INFLUENCE OF VERMICOMPOST ON GROWTH AND YIELD OF OKRA ( Abelmoschus esculentus ) IN COASTAL AREA OF BANGLADESH

An experiment was conducted at the research field in the Department of Agriculture, Noakhali Science and Technology University, Noakhali, Bangladesh during the period from March to July 2022 to study the effect of vermicompost on growth and yield of okra. The experiment was laid out in a Randomized Complete Block Design (RCBD) comprising four treatments with three replications


Okra
Vermicompost Growth Yield Coastal area An experiment was conducted at the research field in the Department of Agriculture, Noakhali Science and Technology University, Noakhali, Bangladesh during the period from March to July 2022 to study the effect of vermicompost on growth and yield of okra.The experiment was laid out in a Randomized Complete Block Design (RCBD) comprising four treatments with three replications.The four treatments were T0 (Control), T1 (Vermicompost 10 t ha -1 ), T2 (Vermicompost 15 t ha -1 ) and T3 (Vermicompost 20 t ha -1 ).Green finger F1 okra used as planting material.Data were recorded from different stages of plant growth viz, plant height, days of flowering, fruit per plant, fruit length, fruit diameter, fruit weight, fruit weight per plant, yield per plot and yield per hectare.All the recorded parameters were statistically significant (P<0.01).The maximum days to first flowering (47.31 days) was recorded from T0 (Control), while the minimum days for first flowering (40.67 days) was found from treatment T3 (Vermicompost 20 t ha -1 ).The maximum height of okra plant (100.43 cm), number of fruits per plant (22.13), fruit length (13.60 cm), fruit diameter (2.01 cm), fruit weight (13.47 g), fruit weight per plant (198.02g), yield per plot (1.78 kg), yield per hectare (17.8 t ha -1 ) were found in treatment T3 (Vermicompost 20 t ha -1 ) whereas lowest data recorded in treatment T0 (Control).
Observing the results, it can be stated that application of vermicompost @ 20 t ha -1 for okra cultivation gave better growth and yield in the coastal area of Bangladesh.

INTRODUCTION
Okra (Abelmoschus esculentus) is a popular vegetable throughout the tropical and subtropical parts of the world, as well as in Bangladesh (Shahriazzaman et al., 2014).It belongs to family of Malvaceae (Maurya et al., 2013).It is an annual crop grown mainly as fruits vegetables in the world (Chowdhury et al., 2014).It is critical in meeting the country's vegetable needs when vegetables are scanty in the market (Ahmed, 1995).Okra can be grown throughout the year but mainly grown in summer season of Bangladesh.It is a rich source of vitamins, minerals and is useful against various diseases (Gemede, 2015).The world's growing population has increased food demand and inundated current agricultural land resources.(Hussain et al., 2011).In most developing nations, higher food production has become an ultimate objective in order to meet the significant growth in population.(El-Shaikh and Mohammed, 2009).Vegetables are the most significant food crop in terms of cultivation and consumption (Ali et al., 2022a;Ali et al., 2023b).In general, vegetables are grown all over the world utilizing a variety of inputs such as chemical fertilizers and pesticides, organic fertilizers, biofertilizers and biopesticides, etc.In recent years, the use of various organic fertilizers, biofertilizers, and biopesticides has been suggested not only to reduce the use of dangerous chemical inputs but also for sustainable crop production notably in the cultivation of vegetables.(Gandhi and Sundari, 2012).Fertilizers provide the plant nutrients necessary for healthy growth.Plant nutrients are divided into two groups, one is known as macronutrient and other is known as micronutrient that plays important roles in the plants metabolism.Organic fertilizers such as compost or manure made from vegetative debris or animal excreta that also provide the plant nutrients for crop production.
Vermicompost is the droppings of earthworms following the intestinal digestion of organic materials.Vermicompost is a low-cost organic material produced by the bio-oxidation of organic substrates, which combines the synergistic effects of earthworms and microorganisms.(Lim et al., 2016;Baghel et al., 2018).Okra production is increased by the use of vermicompost.It increases microbial activity in soil by which increased the production of okra (Narkhede et al., 2011).It enhances soil bulk density, water retention capacity, pH, and electrical conductivity better than conventional compost or raw material (Doan et al., 2015).It plays an important role for sustainable soil fertility and productivity.It also enhances the growth and development of crops and increases the yield (Kaur et al, 2015).Numerous biotic and abiotic stress have a significant impact on okra production.Soil salinity is one of the factors influencing okra yield and cultivation in various regions of the world.Salinity in the soil has a detrimental influence on crop quality, production, and growth.(Ali et al., 2023;Ali et al., 2022;Dong, 2008).Okra is quite susceptible to soil salt, especially during the growing phases.Due to salinity in many coastal locations of Bangladesh, acceptable okra producing conditions are dwindling.Okra is one of the important vegetable but soil salinity hamper its cultivation.Vermicompost management is a factor that can be used to increase okra production in coastal area of Bangladesh.Keeping this in mind, the present research work has been undertaken to find out an optimum dose of vermicompost for yield maximization of okra in coastal area of Bangladesh.

