the length of the growth period. The results revealed that all varieties performed differently at different harvests. In addition, BARI Alu-29 was found to be an early variety, performing all the growth activities and DM accumulation in a short period of time, compared with the remaining varieties. Such a growth character, however, is not favorable for high tuber yield, since DM partitioning to tuber requires prolonged vegetative growth and high DM allocation efficiency, which is genotype-specific. The earliness of BARI Alu-29 could be advantageous under rain fed agriculture, where the rainfall duration is limited, but not under adequate irrigation where maximum yield is expected. Another advantage is that the earlier production enables processing factories to open their season earlier and get better use of their capital investment. This research finding reveals, however, that BARI Alu-25 was the highest producer of fresh tuber yield, followed by BARI Alu-28 which was significantly different from BARI Alu-29. From the results, the BARI Alu-25 had effectively allocated the DM to the tuber relative to others, which is the ultimate goal of potato crop production. The slow-growing nature and its efficiency of partitioning DM to its tubers made BARI Alu-25 a high yielder with appropriate tuber characteristics. Hence, this newly developed potato cultivar is very suitable for the intended commercial production in Bangladesh.

References

Ali MS, Haque MA. 2011. Potato for Food Security in SAARC Countries.SAARC, Seed Congress and Fair 2011, Dhaka, Bangladesh.

Anonymous. Estimates of Potato, 2012–2013. Agriculture Wing, Bangladesh Bureau of Statistics, Government of the People’s Republic of Bangladesh, Agargaon, Dhaka-1207. 2014.

Geremew EB, Steyn JM, Annandale J G. 2007. Evaluation of Growth Performance and Dry Matter Partitioning of Four Processing Potato (Solanumtuberosum.L.) Cultivars. New Zealand J Crop Hort Sci.; 35(3): 385–393p.

Haque MA, Miah MAM, Hossain S, et al. 2012. Profitability of BARI Released Potato(Solanum tuberosum L.) Varieties in Some Selected Locations of Bangladesh. Bangladesh J Agric Res.; 37(1): 149–158p.

Khalil MI, Haque ME, Hoque MZ. 2013. Adoption of BARI Recommended Potato (Solanum tuberosum L.) Varieties by the Potato Farmers of Bangladesh. The  Agriculturists.; 11(2): 79–86p.

Spitters CJT 1987. An analysis of variation in yield among potato cultivars in terms of light absorption, light utilization and dry matter partitioning. Potato Agro meteorology, Acta Horticulture 214:71-

EXPT.5. PRODUCTIVITY AND PROFITABILITY STUDY OF FARMERS MANAGED AND RESEARCH MANAGED POTATO PRODUCTION SYSTEM

M. SALIM AND M. K. ALAM

Abstract

An experiment was conducted at the Tuber Crops Research Sub-Centre,Munshiganj during 2021-22 with two varieties namely V₁= BARI Alu =37  and V₂= BARI Alu-25 with two management practices namely P₁= Research practice and P₂= Farmers' Practice with a view to compare the yields between the farmers' practice and research practice and find out the better economic output of potato production system. Results showed that considering the tuber fresh yield, tuber dry matter percentage, insect and diseases reaction and economic analysis the best performance was obtained from treatment combination V₂P₁ andnV₁P₁.

Introduction

Potato (Solanumtuberosum L.) is one of the most important vegetable crops and extensively grown in Munshigonj region. But the farmers prefer to use a different production system rather than recommended practice by research organization. Farmers are used to use imported seed and have to buy a box of 50 (Fifty) kg seed potato at minimum 5000/- (Five thousand taka). They plant cut tuber with densely maintaining spacing in addition to high dosages of fertilizer application. On the contrary, TCRC recommends whole tuber potato seed maintaining more spacing and less use of fertilizer. But farmers are not interested to adopt this (TCRC) generated practice due to assumed low economic returns. That's why the present study is undertaken with the above mentioned objectives.

Materials and methods

The experiment was conducted at the Tuber Crops Research Sub-Centre, Munshiganj during rabi season of 2021-2022. The experiment was executed with two varieties namely V₁= BARI Alu=37 and V₂= BARI Alu-25 with two management practices namely P₁= Research practice and P₂= Farmers' Practice. Thus, the number of total treatment is 4 and was laid out in a randomized complete block design (RCBD) (factorial experiment) with three replications. The Experiment was set on the 20^th December, 2021 maintaining 4.8m X 3.0m plot with 60cm x 25cm spacing (TCRC Practice) and 40cm x 15cm (Farmers' Practice). In case TCRC Practice, Cowdung was applied (10t/ha) during final land preparation. Fertilizers were applied @ 350 kg Urea, 220 kg TSP, 260 kg MP, 120 kg Gypsum, 14kg ZnSO₄, and 6 kg Boric Acid per hectare. Half of Urea and full dose of other fertilizers were applied immediately before planting the seed in furrows and mixed properly with the soil. The rest amount of Urea was side dressed at 35 days after planting. Weeding, earthing up, 2-3 times flood irrigation at 30 DAP, 45 DAP and 60 DAP and other intercultural operations were done as and when necessary for raising a good crop. Hamencozeb and Secure were sprayed to control diseases and Admire was sprayed at regular interval of 10 days to prevent insects like aphid and jassids. At the time of final land preparation Furadan 5G / Chlorophyriphos 25EC was applied to the soil against cut worm and other soil pests. Haulm pulling was done after 85 days of planting. On the other hand in case Farmers' Practice, Fertilizers were applied @ 700 kg Urea, 440 kg TSP, 520 kg MP, 240 kg Gypsum per hectare. Seed tuber was imported from foreign countries. At the time of final land preparation Furadan 5G / Chlorophyriphos 25EC was applied to the soil against cut worm and other soil pests. No earthing up was done. Fungicides were used 6 times at 7 days interval but insecticides were used single time. Weeding and sprinkler irrigation with irrigation pipe were done as and when necessary. Final harvesting was done on the 29^th February, 2020. Data were taken on Days to start of emergence,Emergence (%) at 30 DAP, Plant height at 45 & 60 DAP, Number of stem per hill at 45 & 60 DAP, Foliage coverage (%) at 45 & 60 DAP, Plant vigor (1-10) Scale at 60 DAP, Tuber Grade (% by number) and (% by weight), Tuber number per plant at 95 DAP, Average of tuber size at 95 DAP, Tuber fresh weight per plant (g) at 95 DAP , Tuber fresh yield ton per hectare (t/ha) at 95 DAP, Tuber dry matter (%) at 95 DAP, No. and yield of marketable and non-marketable tuber at 95 DAP; and, Cost Benefit ratio. Field Data were analyzed statistically and means were separated by using LSD through Statistix 10 statistical computer program.

Results and Discussion

The results obtained from the experiment are presented and discussed character wise:

Days to start of emergence:

Interaction effect of variety and management practice on days to start of emergence was non-significant (Table 1). Days to start of emergence was earlier in treatment combination V₁P₁ (14.67 days) and whereas later in V₂P₂.

Emergence (%) at 30 DAP:

Interaction effect of variety and management practice on emergence (%) at 30 DAP was significant (Table 1). The highest (94.44%) emergence was found from treatment combination V₂P₁ which was followed byV₁P₁ treatment combination whereas the lowest (71.42%) value was provided by V₁P₂.

Plant height at 45 and 60 DAP

Plant height at 45 and 60 DAP varied non-significantly due to interaction effect of variety and management practice (Table 1). At 45 DAP; the maximum (76.67cm) plant height was obtained from treatment combination V₂P₁ whereas the minimum(57.19cm) plant was found fromV₁P_2.  Similar trend of plant height was observed at 60 DAP (Table 1).

Number of stem per hill at 45 and 60 DAP: 

Variation due to interaction effect of variety and management practice on number of stem per hill at 45 and 60 DAP was significant (Table 1). At 45 DAP; the maximum (4.39) number per hill was observed from V₁P₁ whereas the minimum (2.38) value was found from V₂P₂. At 60 DAP; variation was same pattern as 45 DAP.

Foliage coverage at 45 and 60 DAP:

Foliage coverage at 45 and 60 DAP varied non-significantly due to interaction effect of variety and management practice (Table 1). At 45 DAP; the maximum (83.10%) foliage coverage was obtained from treatment combination V₁P₁ whereas the minimum(76.49) plant was found fromV₁P_2. But at 60 DAP; the maximum (89.13%) foliage coverage was obtained from treatment combination V₂P₁ whereas the minimum(79.92) plant was found fromV₁P₂ (Table 1).

Plant vigor at 45and 60 DAP:

Variation due to interaction effect of variety and management practice on plant vigor at 45 and 60 DAP was non-significant (Table 1). At 45 and 60 DAP; the maximum (8.67 and 8.67) vigorus plant number was observed from V₂P₁; respectivelywhereas the minimum (6.67) value was found from V₂P₂ at 45 and 60 DAP; respectively (Table 1).

Table 1. Interaction effect of variety and management practice on days to start of emergence, emergence % at 30

DAP, plant height, number of stem per hill foliage coverage, plant vigor of potato

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

**= Significant at 1% level of probability, *= Significant at 5% level of probability                                                                                                                  

V₁= BARI Alu-37, V₂=BARI Alu-25

Tuber grade (% by number) at 95 DAP

The interaction effect of variety and management practice gave non-significant variation in the tuber grade (<28mm and 40-55m) but significant variation was found from tuber grade 28-40mm (Table 2). The treatment combination V₁P₁ produced the highest (51.70%) tuber grade 28-40mm which was statistically similar to V₂P₁ (44.46) and V₂P₂ (43.58%) whereas the lowest (37.47%) tuber grade 28-40 mm was found from V₁P₂  (Table 2).

Tuber grade (% by weight) at 95 DAP

The interaction effect of variety and management practice gave significant variation in the tuber grade (28-40mm, 40-55m and >55mm) but variation was found non-significant from tuber grade <28mm (Table 2). The treatment combination V₂P₂ produced the highest (51.81%) tuber grade 28-40mm which was statistically at par with V₂P₁ (48.04) whereas the lowest (23.79%) tuber grade 28-40 mm was found from V₁P₂  followed by V₁P₁ (Table 2). In case tuber grade 40-55mm; the maximum (41.16%) was observed in treatment combination V₁P₁ which was at par with V₁P₂ whereas the lowest value was produced by treatment combination V₂P₂ (Table 2).  The same pattern of variation was observed in case of larger size tuber (Table 2).

Table 2. Interaction effect of management practice on tuber grade <28mm, 28-40mm, 40-55mm and >55mm (%

by number) at 95 DAP of potato

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

**= Significant at 1% level of probability, *= Significant at 5% level of probability                                                                                                                 

V₁= BARI Alu-37, V₂=BARI Alu-25

Tuber fresh yield (t/ha) at 95 DAP:

Interaction effect of variety and management practice on tuber fresh yield (t/ha) at 95 DAP was found significant. The maximum tuber fresh yield (30.84 t/ha) was produced by treatment combination V₁P₁ which was statistically similar to V₂P₁ and V₁P₂ whereas the minimum (20.83 t/ha) tuber fresh yield was found from V₂P₁ (Table 3).

Tuber dry matter (%) at 95 DAP:

Interaction effect of variety and management practice on tuber dry matter percentages at 95 DAP was found non-significant. The maximum (20.83%) tuber dry matter was obtained from treatment combination V₂P₁ whereas the minimum (17.18%) tuber dry matter  was found from V₁P₂ (Table 3).

Cutworm Infestation (%) at 95 DAP:

Interaction effect of variety and management practice on cut worm infestation percentage at 95 DAP was found significant. The maximum (14.82%) cut worm infestation was found from treatment combination V₁P₂ which was statistically similar to treatmentcombinationV₂P₂ whereas the minimum (4.57%) was found from V₁P₁ (Table 3).

Common Scab infection (%) at 95 DAP:

Interaction effect of variety and management practice on common scab infection percentage at 95 DAP was found insignificant. The maximum (25.38%) common scab infection was found from treatment combination V₁P₂ whereas the minimum (6.04%) was found from V₂P₁ (Table 3).

Table 3. Interaction effect of managements on tuber fresh yield and dry matter percentage at 95 DAP

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

**= Significant at 1% level of probability, *= Significant at 5% level of probability                                                                                                                 

V₁= BARI Alu-37, V₂=BARI Alu-25

Economic analysis

Treatment combination V₁P₁ showed the highest gross return (Tk. 370080/ha) and net return (Tk. 163080/ha) and Benefit Cost Ratio (BCR)-1.79 which was followed by treatment V₂P_1. (Tk.349860/ha) and net return (Tk. 142860/ha) and Benefit Cost Ratio (BCR)-1.45. The lowest gross return (Tk. 276000 /ha), net return (Tk. 25700/ha and BCR-1.10) were found in treatment combination V₁P₂ (Control). The results revealed that potato grown with research management is more profitable than the farmer’s practices.

Table 4. Cost of potato cultivation per hectare

Table 5. Price of product

Table 6. Cost and return analysis of mulching and plant spacing on weed control and yield of sweet potato  system during 2021-22

BCR= Benefit Cost Ratio

Conclusion

From the above discussion it may be concluded that the treatment combination (V₁P₁) and (V₂P₁) performed better in terms of tuber fresh yield, tuber dry matter percentage, insect and diseases reaction and economic anal

EXPT.6. EFFECT OF DIFFERENT TYPES OF MULCHING AND PLANT SPACING ON WEED CONTROL AND YIELD OF SWEET POTATO AT MUNSHIGANJ REGION

M. SALIM AND M. K. ALAM

Abstract

An experiment was conducted at the Tuber Crops Research Sub-Centre, Munshiganj during 2021-22 with four types of mulch materials namely M₁ = Rice Straw, M₂= Water Hyacinth, M₃= Rice Straw + Water Hyacinth including M₀ = Control (No mulching) with three spacing like S₁ = 75 cm x 50 cm, S₂ = 60 cm x 30 cm and S₃ = 50 cm x 20 cm with a view to findout the suitable combination of mulching and plant spacing on weed control and yield of sweet potato in Munshiganj region. Results showed that treatment combination M₂S₂ performed better to control weed than control plot (no mulching). In case yield, the maximum root yield (39.81 t/ha) was obtained from treatment combination M₂S₂ which was at par with M₃S₂. Therefore, considering the weed suppression, yield and yield contributing characters, mulch materials like M₂ = water hyacinth with S₂=60 cm x 30 cm spacing may be practiced to cultivate sweet potato in our country to get maximum quality yield.

e

Introduction

Mulching, which has become more popular lately, is an important way of soil protection in the plant production. Surface mulching is one of the most cost effective means (Shelton et al., 1995), because of a range of positive effects on the soil fertility and other factors important for plant production. According to Boyd and Acker (2003) the fluctuation of soil moisture, especially in upper soil layers, influences negatively seed germination and emergence. On the other hand, a sufficient layer of mulch can inhibit weeds emergence, as documented by results of some authors who showed a positive effect of mulching on weed density (Johnson et al., 2004; Sinkevičiene et al., 2009). For that reason mulching can be considered as an important weed control factor (Balalis et al., 2002; Radics and Bognar, 2004). Except weeds, insects and fungal diseases are the primary causes of yield loss. Weed management is a critical, costly and a major constraint to successful sweet potato production since weeds compete with the crop for nutrients, water and sunlight causing losses as high as 50–60% (Stall, 2010). Weed control in sweet potato production is difficult because of the vine like growth habit of sweet potato, and the availability of only a few registered herbicides for this crop and evidence of herbicide injury in certain cultivars (Seem et al., 2003). Aldrich reported in general for crops that plant spacing can affect weed growth and its ability to compete with the crop (Aldrich, 1987). Integrated weed management (IWM) approach such as mechanical, cultural and use of herbicides for crops grown on large acreages is needed to effectively control weeds during early stages of growth when competition is high to enhance production (Mwanda, 2000). The objective of the present study is to determine the effectiveness of different types of mulching, narrow plant spacing and other control measures on weed control and yield of sweet potato in Munshiganj region.

Materials and methods

The experiment was conducted at the Tuber Crops Research Sub-Centre, Munshiganj during rabi season of 2021-21. The experiment was executed with four types of mulch materials namely M₁ = Rice Straw, M₂= Water Hyacinth, M₃= Rice Straw + Water Hyacinth and M₀ = Control (No mulching) with three spacing like S₁ = 75 cm x 50 cm, S₂ = 60 cm x 30 cm and S₃ = 50 cm x 20 cm with a view to identify suitable mulch materials for sweet potato production and find out the effect of spacing and mulching on quality yield of sweet potato.  Thus, the number of total treatment is 12 and was laid out in a randomized complete block design (RCBD) (Factorial design) with three replications. The Experiment was set on the 28^thOctober, 2021 maintaining 3.0m X 3.0m plot. Cowdung was applied (10t/ha) during final land preparation. Fertilizers were applied @ 265 kg Urea, 155 kg TSP, 245 kg MP, 700 kg Gypsum, 10 kg ZnSO₄, and 6 kg Boric Acid per hectare. Half of Urea and MP, full dose of other fertilizers were applied immediately before planting the seed in furrows and mixed properly with the soil. The rest amount of Urea and MP was side dressed at 35 days after planting.Final harvesting was done on the 25^th February, 2022. Data were taken on, Number of weed (no./m²) at 30 & 60 DAP, Fresh wt. of weed (gm/m²) at 30 & 60 DAP, Dry wt. of weed (gm/m²) at 30 & 60 DAP, Size Classes of Roots at final harvest, Yield of  root tuber at final harvest; and Cost Benefit ratio. Field Data were analyzed statistically and means were separated by using LSD through Statistix 10 statistical computer program.

Results and Discussion

The results obtained from the experiment are presented and discussed character wise:

Number of weed (no. /m²) at 30 DAP

The interaction effect of different types of mulching and plant spacingon number of weed (no./m²) at 30 DAP was significant (Table 1). At 30 DAP the highest number of weed (no./m²) 825.00 was found in M₀S₁ treatment combination which was statistically similar with M₀S₂ and statistically dissimilar to all other treatment combination. The lowest number of weed (31.00) per square meter was observed in treatment combination M₃S₃ which was followed byM₁S₃ and M₃S_2, respectively.

Fresh wt. of weed (gm/m²) at 30 DAP

The fresh weight of weed (gm/m²) at 30 DAP was significantly varied by interaction of different types of mulching and plant spacing (Table 1). The maximum (1641.7gm) fresh weight of weed (gm/m²) at 30 DAP was noticed in treatment combination M₀S₁ which was statistically at par with treatment combination M₀S₂. The minimum (42.7gm) fresh weight of weed (gm/m²) at 30 DAP was observed in treatment combination M₃S₃which was statically similar with all other treatment combination exceptM₀S_1, M₀S₂ and M₀S₃.

Dry wt. of weed (gm/m²) at 30 DAP

The variation was found significant in case dry weight of weed (gm/m²) at 30 DAP by interaction effect of different types of mulching and plant spacing (Table 1). The maximum (166.93gm) dry weight of weed (gm/m²) at 30 DAP was noticed in treatment combination M₀S₁ which was statistically dissimilar to all other treatment combination.  The minimum (11.02gm) dry weight of weed (gm/m²) at 30 DAP was observed in treatment combination M₂S₃ which was statistically similar with all other treatment combination except M₀S_1, M₀S₂ and M₀S_2.

Number of weed (no. /m²) at 60 DAP

The interaction effect of different types of mulching and plant spacingon number of weed (no./m²) at 60 DAP was significant (Table 1). At 60 DAP the highest number of weed (no./m²) (691.33) was found in M₀S₁ treatment combination which was statistically dissimilar to all other treatment combination. The lowest number of weed (22.00) per square meter was observed in treatment combination M₃S₃ which was statistically at par with M₁S_3, M₂S₃ and M₃S_2, respectively.

Fresh wt. of weed (gm/m²) at 60 DAP

The fresh weight of weed (gm/m²) at 60 DAP was significantly varied by interaction of different types of mulching and plant spacing (Table 1). The maximum (1530.00gm) fresh weight of weed (gm/m²) at 60 DAP was noticed in treatment combination M₀S₁ which was statistically dissimilar with all other treatment combination. The minimum (22.00gm) fresh weight of weed (gm/m²) at 60 DAP was observed in treatment combination M₂S₃which was statically similar with all other treatment combination except M₀S_1, M₀S₂ and M₀S₃.

Dry wt. of weed (gm/m²) at 60 DAP

The variation was found significant in case dry weight of weed (gm/m²) at 60 DAP by interaction effect of different types of mulching and plant spacing (Table 1). The maximum (160.28gm) dry weight of weed (gm/m²) at 60 DAP was noticed in treatment combination M₀S₁ which was statistically dissimilar to all other treatment combination.  The minimum (5.00gm) dry weight of weed (gm/m²) at 60 DAP was observed in treatment combination M₂S₃ which was statistically at par with M₃S₃.

Table 1. Effect of spacing and mulching on number of weed per square meter, fresh weight and dry weight of weed at 30 DAP and 60 DAP

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

*= Significant at 5% level of probability,                                                                                                                         

S₁= 75cm x 50 cm, S_\2= 60cm x 30 cm and S₁= 50cm x 20 cm

M₁= Straw, M₂= Water Hyacinth and M₃= Straw+ Water Hyacinth and M₀= Control (No mulching)

Size Classes of Roots (% by number) at 120 DAP

The interaction effect of different types of spacing and mulching, gave significant variation in the size classes of roots (small, medium, large and extra-large) (Table 2).

The treatment combination M₂S₃ produced the highest (72.64%) small size roots whereas the lowest (36.14%) small size tuber was found from M₁S₂ which was statistically at par with M₂S₁ and M₃S_2. 