Experimental site and soil
The experiment was conducted at the research field of the Noakhali Science and Technology University, Noakhali, Bangladesh during the period of March to July 2022.The field belongs to the agro-ecological region of the Young Meghna Estuarine floodplain (AEZ-18).The experiment field was a flat plot of land with sandy loam with having soil pH (7.5) and soil salinity of 4.32 dSm -1 .

Experimental treatments and design
Single factor experiment was designed using Randomized Complete Block Design (RCBD) with four treatments and three replications.The treatments were T0 (Control), T1 (Vermicompost 10 t ha -1 ), T2 (Vermicompost 15 t ha -1 ) and T3 (Vermicompost 20 t ha -1 ).The experimental area was split into three blocks, each indicating a replication.Each block was divided into 4 plots, there were 12 units plot altogether in the experiment.Each plot was 1m x 1m in size.The distance between two plots were kept 0.50cm.

Planting material and manure collection
Green finger F1 (variety) of okra was used as experimental planting material.The seed was collected from the seed shop (Maruf Beez Bhander) at Sonapur in Noakhali District.Vermicompost was collected from the local market at Sonapur in Noakhali District.

Land preparation
The land was ploughed by power tiller and left exposed to the sun for a week.After one week the land was harrowed, ploughed and cross-ploughed several times followed by laddering to obtain until good tilth.The corners of the field were spaded, and weeds and stubbles were cleared.To minimize water logging due to rainfall during the research period, drainage canals were built around the area, and the site was ultimately prepared five days before seed sowing.
Vermicompost was applied during final land preparation as basal dose.

Seed sowing
Seeds were sown during kharif-1 season following line sowing method and seeds are sown on 16 March 2022.Before sowing, seeds are mixed with ash so that seeds placed in the field uniformly.After 7 DAS seeds were germinated at a uniform level.

Intercultural operations
The seedlings were kept under close observation and necessary intercultural operations were done through the cropping season for proper growth and development of the plant.Five to six days after germination only healthy seedling was kept to grow in each location and other seedling were removed.Dead, injured and weak seedlings were replaced by new vigour seedling from the stock kept on the border line of the experiment.Weeding was done three times in plots to keep plots free from weeds.Irrigations were given by hand sprayer when needed.For insect and fungal control, imidacloprid and mancozeb were administered three times.Green pods were harvested at 3 days interval when they attained edible stage (i.e. the tender young pods of 8-13 cm long).Green pod harvesting was started from 7 May and was continued up to 10 July.

Data collection
Data on plant height, days for first flowering, number of fruits per plant, fruit length, fruit diameter, fruit weight, fruit weight per plant, yield per plot and yield per hectare of okra were recorded from six plants being randomly selected from each plot.

Statistical analysis
The recorded data of different parameters in this study were analyzed statistically by using Microsoft excel and statistix 10 statistical software package to find out the significance of the differences among the treatments.All obtained data were analyzed by following Gomez and Gomez (1984).

Plant height
Height of okra plants were significantly (P<0.01)influenced by the application of vermicompost (Figure 1).The highest plant height (100.43 cm) was recorded in treatment T3 (Vermicompost 20 t ha -1 ) followed by treatment T2 (88.23 cm), T1 (78.47 cm), and T0 (65.57cm), respectively.This result showed that the application of vermicompost 20 t ha -1 gave the highest plant height of okra.Similar results were found that organic fertilizer improved plant height of okra (Kota et al., 2022;Bhandari et al., 2019).