The maximum (38.86%) medium size root was produced by treatment combination M₁S₂ which was statistically at par with M₃S₂ and M₁S₁ whereas the minimum (16.53%) medium size root was produced by M₂S₃ which was statistically similar to treatment combination M₃S₃ and M₀S₁.

The treatment combination M₂S₁ produced the highest (22.03%) large size roots which were at par with  M₁S_2, M₂S₂ and M₀S₂ while the lowest large size roots (5.26%) was found from M₃S₃ which was statistically similar to M₁S₃, M₂S₃ and M₃S_1.

In case extra-large size roots, the maximum (11.44%) was produced by M₀S₁ which was statistically similar to M₂S₁whereas the lowest (1.66%) was produced by M₁S₃ which was statistically similar to M₃S₃.

Tuber grade (% by weight) at 120 DAP

The interaction effect of different types of spacing and mulching, gave significant variation in the size classes of roots (small, medium, large and extra-large) (Table 2).

The treatment combination M₃S₃ produced the highest (33.97%) small size roots (% by weight) which were statistically similar with treatment combination M₁S₃ andM₂S₃ whereas the lowest (11.69%) small size tuber was found from M₁S₂ which was statistically at par with M₁S_1, M₂S₂ and M₂S_1. 

The maximum (39.79%) medium size root was produced by treatment combination M₃S₂ which was statistically at par with M₁S₂ whereas the minimum (20.67%) medium size root was produced by M₀S₁ which was statistically similar to treatment combination M₀S₂.

The treatment combination M₁S₂ produced the highest (35.21%) large size roots which were followed by   M₀S_2, M₂S₂ and M₃S₁ while the lowest large size roots (17.21%) was found from M₁S₁ which was statistically similar to M₂S₃

In case extra-large size roots, the maximum (38.36%) was produced by M₀S₁ whereas the lowest (10.30%) was produced by M₁S₃ which was statistically similar to M₁S₂.

Table 2. Effect of spacing and mulching on Size Classes of Roots (Small, Medium, Large and Extra-large) (% by

number) and (% by weight) at 120 DAP

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

*= Significant at 5% level of probability,                                                                                                                         

S₁= 75cm x 50 cm, S_\2= 60cm x 30 cm and S₁= 50cm x 20 cm

M₁= Straw, M₂= Water Hyacinth and M₃= Straw+ Water Hyacinth and M₀= Control (No mulching)

Tuber fresh yield (t/ha) at 120 DAP

Significant variation was observed due to interaction effect of different types of spacing and mulching for root fresh yield (t/ha) (Table 2).

The highest (39.81 t/ha) root fresh yield was obtained from treatment combination M₂S₂ which was statistically at par with treatment combination M₃S₂ whereas the lowest (24.80 t/ha) root fresh yield was produced by M₀S₁ which was statistically similar to M₀S_3, M₁S_1, M₀S_2, and M₀S₃ (Table 2).

Economic analysis

Treatment combination M₂S₂ showed the highest gross return (Tk.398100/ha) and gross margin (Tk. 235100/ha) and Benefit Cost Ratio (BCR)-2.44 which was followed by treatment combination M₃S_2. The lowest gross return (Tk. 248000/ha), gross margin (Tk. 65000/ha and BCR-1.35) were found in treatment combination M₀S₁ (Control). The results revealed that potato grown with mulch materials like dried water hyacinth with spacing 60cm x 30cm  is more profitable than the other practices.

Table 3. Cost of sweet potato cultivation per hectare

Table 4. Price of product

Table 5. Cost and return analysis of mulching and plant spacing on weed control and yield of sweet potato during 2021-22

BCR= Benefit Cost Ratio

Conclusion

Considering the yield and yield contributing characters, mulch materials like M₂ = water hyacinth with S₂=60 cm x 30 cm spacing may be practiced to cultivate sweet potato in our country to get maximum yield.

References

Aldrich RJ. Predicting crop yield reductions from weeds. Weed Technology. 1987;1: 199-206.

Balalis, D., Sidiras, N., Economou, G., Vakali, C., 2002. Effect of different levels of wheat straw soil surface coverage on weed flora in Viciafabacrops.J.Agron. Crop Sci., 189: 233-241.

Boyd, N., van Acker, R., 2003. The effects of depth and fluctuating soil moisture on the emergence of eight annual and six perennial plant species. Weed Sci., 51: 725-730.

Mwanda, C. O., 2000. A note on weed control in Machakos District, Kenya. http:/www.atnesa.org.

Radics, L., Bognar, E.S., 2004. Comparison of different methods of weed control in organic green bean and tomato.Acta Hort. (ISHS), 638: 189-196.

Seem JE, Creamer NG, Monks DW. Critical weed free period for ‘Beauregard’ sweet potato (Ipomoea batatas]. Weed Technology. 2003;17:686-695.

Shelton, D.P., Dickey, S.D., Hachman, S.D., Steven, S., Fairbanks, K.D., 1995. Corn residue cover on soil surface after planting for various tillage and planting systems.J. Soil and Water Conser., 50: 399-404.

EXPT.7.EFFECT OF INTEGRATED FERTILIZER MANAGEMENT ON PRODUCTIVITY AND PROFITABILITY OF ORGANIC POTATO PRODUCTION

M. SALIM, M. K. ALAM AND S. PARVIN

Abstract

An experiment was conducted to select safe and profitable potato production system through application of bio-fertilizers under organic management practices. The experiment was executed at the organic block under TCRC research field, Joydebpur during the year of 2021-22. Two bio-fertilizers namely Azotobacter and Phosphorus Soloblizing Bacteria (PSB) which dosage were each one 8 ml per kg seed potato in liquid form and three organic fertilizers with different dosages name 10 ton/ha and 8 ton/ha were chosen as the treatment. The number treatment was 8 namely T₁ : Control, T₂ : Vermicompost 10 t/ha, T₃ : Trico-compost 10 t/ha, T₄ : ACI Organic Fertilizer 10 t/ha, T₅ : Bio-fertilizer (Azotobacter + PSB), T₆ :  Vermicompost 8 t/ha + (Azotobacter + PSB), T₇ :  Trico-compost 8 t/ha + (Azotobacter + PSB, T₈ :  ACI Organic Fertilizer 8 t/ha + (Azotobacter + PSB). BARI Alu -25 was used as material produced under organic production system at organic block, TCRC, Gazipur following organic practices. The result showed that The maximum (18.27 t/ha) tuber yield was obtained from T₈ treatment which was treated with (ACI Organic Fertilizer 8 t/ha) + (Azotobacter + PSB)  was at par with T₆ and T₇ treatment whereas the minimum fresh tuber yield was produced by treatment T₁ (control). Moreover, the highest gross return (Tk. 657720/ha) and net return (Tk. 128720/ha) and Benefit Cost Ratio (BCR)-1.24 found from T8 treatment which was followed by T₆ treatment_. (Tk. 610920/ha) and net return (Tk. 81920/ha) and Benefit Cost Ratio (BCR)-1.15 and T₄ treatment (Tk. 582120/ha) and net return (Tk. 77120/ha) and Benefit Cost Ratio (BCR)-1.15, respectively.

Introduction

             Potato (Solanum tuberosum L.) is a member of solanaceae family and considered as one of the most valuable and widely distributed crops that is used for human food in most part of the world It has been realized that indiscriminate use of chemical fertilizers has affected the soil quality adversely in terms of decreasing organic carbon contents and development of micronutrients deficiencies and ultimately culminating into deterioration of produce quality (Naik and Khurana, 2003). This necessitates the immediate attention of researchers to evolve nutrient management strategies solving the problems of crop quality as well as soil conditions in holistic manner. Organic farming has potential for reducing some of the negative impacts of conventional agriculture to the environment and an option to restore the productivity degraded soils (Ghosh et al., 1998). In such practices; soil fertility is achieved by incorporating different kinds of soil amendments. fertility Furthermore; biofertilizers play a significant role in either synthesizing plant usable form of nutrients or increase the availability of nutrients already present in the soil. Application of P-solublizing bacteria would help in increasing the efficiency of available P in the soil by converting unavailable P into available form. Similarly, N fixing biofertilizers like Azotobactor take the potential to meet a successful availability of N requirement of potato (Giller and Cadisch, 1995). Therefore, the experiment has been undertaken to examine the influence of bio-fertilizers with different soil organic amendments in organic potato production.

Materials and methods

Experimental site and soil characteristics: The experiment was conducted at ‘Organic Block’ under the experimental field of Tuber Crops Research Centre, Joydebpur, Gazipur during 2019-20. Organic practices have been being followed in this block since 2015. After harvesting the crops in each year, the land was allowed to grow green manure like Sesbania sp. and they were fully decomposed before the commencing of the next season.  The experimental plot was a high land having sandy clay loam soil.

Methodology

Treatment details and planting method: Two bio-fertilizers namely Azotobacter and Phosphorus Soloblizing Bacteria (PSB) which dosage were each one 8 ml per kg seed potato in liquid form and three organic fertilizers with different dosages name 10 ton/ha and 8 ton/ha were chosen as the treatment. The number treatment was 8 namely T₁ : Control, T₂ : Vermicompost 10 t/ha, T₃ : Trico-compost 10 t/ha, T₄ : ACI Organic Fertilizer 10 t/ha, T₅ : Bio-fertilizer (Azotobacter + PSB), T₆ :  Vermicompost 8 t/ha + (Azotobacter + PSB), T₇ :  Trico-compost 8 t/ha + (Azotobacter + PSB, T₈ :  ACI Organic Fertilizer 8 t/ha + (Azotobacter + PSB). BARI Alu -25 was used as material produced under organic production system at organic block, TCRC, Gazipur following organic practices.From each two bio-fertilizer namely Azotobacter and Phosphorus Soloblizing Bacteria-(PSB) 400ml was taken into a large container and mixed with 40 litre water.  Than 50 kg seed tuber of BARI Alu-25 were soaked into the bio-fertilizer solution for half an hour. Soaked potato kept spreading on jute in shady place so that surface water might dried. Potato variety – BARI Alu 25 was planted on 22 November, 2021 maintaining the plant spacing with 60 cm × 25 cm in 3m × 3m unit plots. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Final harvesting of potato was done on the 27^th February, 2022. Data were taken on days to start of emergence, emergence (%) at 30 DAP, plant height at 45 & 60 DAP, number of stem per hill at 45 & 60 DAP, foliage coverage (%) at 45 & 60 DAP, plant vigor (1-10) Scale at 60 DAP, tuber Grade (% by number) & (% by weight, tuber fresh yield ton per hectare (t/ha) at 95 DAP, diseases and insects reaction, and Cost Benefit Ratio. Field Data were analyzed statistically and means were separated by using LSD through Statistix 10 statistical computer program.

Results and Discussion

There was significant variation among the treatments in all parameters like emergence percentage at 30 DAP, plant height at 45 and 60 DAP, number of stem per hill at 45 and 60 DAP, foliage coverage at 45 and 60 DAP, plant vigor at 45 and 60 DAP, (Table 1). Days to start of emergence was earlier in T₈ and T₅ treatment (11.00) days) which was followed by T₆ and T₇,respectively that was later in T₁.

The highest emergence percentage at 30 DAP was observed in T₈ treatment which was followed by T₆ and T₅ treatment whereas the lowest value was found from T₁ treatment (Control) (Table 1).

The maximum (48.33 cm) plant height was observed in treatment T₈ which was statistically identical with T7 whereas the minimum plant height was found from T1 (control) treatment.

Similar trend of variation was observed in case plant height at 60 DAP (Table 1).

The highest (4.43cm) number of stem/hill at 45DAP was recorded from treatment T₄ which was statistically similar with T2 and T2 whereas the lowest value (3.03) was found from T1 (control) treatment. Similar kind of result was found at 60 DAP (Table 1). In case foliage coverage percentage at 45 DAP, T₆ treatment which was treated with (Vermicompost 8 t/ha + (Azotobacter + PSB) gave the highest value (86.85%) which was followed. by T8 and T7 treatment, respectively whereas the lowest value (59.04%) was observed in T1 (control). At 60 DAP; similar pattern of tendency to produce foliage coverage was observed (Table 1).). In case of plant vigority, at 45 DAP; the maximum vigorous plant (8.80) was found from T₆ treatment which was treated with (Vermicompost 8 t/ha + (Azotobacter + PSB) whereas the minimum value was found from treatment T₁ (control) and at 60 DAP; T₁ treatmentdid the same trend to minimum plant vigority where maximum (9.20) plant vigority showed treatment T₈ (Table 1).

Table 1. Effect of integrated fertilizer management on Days to start of emergence, plant height, no. of stem/hill,

foliage coverage (%), plant vigor

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

*= Significant at 5% level of probability,    **= Significant at 1% level of probability                                                                                                       

Tuber grade (% by number) at 95 DAP

There was significant variation was found for all the treatments in the tuber grade (<28mm, 28-55mm and >55mm) (Table 2).

T₁ treatmentproduced the highest (30.42%) smaller sized tuber like <28mm whereas the lowest (13.14%) smaller sized tuber was found from T₃ which was statistically similar to T₅ (Table 2).

The highest (84.05%) tuber grade 28-55mm was found from treatment T₃ while the lowest (68.70%) tuber grade 28-55mm was found from T₁ which was statistically similar to with T₇.

In case large sized tuber >55mm, the maximum (7.27%) was produced by T₈ whereas the lowest (0.87%) was produced by T₁ (control)(Table 2).

Tuber grade (% by weight) at 95 DAP

The variation due to effect of treatment for all the tuber grade (<28mm,  28-55m and >55mm) was found significant (Table 2). The maximum (7.96%) smaller sized tuber grade <28mm was produced by T1 treatment whereas the minimum (1.20%) tuber grade <28mm was produced by T₈ treatment (Table 2).

The highest (89.16%) tuber grade 28-55mm was found from treatment T₃ which was treated with (Trico-compost 10 t/ha) and at par with T₁ treatment while the lowest tuber grade 28-55mm (77.13%) was found from T₇ treatment. In case large sized tuber >55mm, the maximum (24.52%) was produced by T₆ whereas the lowest (3.07%) was produced by T₁ (Table 2).

Fresh tuber yield at 95 DAP

At 95 DAP; tuber yield was varied significantly due to treatments effects. The maximum (18.27 t/ha) tuber yield was obtained from T₈ treatment which was treated with (ACI Organic Fertilizer 8 t/ha) + (Azotobacter + PSB)  was at par with T₆ and T₇ whereas the minimum fresh tuber yield was produced by treatment T₁ (control) (Table 1).

Table 2.Effect of integrated fertilizer management on tuber grade <28mm, 28-55mm and >55mm (% by number), (% by weight) at 95 DAP and final yield at 95 DAP

Means bearing same letter (s) do not differ significantly at 1 or 5% level of probability by DMRT

*= Significant at 5% level of probability,    **= Significant at 1% level of probability                                                                                                       

Economic analysis

Treatment T₈ showed the highest gross return (Tk. 657720/ha) and net return (Tk. 128720/ha) and Benefit Cost Ratio (BCR)-1.24 which was followed by treatment T_6. (Tk. 610920/ha) and net return (Tk. 81920/ha) and Benefit Cost Ratio (BCR)-1.15 and T₄ (Tk. 582120/ha) and net return (Tk. 77120/ha) and Benefit Cost Ratio (BCR)-1.15, respectively. The lowest gross return (Tk. 428760/ha), net return (Tk. 3760/ha and BCR-1.01) were found in treatment T₁ (Control). The results revealed that organic potato grown with treatment T₈, T₆ and T₄ is more profitable than the other practices.

Table 3. Cost of sweet potato cultivation per hectare

Table 4. Price of product

Table 5. Cost and return analysis of mulching and plant spacing on weed control and yield of sweet potato  system

during 2021-22

PSB= Phosphorus Soloblezing Bacteria

BCR= Benefit Cost Ratio

Conclusion

Considering all factors, potato seed tuber treated with bio-fertilizers might be practiced to produce organic potato which may be more profitable than other practices. Moreover, merely ACI Organic Fertilizer at the rate 10 t/ha also performed well to produce higher organic potato. But best performance was found from the T₈ treatment which was treated with (ACI Organic Fertilizer 8 t/ha + (Azotobacter + PSB). This is the 1^st year result and to be carried out next year to verify the result.

References

Ghosh, D. C. and Das, A. K. 1998. Effect of bio-fertilizers and growthregulators on growth and productivity of potato (Solanum tuberosum).Indian-Agriculturist. 42(2): 109-113.

Giller, K. E. and Cadisch, G. 1995. Future benefits from biologicalnitrogen fixation: An ecological approach to agriculture. Plant andSoil. 174: 255-277.

Naik, P. S. and Khurana, S. M. P. 2003. Micropropagation in potatoseed production: need to revise seed certification standards. J. IndianPotato Assoc. 30: 267-273.

EXPT. 8. EFFICACY OF BOTANICALS TO CONTROL VIRUS DISEASES TRANSMITTED BY APHIDS IN ORGANIC POTATO PRODUCTION.

M.K. ALAM, M.M.BEGUM, S. PARVIN AND M.H. RASHID

Abstract

An experiment was conducted to evaluate the efficacy of five different botanical pesticide to suppress the aphid infestation and thereafter incidence of two major virus diseases namely PLRV and PVY in potato field under organic management practices. The experiment was executed at the organic block under TCRC research field, Joydebpur during the year of 2021-22. Five botanicals namely rape seed oil, mahogony oil, neem oil, karam cha oil @ 2 ml/liter and Bioneem Plus (Azadiractin) @ 1ml/l were chosen as the treatment. BARI Alu 36 was used  under organic production system where soil fertility was managed with different organic fertilizers like Cow dung, Vermicompost, Trichocompost, and Neem Oil Cake @ 5t/ha each and different treatments were applied at 10 days interval from 30 days after planting to haulm pulling. Mean aphid number per ten plants as well as incidence of PLRV and PVY was recorded at three different dates (45, 60 and 75 DAP). At the initial date (45 DAP), neem oil performed better in reduction of aphid infestation (0.89 per 10 plants) while Bioneem plus gave the best result (2.39 and 3.85 per 10 plants) at the latter stages (60 and 75 DAP, respectively) and both were statistically similar. More or less similar trends were observed in case of viral diseases. Furthermore, plant vigority (8.33) as well as tuber yield (23.8 t/ha) were found better from the plot treated with Bioneem plus which was identical with neem oil.

Introduction

Potato (Solanum tuberosum) is currently the third most important food crops globally after rice and wheat, and over half of its production currently occurs in developing countries (Devaux et al. 2014). In Bangladesh, it is being grown as a commercial crop with a cultivated area over 4,77,400 ha and a production exceeding 10 million tonnes (BBS, 2019). The high production potential per unit area, high nutritional value and great taste make potato as one of the most important food crop in the world. Food safety is receiving increased attention worldwide and many countries have adopted organic policy to produce safe food. Bangladesh government also adopted National Organic Agricultural Policy in 2016 and potato is one of the selected crops in organic policy to be produced following organic practices. However, there are many constraints to produce organic potato specially to manage pest and disease of potato. In recent years, as temperatures increase virus vectors often become more abundent and the incidence of virus disease increases. It is estimated that virus diseases could decrease about 50% or more of the total yield potential (Harahagazwe et al. 2018).

PVY and PLRV are now the most damaging viruses of potato worldwide including Bangladesh, with PVY having overtaken PLRV as the most important. Tuber yield losses are caused by either of them in single infections and can reach more than 80% in combination with other viruses (Kreuze et. al, 2020). Hossain and Ali (1993) also claimed the fact that these two viruses are important in Bangladesh and reported that tuber yield could be reduced up to 78 and 95% by PLRV and PVY, respectively. Both viruses are transmitted by aphid vector and while aphids crossed the critical level (20 aphids/100 compound leaves) is quite difficult to control them (Awasthi and Verma, 2017). This is more applicable for organic production systems. There are several ways and means to achieve organic farming. The use of botanical pesticides is one such method which utilizes various plant products to achieve and ensure good crop health and has become really important in to-days agriculture specially in organic agriculture. Botanical pesticides are derived from plant extracts which are alternatives to chemical pesticides and are considered as eco-friendly as they break down into harmless compounds within hours or days in the presence of sunlight. Botanicals may contain a mixture of compounds, which can work together towards reducing a pathogen or pest with varying modes of action; therefore, using botanicals could lead to reduced occurrence of pathogen and pest resistance development (Shuping and Eloff 2017). Botanicals can in some cases also positively stimulate the plant’s metabolism and/or defenses, and consequently act as plant strengtheners (Dubeyet al. 2008; Guleria and Tiku 2009). Bangladesh has a rich source of plants that could be harnessed as botanicals. Among the botanicals, neem is regarded as the panacea for organic farming. Besides neem, there are many more botanicals namely rape seed oil, Mahogoni oil, karam cha oil etc. could be used in pest and disease suppression. Hence, this investigation was undertaken with the objective to find out the superior plant extract(s) to suppress aphid infestation as well as virus incidence.

Materials and methods

Experimental site and soil characteristics: The experiment was conducted at ‘Organic Block’ under the experimental field of Tuber Crops Research Centre, Joydebpur, Gazipur during 2021-22. Organic practices have been being followed in this block since 2015. After harvesting the crops in each year, the land was allowed to grow green manure like Sesbania sp. and they were fully decomposed before the commencing of the next season.  The experimental plot was a high land having sandy clay loam soil.

Methodology

Treatment details and planting method: Five botanicals such as Rape seed oil, Mahogony oil, Neem oil a Karam Cha oil @ 2 ml/liter and Bioneem Plus (Azadiractin) @ 1ml/l were chosen as the treatment and accordingly total treatment number including control (zero application) was six. Potato variety – BARI Alu 36 was planted on 24 November, 2021 maintaining the plant spacing with 60 cm × 25 cm in 3m × 3m unit plots. The experiment was laid out in a randomized complete block design (RCBD) with three replications.