Number of fruits per plant
Application of different doses of vermicompost showed statistically significant (P<0.01)variation on the number of fruits per plant of okra (Figure 3).The maximum number of fruits per plant (22.13) was recorded in T3 (Vermicompost 20 t ha -1 ) followed by T2 (Vermicompost 15 t ha -1 ) which was (18.33).While the minimum number of fruits per plant was highest mean number of fruits per plant of okra.Similar result was claimed that application organic fertilizer produced significantly increased number of fruits per plant of okra (Kota et al., 2022;Bhandari et al., 2019).), T2 (Vermicompost 15 t ha -1 ) and T3 (Vermicompost 20 t ha -1 )

Fruit length
Statistically significant (P<0.01)variation was recorded on fruit length of okra for different levels of vermicompost management practices (Figure 4).The longest fruit (13.60 cm) of cucumber was measured in T3 (Vermicompost 20 t ha -1 ), and the lowest fruit (8.77 cm) was recorded in the treatment T0 (Control) followed by the treatment T1 (11.40 cm), and T2 (12.47 cm), respectively.This result showed that the application of vermicompost 20 t ha -1 gave longest fruit of okra.

Fruit weight
Fruit weight of okra was significantly (P<0.01)varied by the application of different levels of vermicompost (Figure 6).The maximum weight of fruit (13.47 g) was observed in treatment T3 (Vermicompost 20 t ha  ) and T3 (Vermicompost 20 t ha -1 )

Fruit weight per plant
Fruit weight per plant of okra was significantly (p<0.01)influenced by the application of vermicompost (Figure 7).The highest fruit weight per plant of okra (198.02g) was recorded from T3 (Vermicompost 20 t ha -1 ) and the lowest fruit weight per plant of okra (87.03 g) was recorded from T0 (Control).This result showed that the application of vermicompost 20 t ha  ), T2 (Vermicompost 15 t ha -1 ) and T3 (Vermicompost 20 t ha -1 )

Yield per plot
Yield per plot of okra showed significant variation due to the application of vermicompost (Figure 8).The maximum yield per plot (1.78 kg) was recorded from T3 (Vermicompost 20 t ha -1 ), while minimum yield per plot (0.79 kg) was recorded from T0 (control).This result showed that the application of vermicompost 20 t ha -1 gave maximum yield per plot.), T2 (Vermicompost 15 t ha -1 ) and T3 (Vermicompost 20 t ha -1 ) Yield per hectare Significant variation was recorded on yield per hectare of okra due to the application of different levels of vermicompost (Figure 9).The maximum yield per hectare of okra (17.83 t ha -1 ) was recorded from T3 (Vermicompost 20 t ha -1 ), while minimum yield per plant (7.88 t ha -1 ) was recorded from T0 (control).This result showed that the application of vermicompost 20 t ha -1 gave maximum yield per hectare.These results were in close conformity with the findings of Kota  ), T2 (Vermicompost 15 t ha -1 ) and T3 (Vermicompost 20 t ha -1 )

CONCLUSION
The results indicated that application vermicompost had a positive impact on the growth and yield parameters of okra.The current investigation's comparative results of many parameters evaluated showed that T3 was the best treatment because the maximum plant height of okra (100.43 cm), number of fruits per plant (22.13), fruit length (13.6o cm), fruit diameter ((2.01 cm), fruit weight (13.47 g), fruit weight per plant (198.02g), yield per plot (1.78 kg) yield per hectare (17.8 t ha -1 ) were found in treatment T3 (Vermicompost 20 t ha -1 ).Observing the results, it can be stated that application of vermicompost @ 20 ton ha -1 ) for okra cultivation gave better growth and yield in the coastal region of Bangladesh.

ACKNOWLEDGEMENT
The authors would like to thank the Department of Agriculture at Noakhali Science and Technology University for providing logistical help for this study.

Figure 3 .
Figure 3. Effects of vermicompost on number of fruits per plant of okra

Figure 4 .
Figure 4. Effects of vermicompost on fruit length of okra

Figure 5 .
Figure 5. Effects of vermicompost on fruit diameter of okra

- 1 )
followed by treatment T2 (11.43 g), T1 (9.31 g) where the minimum weight of fruit (7.48 g) was obtained from the treatment T0 (Control).This result showed that the application of vermicompost 20 t ha -1 gave maximum fruit weight of okra.Similar results had also been reported byKota et al. (2022).

- 1 gave
maximum fruit weight per plant of okra.These results were supported by the findings of Kota et al. (2022).

Figure 7 .
Figure 7. Effects of vermicompost on fruit weight per plant of okra

Figure 9 .
Figure 9. Effects of vermicompost on yield per hectare of okra