Followed organic practices and standard: Soil fertility management was done following organic practices and standards. Cow dung, Vermicompost (VC), Trichocompost, and Neem Oil Cake (NOC); each one was applied @ 5t/ha. All organic fertilizers except NOC were applied as basal dose while NOC was applied in 3 equal installments. The first one was in pit and the other two installments were applied at the side of the row and covered with soil at the time of first and 2^nd time of earthing up followed by irrigation. Treatment was applied at one-week interval for 35 days after planting to second last week of harvesting (before haulm pulling). Intercultural operation, only weeding was done one time during the vegetative stage over the whole growing season. Data on aphid number per ten plant (about 100 compound leaves) and disease incidence of PLRV and PVY were  recorded at 45, 60 and 75 days after planting while plant vigor (1 – 10 scale; 1= very poor and 10 = best vigorous plant) was recorded by eye estimation at 60 DAP. Arcsine transformation method was used to convert data on disease incidence. Potato was harvested on February 27, 2022 and yield was calculated. Data were analyzed statistically and means were separated by using LSD through MSTATC statistical computer program.

Results and Discussion

There was no significant variation among the treatments in emergence percentage but statistical difference was ovserved in terms of mean number of aphid per ten plants at different dates as well as in plant vigority (Table 1). Neem oil performed better at initial date (45 DAP) to suppress aphid number per 10 plants (0.89) which was identical with Bioneem plus but statistically different from others. However, at the 60 and 75 DAP, the best aphid suppression (2.39 and 3.85 per 10 plants, respectively) was found by Bioneem plus which was followed by neem oil and was significantly similar. Among the botanicals, the poor performance (1.62 per 10 plants) was found in Rape seed oil for initial date (45 DAP) which was identical with karam cha oil. However, this result was inversed at 60 and 75 DAP; where Karam cha oil gave the least performance (3.73 and 6.91 per 10 plants, respectively) and was statistically similar with rape seed oil. These result suggests that neem based products (Bioneem plus and neem oil) significantly reduced the aphid number which was previously examined by many researchers (Schmutterer 1990; Patel &Srivastava 1989). This result might be due to phytotoxic effects of neem and thereafter playing the role as plant strengtheners which was confirmed earlier by Dubeyet al. (2008); Guleria and Tiku (2009). In case of plant vigority, the maximum vigorous plant (8.33) was found from the plot treated with Bioneem plus which was statistically similar with neem oil (7.97) but the poor performance (6.33) was observed in control plot and was identical with Karamcha oil (6.70).

Table 1. Effect of different botanicals on aphid population at different dates in organic potato field

Both PLRV and PVY infection was varied significantly among the treatments at different dates (Table 2). In case of PLRV, Bioneem plus gave the best performance for all dates except initial one (45 DAP). Here, neem oil showed good performance (1.48%) to suppress PLRV which was followed by Bioneem plus (1.87%) and was statistically similar. But in latter dates, the best performance was observed in Bioneem plus which was identical with neem oil. More or less similar trends were observed in case of PVY. Bioneem plus gave the best performance for all dates and was identical with neem oil and mahogony oil in most cases while the least performance was found in control and was significantly different from all treatments. There was significant variation among the treatments in terms of yield. The yield ranges from 23.8 to 16.7 tonnes per hectare. The highest yield (23.8 t/ha) was found in Bioneem plus treated plot which was identical with neem oil and mahogony seed oil but significantly different from other botanicals. The poor performance was found in control plot (16.7 t/ha) which was significantly different from all botanicals.

Table 2.Incidence of virus diseases and yield of potato as influenced by different botanicals.

Conclusion

Considering all factors, neem based products like Bioneem plus as well as neem oil could be choosen to control aphid as well as aphid transmitted viruses.

Reference

Awasthi, L. P and Verma, H. N. 2017.Current status of viral diseases of potato and their eco-friendly management – A critical review. Virology: Research& Reviews, vol 1(4):1-16. doi:10.15761/VRR.1000122.

Banngladesh Bureaue of Statistics (BBS). 2019. Yearbook of Agricultural Statistics 2018, Published by Ministry of Planning, Government of the Peoples Republic of Bangladesh; May, 2019. pp 321.

Devaux A, Kromann P, Ortiz O (2014) Potatoes for sustainable global food security. Potato Res 57:185–199

Dubey N K, Srivastava B, Kumar A. 2008. Current status of plant products as botanical pesticides in storage pest management. Biopesticides, 1, 182–186.

Guleria S, Tiku A. 2009. Botanicals in pest management: Current status and future perspectives. In: Peshin R, Dhawan A, eds., Integrated Pest Management: Innovation- Development Process. Springer, India. pp. 317–330.

Harahagazwe D, Condor B, Barreda C et al (2018) How big is the potato (Solanum tuberosum L.) yield gap in Sub-Saharan Africa and why? A participatory approach. Open Agriculture 3(1):180–189. https://doi.org/10.1515/opag-2018-0019

Hossain, M and Ali, M.S. 1993. Evaluation of promising entries of potato under infection pressure of potato leaf roll virus and potato virus Y. Bangladesh J. of Plant Path. 9 (1 &2), 5-7pp.

Kreuze J.F., Souza-Dias J.A.C., Jeevalatha A., Figueira A.R., Valkonen J.P.T., Jones R.A.C. (2020) Viral Diseases in Potato. In: Campos H., Ortiz O. (eds) The Potato Crop. Springer, Cham.https://doi.org/10.1007/978-3-030-28683-5_11

Patel, M.B. & K. P. Srivastava. 1989. Systemic action of neem seed substances against Pieris brassicae. Entomol.Exp. Appl. 54:297 – 300.

Schmutterer, H. 1990.Properties and potential of natural pesticides from the neem tree, Azadirachta Indica.Annu. Rev. Entomol. 35:271 – 297.

Shuping D S S, Eloff J N. 2017. The use of plants to protect plants and food against fungal pathogens: A review. African Journal of Traditional, Complementary, and Alternative Medicines, 14, 120–127.

EXPT. 9. EFFECT OF DIFFERENT BOTANICAL PESTICIDES TO CONTROL POTATO TUBER MOTH (PTM) UNDER STORAGE CONDITIONS

M.K. ALAM, M. J. HAIDER, S. PARVEEN AND M. SALIM

Abstract

Seven botanicals namely Lantana camara, Eucalyptus globulus, Tagetusminuta, Pyretherum flowers Azadiracthaindica, Nicotianatabacum and Menthaviridiswere evaluated against potato tuber moth including two checks (Talcum powder and untreated check)under storage conditions at TCRSC, BARI, Munshiganj during the year of 2021-22. BARI Alu 36 was used as material produced under organic production system at organic block, TCRC, Gazipur following organic practices. Similar size tubers were chosen and about 14 tubers weighed 1.0 kilogram. The tubers were surface sterilized and were shacked well with 25 g of the extract treated with talcum powder/1 kg tubers. The tubers were kept in the wooden box in ambient condition for natural infestation by PTM. Data recording is still continuing for further three dates. Till today, tuber infestation was reduced in botanicals. Botanicals perform superior to both controls (18.83 and 13.74% tuber infestation) in preventing the damage to potato tubers by potato tuber moth. Lantana showed the best result in tuber infestation (2.09%) which was followed by Neem (3.73%) and pyrethrum (4.56%). On the contrary, the lowest number of infestation holes per tuber was found inneem (0.22 per tuber) but it was at par with lantana (0.33).

Introduction

Organic farming is an alternative for sustainable and safe food production. This production system is becoming popular across the globe. The consumers particularly from developed countries prefer organic products considering its benefit and the trade in organic products is increasing at a significant rate (Willeret al., 2013). Potato represents a major food crop in many countries and it ranks 3^rd position among the crops grown in Bangladesh. Every year more than 10 million tonnes potato grows here but a great amount of potato is lost in the store mainly by Potato Tube Moth (PTM). The widely adopted method to control potato tuber moth is chemical insecticide which is prohibited in organic system. Therefore, it is important to search for alternatives that suit with organic system. Various studies have shown that botanicals have pesticides properties showing anti-feedant, repellent, growth regulators effects and/or toxic activities on a wide range of insect pests (Chandel et al., 2018 and Onu et al., 2015). They are treated as organic inputs and is found to be promising against PTM which had been investigated and supported by many authors (Sharaby et al., 2014; Ibrahim and Sisay, 2011; Luis, 2001). There is a very few information in context of Bangladesh and accordingly, this investigation has been undertaken to evaluate the efficacy of usage of seven plant extracts as organic pesticides against the PTM in storage conditions.

Materials and Methods
Plant Extracts Preparation:

All plant materials (treatments) used as organic pesticide were collected from locally available field. The name of plants used as treatments were Lantana camara, Eucalyptus globulus, Tagetusminuta, Pyretherum flowers Azadiracthaindica,Nicotianatabacumand Menthaviridisincluding two controls (talcum powder and untreated) and thus number of treatment was nine. After collection they were cleaned with tap water and were chopped into bits and were allowed to dry under shade for 2-3 weeks. The air-dried materials were grinded into fine powders using blender and kept in tight containers until use.  Different plant extract powder were soaked by ethanol 80% at a ratio of 1:4 (powder/solvent) as mentioned by Odey et al. (2012). Thereafter, the preparation were thoroughly mixed and filtered through Whatman filter paper No.42 to remove particulate matter and were stored in transparent bottles under refrigerator. The filtrate is considered as 100 per cent and were further used to prepare talc formulations (mixing with such an amount of talc so as to make it a solid powdered formulation and were kept it as such for up to 3-4 days in open shady conditions for proper drying).

Potato tuber source: The potato tubers were collected from TCRC, BARI, Gazipur where potato was grown in organic plot following organic practices. The tubers were quite similar size and about 14 tubers weighed 1.0 kilogram. The tubers were surface sterilized in 10.0% sodium hypochlorite solution for three minutes followed by rinsing in five changes of sterile tap water and the tubers were allowed to dry at room temperature for thirty minutes prior to the treatment with the plant extracts.

Treatment Application: Potato tubers were shacked well with 25 g of the extract treated with talcum powder/1 kg tubers until tubers were completely covered and the treated powders were stacked well to the tuber peel. The treated/untreated tubers were kept in wooden box (size 50 x 30 x 30 cm) in the potato shade in ambient condition for natural infestation by PTM.

Experimental setup: After the treatment with the plant extracts, the tubers were placed in surface sterilized wooden box at the rate of 42 - 45 tubers per box (weighed 3.0 kgs), replicated three times for each treatment. The experiment was arranged in a completely randomized design with seven botanicals and two controls (Talcum powder and absolute control). This postharvest experiment was set on April 25, 2022 at TCRSC, Munshigonj. Data recording was done at 10 days interval started from 5th Mayand to be continued until fully affected the control tubers. The experiment was evaluated based on percent tuber infestation and number of holes per tuber.

Results and Discussion

Data recording yet not completed and to be recorded further one month. Anyway, mean data are presented in Table 1 and Table 2. Data (Table 1) indicated that all botanicals perform superior to both controls (18.83 and 13.74% tuber infestation) in preventing the damage to potato tubers by potato tuber moth. Lantana showed the best result (2.09%) which was followed by Neem (3.73%) and pyrethrum (4.56%). Rajesh and Suman (2006) obtained similar efficacy results with L. camara in reducing potato tuber moth damage in storage conditions. L. camara was also recommended by Anonymous (2000) for use in stored tubers. 

Table 1.Effect of botanicals on potato tuber infestation by potato tuber moth

The numbers of infestation holes were also counted per tuber to note down the severity of infestation per tuber. The average number of infestation holes varied from 0.22 (neem) to 0.72 (tobacco), in different treatments, all being at par with each other as compared to 2.04 holes per tuber in control treatment.

All the tested products were 100 percent effective up to 30 days of treatments and were superior even after 100 days of the treatment with an average infestation of 2.09 – 7.39% as compared to control (18.83%). The tuber shape and quality was also good and resulted in normal sprouting.

Table 2.Effect of botanicals on the number of holes in tuber by potato tuber moth

Conclusion

This is the second year experiment and still data to be recorded for further 3 consecutive dates. However, in first year, more or less similar trends were observed in case of tuber infestation as well as damage index. Lanata showed the best performance in both cases in first year but in second year, although the lowest number of holes were found in neem which was at par with lantana. Anyway, it could be concluded that botanicals to be found promising to control the PTM under storage condition. Both years, natural PTM infestation was quite late and it would be better to draw the conclusion if artificial infestation of PTM could be done in next year.

Reference

Anonymous (2000) Package of Practices for Rabi Crops. Directorate of Extension Education, HPKV Palampur (Himachal Pradesh)

Chandel BS, Dubey I, Tewari A (2018) Screening of plant extract for insecticidal biopotancy against Callosobrucuschinensis L. (Coleoptera: Bruchidae) on chickpea, Ciceraritenum L. Int J Entomol Res 3(1):101–106

Ibrahim A, Sisay A. 2011. Evaluation of some botanicals to control potato tuber moth Phthorimaeaoperculella (Lepidoptera: Gelechiidae) at Bako, West Shoa, Ethiopia. East African Journal of Sciences, 5, 37–40.

Luis, G.O. 2001.Plants protecting other plants.Alternative methods to pest resistant.Magazine on low external inputs and sustainable agriculture.Action network on pesticides and their alternative in Latin-American. pp. 23-24.

Rajesh KV and Suman KV (2006) Photochemical and termiticidal study of Lantana camaravar aculeate leaves. Fitoterapia 77: 466-468

Odey, M.O., Iwara IA, Udiba UU, Johnson JT, Inekwe UV, Asenye ME, Victor O. 2012. Preparation of Plant extracts from Indigenous Medicinal Plants. International Journal of Science and Technology, Vol 1(12), 688-692.

Onu FM, Ogu E, Ikehi ME (2015) Use of Neem and Garlic dried plant powders for controlling some stored grains pests. Egypt J Biol Pest Control 25(2):507–512

Sharaby A, Rahman H A, Abdel-Aziz S S, Moawad S S. 2014. Natural plant oils and terpenes as protector for the potatotubers against Phthorimaeaoperculellainfestation by different application methods.EcologiaBalkanica, 6, 45–59.

EXPT. 10. EFFECT OF BOTANICALS TO CONTROL LATE BLIGHT DISEASE IN ORGANIC POTATO PRODUCTION

M.K. ALAM, S. PARVIN AND M. BEGUM

Abstract

An experiment was conducted to evaluate the efficacy of eight different botanical pesticide to suppress the mycelium growth in in vitro condition as well as to reduce the disease severity in organic field condition. The experiment was executed at TCRC, BARI Joydebpur during the year of 2021-22. Eight botanicals namely Me ntha virdis, Allium cepa, Azadirachta indica, Datura stramonium, Nicotiana tabacum, Lantana camara, Citrus limon and Corchorus capsularis (plant extract powder @ 2%) were chosen as the treatment. BARI Alu 63 was used under organic production system. In laboratory, mint, Neem, lantana were found to be effective to suppress the mycelium growth. More or less similar performance was observed in case of field condition. Lantana showed the best performance to reduce disease severity (3.12%) which was followed by neem (4.17%) and mint (5.08%), respectively and was statistically similar. Accordingly, the highest disease severity reduction over control (85.6%) as well the highest tuber yield (23.9 t/ha) was found in lantana which was followed by neem and mint.

Introduction

Potato is one of the most commercial crops grown in Bangladesh. Considering it’s contribution in food security as well as production trends, it has been chosen as one of the crops selected for organic production as per National Organic Policy in Bangladesh adopted in 2016. However, there are many constraints including disease management for organic potato production. Among the potato diseases, Late blight (PLB) is the most devastating which is caused by Phytophthora infestans. The only synthetic direct control measure allowed in organic potato production is the use of copper based products. However, it has also negative impacts on soil organism and is becoming banned in many countries including Europe (Buenemann et al. 2006). Accordingly, many researchers have investigated the potential of different botanicals and found the effectiveness to suppress the PLB (Forrer et al., 2017; Abayhne and Chauhan, 2016; Deshi et al., 2015 and Yusuf et al. 2011). There is acute shortage of relevant information in respect of Bangladesh. Hence, this study has been undertaken to investigate whether and how PLB could be controlled by utilizing different botanicals in organic potato production.

Materials and methods

Plant Materials and Extract Preparation: All plant materials (treatments) used as organic pesticide were collected from locally available field. Eight different plant material including leaves, seeds and fruits parts of different medicinal plants were used for the study and are highlighted in Table 1. After collection they were cleaned with tap water. These were chopped into bits and were allowed to dry under shade for 2-3 weeks. The air-dried materials were grinded into fine powders using blender and were kept in tight containers until use.  The technique described by Odey et al. (2012) was used with slight modifications. Each residue was used to prepare solutions of desired concentrations (2%) for test of antifungal activities in laboratory as well as to assess the efficiency by spraying in field condition. These stock suspensions were stored at 4⁰C and used within one week in case of rest of the excess suspensions.

Table 1. Botanicals used for the experiment analysis against P. infestans

Laboratory Experiment:

Isolation of Phytophthora infestans: 

The naturally late blight infected leaf samples were collected from the potato field in the laboratory and then rinsed under the running tap water. The abaxialside of late blight infected potato leaves were put on the mesh with wet tissue paper in the transparent plastic boxes and air tight properly. Then the plastic boxes were incubated at 18°C and after 7 days of incubation, a superficial whitish mycelial growth with sporulation was observed and then had taken some media block using the sterile needle and touch the upper surfaces of leaves for catching the sporangia using sterile scalpel and then streak on the fresh pea agar media. Then, inoculated media incubated at 18°C and after 7 days of incubation, whitish mycelial growth observed on the media and then confirmed also under the microscope to observe the lemon shaped sporangia at the end of the sporangiophores with hyaline mycelia without cross walls.

Preparation of different botanicals fortified pea agar media:

The isolate Phytophthora infestans that were successfully cultured were tested for sensitivity to different organic products on pea agar.  A total of eight organic plants powder including one control and one fungicide under mancozeb group were considered for this bioassay to observe the inhibitory effect of P. infestans under laboratoty condition. Under this method, the pea agar plates were amended with 2 mg/ml of each product and then mycelial plugs from 14 days old P. infestans cultures were transferred to the plates at the centered portion. The plates were kept in the incubator at 18⁰C in light 12hrs and 12 hours in dark up to 14 days alternately. After 14 days, the radial growth of P. infestans was measured on the plates. The design was followed CRD with three replications. The growth were measured the maximum length and breadth in centimeter and calculated area by multiplying length and breadth. 

Field Experimental site and soil characteristics: The experiment was conducted at ‘Organic Block’ under the experimental field of Tuber Crops Research Centre, Joydebpur, Gazipur during 2021-22. Organic practices have been being followed in this block since 2015. After harvesting the crops in each year, the land was allowed to grow green manure like Sesbania sp. and they were fully decomposed before the commencing of the next season.  The experimental plot was a high land having sandy clay loam soil.

Treatment details and planting method for field experiment: Eight botanicals mentioned in Table 1 were applied (@ 2%) as the treatment and accordingly total treatment number including control (zero application) was nine. Potato variety – BARI Alu 63 was planted on 25 November, 2021 maintaining the plant spacing with 60 cm × 25 cm in 3m × 3m unit plots. The experiment was laid out in a randomized complete block design (RCBD) with three replications.

Followed organic practices and standard

Soil fertility management was done following organic practices and standards. Cow dung, Vermi compost (VC), Tricho compost, and Neem Oil Cake (NOC); each one was applied @ 5t/ha. All organic fertilizers except NOC were applied as basal dose while NOC was applied in 3 equal installments. The first one was in pit and the other two installments were applied at the side of the row and covered with soil at the time of first and 2^nd time of earthing up followed by irrigation. Treatment was applied at one-week interval from 35 days after planting to second last week of harvesting (before haulm pulling). Intercultural operation, only weeding was done one time during the vegetative stage over the whole growing season.

Data Recording:

Data on severity of late blight disease was assessed with one week interval, starting at two months after planting until three months old. Disease severity was assessed by estimating leaf area infected and damaged by the disease. In this regard, late blight disease severity was determined according to Andrivon et al. (2006) using a 0 – 9 scoring scale where: 0 = No lesions, 1 = a few circles, 2 = up to 5%, 3 = 5.1 – 10%, 4 = 10.1 – 25%, 5 = 25.1 – 50%, 6 = 50.1 – 75%, 7 = 75.1 – 85%, 8 = 85.1 – 95% and 9 = 95.1 – 100% leaf area covered with late blight symptom. The percentage of disease severity reduction was calculated as: 100(1 – x/y), where x and y are the disease severity index for the specific treatment and control plants, respectively. Potato was harvested on March 03, 2022 and yield was calculated. Data were analyzed statistically and means were separated by using LSD through MSTATC statistical computer program.

Results and Discussion

Effects of Botanicals on growth of P. infestans under laboratory condition:

Eight organic plants powder including one control (using only pea agar media) and one fungicide under mancozeb group were considered for this bioassay to observe the inhibitory effect of P. infestans in vitro. Extracts of three botanicals viz., Mint, Neem, lantana among eight botanicals and chemicals were found to be more effective to suppress the mycelium growth (Fig. 1 and Plate 1), whereas other five botanicals did not  inhibit the mycelium growth of P. infestans. Rashid et.al,.(2004) also reported that the extract of neem (Azardichta indica) has good inhibitory effect against P. infestans spore germination.

Figure 1. Inhibitory effects of different botanicals on the growth of P. infestans caused late blight of potato

Plate 1. In Vitro evaluation of botanical extracts against P. infestans.

Table 2. Effects of different botanicals on disease severity and yield of organic potato

Effects of botanicals in field condition: There was significant variation among the treatments in respect of disease severity as well as in yield of potato. Lantana showed the best performance (3.12%) to reduce disease severity which was followed by neem and mint, respectively and was statistically similar. Accordingly, percentage of disease severity reduction was observed among these three botanicals. More or less similar trends were observed in case of tuber yield. The highest tuber yield (23.9 t/ha) was found in lantana which was followed by neem and mint, respectively.

The current study indicates that some botanical extracts have anti-fungal activity against mycelium growth of P. infestans. The finding of this study is an agreement with the study of previously reported authors (Forreret al., 2017; Abayhne and Chauhan, 2016; Deshi et al., 2015 and Yusuf et al. 2011). The possible reason for this effect that each plant contains different components in the form of secondary metabolites that have different modes of action on different microbes and may result in variable results (Tiwari et al, 2011). The presence of antimicrobial substances in the higher plants is well established (Srinivasan et al, 2001). Accordingly, they have the potential in reducing the effects of the plant pathogen like P. infestans.

Conclusion

In the end, most of the plant extracts except datura, onion and lemon exhibited promising antifungal activity against the P. infestans mycelial growth. Similar trends were also observed in field condition to inhibit the late blight disease. Various products of medicinal plants deserved to be reliable source for active antifungal agents and might play significant role for future practical applications in a socially and ecologically healthy management of late blight of potatoes.  This is second year result which is quite similar to first year observation. 

Reference

Abayhne M A, Chauhan N M. 2016. Antifungal activity of various medicinal plants against late blight of potato from Ethiopia.Journal of Scientific Research and Reports, 12, 1–9.

Andrivon, D.; Pelle, R.; Ellisseche, D. Assessing resistance types and levels to epidemic diseases from the analysis of disease progress curves.Am. J. Potato Res.2006, 83, 455–461

Buenemann, E.K.; Schwenke, G.D.; Van Zwieten, L. Impact of agricultural inputs on soil organisms—A review. Aust. J. Soil. Res. 2006, 44, 379–406.

Deshi S, Wonang D, Imoni E, Gowok H G. 2015. Efficacy of naturally occurring antifungal agents from five plants for the control of late blight (Phytophthorainfestans) on Irish potato.International Journal of Scientific of EngineeringResearch, 6, 1990–2004.

Forrer H R, Vogelgsang S, Musa T. 2017. Botanicals and phosphonate show potential to replace copper for control of potato late blight. Journal of Fungi, 3, 65.

Hadian S. (2012). Antifungal Activity of some Plant Extracts against some Pathogenic Fungil in Iran.Asian J. Exp. Bio. Sci. 3(4): 718.

Odey, M.O., Iwara IA, Udiba UU, Johnson JT, Inekwe UV, Asenye ME, Victor O. 2012. Preparation of Plant extracts from Indigenous Medicinal Plants. International Journal of Science and Technology, Vol 1(12), 688-692.

Yusuf Y, Izzet K, Ayhan G, Ibrahim D, Nezhun G, Halit C, Mark W. In vitro antifungal activities of 26 plant extracts on mycelial growth of Phytophthorainfestans (Mont.) de Bary. Afr. J. Biotech. 2011;10:2625-2629.

Rashid A, Ahmad I, Iram S, Mirza JI, Rauf CA. Efficiency of different neem (Azadirachtaindica A. Juss) products against various life stages of Phytophthorainfestans (MONT) De Bary. Pak. J. Bot. 2004;36:881-886.

Srinivasan D, Nathan S, Suresh T, Perumalsamy O. Antimicrobial activity of certain Indian medicinal plants used in folkloric medicine. J. Ethnopharmacology. 2001;74:217-220.

TiwariP, Kumar B, Kaur M, Kaur G,Kaur H. Phytochemical screening and extraction: A review. Int. Pharma. Sci. 2011;1:98-106.

EXPT. 11. EFICACY OF BOTANICALS TO CONTROL SOFT ROT DISEASE OF ORGANIC POTATO UNDER STORAGE CONDITION

M.K. ALAM, M. BEGUM, S. PARVEEN AND M. SALIM

Abstract

An experiment was conducted to evaluate the efficacy of seven different botanicals to suppress the bacterial growth in in vitro condition as well as to reduce soft rot disease under storage conditions. The in vitro part was conducted at TCRC, BARI, Gazipur while storage part was conducted at TCRSC, BARI, Munshiganj during the year of 2021-22. Seven botanicals namely Allium cepa (seed), Allium sativum (leaves), Azadirachta indica (leaves), Capsicum annum (Fruits), Nicotiana tabacum (leaves), Lantana camara (leaves) and Swertia chirayita (whole plant) were chosen as the treatment including two control bleaching powder and zero control. BARI Alu 36 was used as material produced under organic production system at organic block, TCRC, Gazipur following organic practices. Plant extracts were collected following standard procedures and were tested to control soft rot disease of potato in in vitro as well as under storage condition. In laboratory, Chirota and lantana were found to be effective to suppress the bacterial (E. carotovara.) growth. More or less similar performance was observed in case of storage condition. Chirota showed the best performance (4.77%) to suppress disease incidence which was followed by lantana (5.95%) and was statistically similar. However, percentage of severity of tuber soft rot was observed better (3.39%) in case of neem which was followed by chirota and lantana, respectively and was statistically similar. The poor disease severity performance (28.6%) was observed in case of control treatment. 

Introduction

All over the world, current agricultural practices are moving away from the use of synthetic chemicals due to their adverse effects on ecosystem. Considering the negative consequences on environment and natural habitats, researchers are looking for alternate options and organic agriculture has the potential to serve this purpose. Accordingly, many countries have adopted organic policy across the world and Bangladesh is not exceptional from them. She has adopted organic agricultural policy in 2016. Potato is one of the most commercial crops grown in Bangladesh. Considering it’s contribution in food security as well as production trends, it has been chosen as one of the crops selected for organic production in our national Organic Agricultural Policy. However, there are many constraints including disease management, specially during storage condition of organic potato. Soft rot of potato in storage condition is a major disease and can cause substantial losses due to proper management. Organic potato to be managed organically rather than using harmful chemicals and in this case, botanicals could serve the purposes of harmful agro-chemicals. Green plants are a huge reservoir of various effective chemotherapeutics and could serve as an environmentally friendly natural alternative to the toxic chemical pesticides (Hostettmann and Wolfender, 1997).Some plant extracts were documented as effective inhibitors of phytopathogenic bacteria (Leksomboonet al., 1998). Many investigators have found that botanicals have the potential of antimicrobial activities against bacterial soft rot of potatoes (Krebs and Jaggir, 1999 and Long et al., 2003). However, a little information is available in context of Bangladesh and hence this study has been undertaken to find out promising botanicals to control the soft rot bacterial pathogens in Bangladeshi potatoes.

Materials and methods

             Preparation of plant extracts: A total of seven plants namely Allium cepa (seed), Allium sativum (leaves), Azadirachta indica (leaves/seed), Capsicum annum (Fruits), Nicotiana tabacum (leaves), Lantana camara (leaves) and Swertia chirayita (whole plant) were used for the preparation of extract powder for laboratory experiment as well as extract solution at the ratio of 1 : 10 (w/v) in water for application as treatment in storage experimental part. After collection they were cleaned with tap water. These were chopped into bits and were allowed to dry under shade for 2-3 weeks. The air-dried materials were grinded into fine powders using blender and were kept in tight containers until use. The crushed materials (grinded powder) were mixed with distilled water at 1: 10 (w/v) and blended in an electrical blender. They were filtered through double layered muslin cloth followed by Whatman No. 1 filter paper. The extracts were poured into conical flasks and was used as stock solution. Mouth of each flask was closed with aluminum foil and preserved in a refrigerator at 4°C for further use in future.

Laboratory Experiment (In Vitro):

Collection of Erwinia carotovora and botanical products:

The isolate of soft rot causing bacteria Erwinia carotovora was collected from the Plant Pathology division, BARI, Joydebpur, Gazipur and preserved in King’s B media for subsequent study. There were seven botanical powder product used as treatment and prepared as mentioned above.

Preparation of different botanicals fortified  pea King’s B media:

The isolate Erwinia carotovora that were successfully preserved and tested for sensitivity to different organic products on king’s B media.  A total of seven organic plants powder including one control were considered for this bioassay to observe the inhibitory effect of E. carotovoraunder laboratoty condition. Under this method, the king’s B media ( 38 g King’s B agar and 10 ml glycerol mix with one litre water) were also amended with 0.1% and 0.2%  of each product and then one loop of bacterial colony from 48 hours old  E. carotovoracultures were transferred to the plates by streaking on the fortified media separately. The plates were kept in the incubator at 20⁰ C in light 12 hrs and 12 hours in dark up to 3 days alternately. After 3 days, the growth of E. carotovorawas measured on the plates as percentage basis. The design was followed CRD with three replications.

Storage Experiment location and Potato tuber source: 

The storage experimental part was carried out at TCRSC, Munshiganj but potato tubers were collected from TCRC, BARI, Gazipur where potato was grown in organic plot following organic practices. The tubers were quite similar size and about 14 tubers weighed 1.0 kilogram. The tubers were surface sterilized in 10.0% sodium hypochlorite solution for three minutes followed by rinsing in five changes of sterile tap water and the tubers were allowed to dry at room temperature for thirty minutes prior to the treatment with the plant extracts.

Tuber treatment with plant extracts: The chosen tubers were sprayed with individual treatment (plant extract) to run –off (approximately at the rate of 100 ml per 100 tubers) using a hand sprayer. Hand sprayer was cleaned with distilled water every time immediate after use of each treatment. All the tubers were allowed to dry before experiment setup.

Experimental setup: After the treatment with the plant extracts, the tubers were placed in surface sterilized netted wooden shelf (each chamber about 20 x 60 cm) with lids at the rate of 42 - 45 tubers per chamber, replicated three times for each treatment. The experiment was arranged in a completely randomized design with seven botanicals and bleaching as a positive control treatment in addition of negative control where tubers were sprayed with only distilled water. This postharvest experiment was set on April 06, 2022 at TCRSC, Munshiganj. Data recording was done at 10 days interval started from 26th April, 2021 and still to be continued until full rotten of tubers of the negative control treatment. The experiment was evaluated based on the incidence and severity of the tuber soft rot. The tuber soft rot severity was assessed on a scale of 0–5 with moderate modification as described by Bdliya and Langerfeld (2005) where:

0 = no symptom of rot

1 = 1–15% of tuber rotten

2 = 16–30% of tuber rotten

3 = 31–45% of tuber rotten

4 = 46–60% of tuber rotten

5 ≥ 61% of tuber rotten.

The severity was then computed using the formula

S = (∑n/Nx5) x 100

where:  S = severity of tuber rot (%); (∑n = summation of individual ratings; N = total number of potato tubers assessed and 5 = highest score on the severity scale

Data were analyzed statistically and means were separated by using LSD through MSTAT-C statistical computer program.

Results and Discussion

Effects of Botanicals on growth of E. carotovoa under laboratory condition:

Seven organic plants powder including one control (using only King’s B media) was considered for this bioassay to observe the inhibitory effect of E. carotovora in vitro. Regarding 0.1% of extracts of botanicals, none botanicals were found to be more effective to suppress the bacterial growth  of E. carotovora (Fig. 1 and Plate 1) except Chirota (Swertia chirayita) . The extract of Chirota (Swerita chirata) inhibited 60% the bacterial growth in the media. In case of 0.2% extracts of botanicals two botanicals namely Chirota (Swerita chirayita) and Lantana (Lantana camara) inhibited the bacterial growth of E. carotovora by 80% and 60%, respectively. The extract of Chirota (Swertia chirayita) found good inhibitory effect against E. carotovora under both concentration of botanical extracts by 60%  and 80% at 0.1% and 0.2%, respectively.

             Figure 1. Inhibitory effects of different botanicals on the growth of E. carotovora caused soft rot       

                             of potato using 0.1% and 0.2%.

        Plate 1. Inhibitory effects of different botanicals at 0.1% on the growth of E. carotovora caused soft rot of potato

    Plate 2. Inhibitory effects of different botanicals at 0.2% on the growth of E. carotovora caused soft rot of potato

Effects of botanicals under storage condition: There was significant variation among the treatments in respect of disease incidence and percent severity of tuber rot (Table 1). The highest disease incidence (24.6%) was observed in (negative) control treatment which was statistically different from all other treatments. Chirota showed the best performance (4.77%) to suppress disease incidence which was followed by lantana (5.95%) and was statistically similar. Positive control bleaching (6.36%) was identical with most of the botanicals except chilli and onion. Although chirota and lantana gave the best performance in disease incidence, percentage of severity of tuber soft rot was observed better (3.39%) in neem which was followed by chirota and lantana, respectively and was statistically similar. The least performance (28.6%) was observed in case of control treatment which was significantly difference from all others. 

Table 1. Effects of different botanicals on disease incidence and percent severity of tuber rot

The current study indicates that some plant extracts have effectiveness against growth of bacteria (E. carotovara) in in vitro condition. These botanicals include chirota and lantana with different concentration. Similar findings were obtained from the same botanicals in storage condition.  However, good results were obtained from the extract of neem in addition to chirota and lantana in storage condition. The finding of this study is an agreement with the study of previously reported authors (Krebs and Jaggir, 1999 and Long et al., 2003). The possible reason for this effect may be due to antimicrobial components present in plant extracts which is well established in the higher plants (Srinivasan et al, 2001).

Conclusion

The results of this study showed that the chirota, lantana and neem extracts significantly reduced the incidence and severity of the tuber soft rot and could therefore be used to reduce losses due to the disease in storage. Spraying of tubers requires less volume of extracts and is much easier to apply thus could be easily adopted by farmers. This is the second year result which is in line with the findings of the previous year. However, more research is needed to determine the degree of penetration of the extracts into the lenticels so as to ascertain the efficacy of the extract in controlling latent infection which is the predominant mode of contamination of potato tubers by the soft rot caused by E. carotovora spp. Furthermore, antibacterial activity of different botanicals against soft rot bacteria under in vitro condition with different botanicals at various concentration is necessary to draw final recommendation and accordingly, more in vitro investigation with potential botanicals at different concentrations to be carried out in next year.

References

Bdliya B.S., Langerfeld E. 2005. Soft rot and Blackleg [Erwiniacarotovora ssp. atroseptica (Van Hall) Dye] of potato as affected by inoculum density and variety. Nigerian J. Plant Protection 22: 65–75.

Hostettmann K.and J. L. Wolfender, “The search for biologically active secondary metabolites,” Pesticide Science, vol. 51, no. 4, pp. 471–482, 1997.

Krebs H. and W. Jaggir, “Effect of plant extracts against soft rot of potatoes: Erwiniacarotovora Flora and Fauna n Industrial Crops,” Agrarforschung, vol. 6, no. 1, pp. 17–20, 1999.

Long, H. H., N. Furuya, D. Kurose, M. Takeshita, and Y. Takanami, “Isolation of endophytic bacteria from Solanum sp. and their antibacterial activity against plant pathogenic bacteria,” Journal of the Faculty of Agriculture, Kyushu University, vol. 48, no. 1-2, pp. 21–28, 2003.

Leksomboon, C. N. Thaveechai, and W. Kositratana, “Effect of Thai medicinal plant extracts on growth of phytopathogenic bacteria,” in Proceeding of the 36th Kasetsart University Annual Conference, Plant Section, Kasetsart University, Bangkok, Thailand, February 1998.

Srinivasan D, Nathan S, Suresh T, Perumalsamy O. Antimicrobial activity of certain Indian medicinal plants used in folkloric medicine. J. Ethnopharmacology. 2001;74:217-220.

EXPT. 13.  ADAPTIVE TRIAL WITH NEWLY RELEASED POTATO VARIETIES

                                                  M. SALIM, R. AKTER AND M. K. ALAM               

Abstract

An Adaptive trial was conducted with some progressive  farmer’s field at four different locations namely Tongibari, Sirajdikhan, Lowhajang and Sadar, Munshigonj under the supervision of Tuber Crops Research Sub-Centre, Munshiganj during 2021-2022 to popularize and collect the feedback of the newly released improved potato varieties and thus increase the total national yield of Bangladesh. The experiment was performed with ten newly released potato varieties namely BARI Alu-36, BARI Alu-37, BARI Alu-40, BARI Alu-41, BARI Alu-47, BARI Alu-48, BARI Alu-50, BARI Alu-56, BARI Alu-57 and BARI Alu-62 maintaining line to line spacing 60cm and plant to plant spacing 25cm in10 m x 11m plot size with a view to observe the performance of these varieties in the farmers’ field and to ensure farmer’s participation for the expansion of BARI released new varieties. Considering the yield and other characters BARI Alu-47 (46.89 t/ha), BARI Alu-48 (41.01 t/ha), BARI Alu-40 (40.72 t/ha), BARI Alu-50 (38.03 t/ha) and BARI Alu-36 (36.19 t/ha) were found better which may be recommended for commercial cultivation at Munshiganj region.

Introduction

The Tuber Crops Research Centre of BARI has developed number of potato varieties with some special criteria through screening since last few years. These varieties are high yielding but these are not yet under cultivation in a large scale throughout the country.  In true sense, end users are the decision maker for the fate of new  released variety, so therefore this study was under taken with a view to promote and explore the farmer’s response regarding the new ones.

Materials and Methods

The farmers’ field trial was conducted with ten newly released varieties viz. BARI Alu-36, BARI Alu-37, BARI Alu-40, BARI Alu-41 BARI Alu-47, BARI Alu-48, BARI Alu-50, BARI Alu-56, BARI Alu-57 and BARI Alu-62having no replications during the rabi season of 2021-2022. Location was denoted to four different Upazillas like Tongibari, Sirajdikhan, Lowahajang and Sadarin Munshiganj. The soil of the locations is mainly flood plain sandy loam and is suitable for potato cultivation. Recommended doses of fertilizers were applied @ 265 kg Urea, 220 kg TSP, 280 kg MP, 85 kg Gypsum, 14 kg ZnSO₄ and 12 kg Boric Acid per hectare. At the time of planting, Ecofuran 5G was applied to the soil against cut worm and other soil pests.The date of planting varied from the 02December, 2021 to 05^th January, 2022. Plot size for each variety was 10m X 11m. Line to line spacing was 60cm and plant to plant spacing was 25cm.Haulm pulling were done at 88 DAP and Crops were harvested 7 days after haulm pulling. The final harvest was done at 95 DAP. Rouging of disease plants was done in the improve practice at least two times, one at 30-35 DAP and another at 50-60 DAP. Data on number of rouged out plant, diseases, yield and yield contributing characters was recorded and also keeping the farmers opinion about new varieties.

Results and Discussion

Table 1.Yield of BARI released potato varieties under Adaptive Trial in Munshiganj during the year (2021-2022)

The results obtained from the field trial of different locations of Munshiganj region are presented in the Table 1. From this table it is observed that the maximum mean yield (47.25 t/ha) over location was obtained from Lowhajang location which was followed by Tongibari location (35.92 t/ha). A devastating Cyclone-Jaowad occurred in Munshiganj during 5-7 December, 2021 which greatly affected on potato field. In addition of yield, insects and diseases reaction was also influenced by planting time which was quite changed due to cyclone - Jaowad. At Loc-1, potato was planted on 2^nd December just 3 days before of Jaowad but the yield was highest. That plot was less affected by Jaowad as the land was slopy of that particular field which allowed rain water to drain out easily. Furthermore, comparatively long winter duration was prevailed in that location which ultimately resulted in higher yield. On the contrary, the poor yield (28.32 t/ha) was obtained from the location Sirajdikhan. This might be due to late planting as the topography of that location was low to medium low land. The potato was planted at Sirajdikhan on 5^th January, 2022 while the planting date of medium yield (35.92 t/ha) producer location was 23^rd December, 2021. It indicates that potato yield decreases with the delay of planting time.

The highest mean yield (46.89 t/ha) over varieties was found from BARI Alu-47 which was followed by BARI Alu-48 (41.01 t/ha), BARI Alu-40 (40.72 t/ha) and BARI Alu-62, respectively. At Lowhajang location, BARI Alu–47 gave the maximum yield (60.16 t/ha) which was followed by BARI Alu 40 (51.95 t/ha). More or less similar trend was also observed in case of Sirajdikhan location where BARI Alu–47 performed the best yielder (41.01 t/ha). Although BARI Alu-47 was not the highest yielder (39.50 t/ha) in case of Tongibari location, it was at par with maximum producer (41.02 t/ha) resulted from BARI Alu-48. 

In contrast, the lowest mean yield (29.49 t/ha) over varieties was obtained from BARI Alu-37 which was followed by BARI Alu-57 (30.07 t/ha). In Lowhajang location, BARI Alu-57 showed least performance (34.97 t/ha) which was followed by BARI Alu -37 (37.19 t/ha). However, BARI Alu-37 gave the poor performance (26.64 t/ha) in Tongibari location. The poor yield at Lowhajang location was obtained from none of these two varieties (BARI Alu 37 and BARI Alu-57). The poor yield (21.17 t/ha) was observed in case of BARI Alu-57 which was at par with BARI Alu-37 (24.64 t/ha).

Table 2: Economic analysis of potato varieties at Munshignj region during 2021-2022

Potato Price (Tk kg^-1) = 12

Economic analysis

Highest gross return (Tk.5,62,680), gross margin (Tk.2,84,180) and BCR (2.02) was recorded from BARI Alu-47 which was followed by BARI Alu-48 and BARI Alu-40 (Tk. 4,92,140, Tk. 2,13,620 and 1.77) (Tk. 4,88,640, Tk. 2,10,140 and 1.75), respectively). The lowest economic return was recorded from BARI Alu-37 (BCR 1.27).

Table 3. Diseases and insects reaction of BARI released potato varieties under Adaptive Trial at Munshiganj region (2021-2022)