Effect of Sowing Dates and Nitrogen Levels on Population of Okra Jassids (Amrasca biguttula biguttula Ishida)

Okra (Abelmoschus esculentus L. (Moench) is one of the most important vegetable crops grown in Nepal. The crop is susceptible to various insect pests of which jassids (Amrasca biguttula biguttula Ishida.) is most predominant which reduces production and deteriorates seed quality of okra. A field study was conducted at Horticulture Farm, Agriculture and Forestry University, Rampur, Chitwan, Nepal to elucidate the effect of sowing date and nitrogen levels on the population and damage of jassids from April to September 2018. Three levels of nitrogen (100, 200 and 300 kg N ha-1) and five sowing dates (8th April, 20th April, 2nd May, 14th May and 26th May, 2018) were evaluated in randomized complete block design with three replications. Results indicated that the highest damage score was recorded in okra which was sown on 8th April (2.39) followed by 20th April (2.31) and 2nd May (1.26). The highest damage score of jassids was obtained with the use of nitrogen at the rate of 200 kg ha-1 (1.94) followed by 300 kg/ha (1.72) and 100 kg ha-1 (1.54). Mean population of jassids was maximum with okra sown on 20th April (29.91) and minimum with okra sown on 26th May (6.95). This study showed that late planting i.e. 26th May and applying low level of nitrogen i.e. 100 kg N ha- 1is an effective approach for reducing the jassids population and its damage in okra

Efficacy of commercial insecticides for cowpea pod borer (Maruca vitrata F.) management in Pokhara, Nepal

Cowpea (Vigna unguiculata Walp.) is a major grain legume used as vegetables and pulses. Among the several insect pest of cowpea, spotted pod borer is one of the most destructive pest. To evaluate the available chemical pesticides for pod borer management, a set of field experiments on cowpea variety Malepatan-1 were conducted at Horticulture Research Station, Malepatan, Pokhara in years 2019 and 2020. The experiments were laid out in Completely Randomized Block Design (RCBD) having seven  treatments viz.Flubendiamide 39.35 % SC @ 0.3 mL/L, Chlorantraniliprole 18.5 % SC @ 0.2 mL/L, Emamectin benzoate 5 % SG @0.3 g/L, Spinosad 45 % SC @0.3 mL/L, Bacillus thuringiensis Kurstaki @2g/L, Azadirechtin 0.03%@ 5mL/L and Control with four replications. Flubendiamide 39.35 % SC @ 0.3 mL/L and Emamectin benzoate 5 % SG @0.3 g/L were found the most effective insecticides in lowering cowpea flower and pod damage with highest benefit cost ratio; however, considering environment, Chlorantraniliprole 18.5 % SC @ 0.2 mL/L and Spinosad 45 % SC @0.3 mL/L being next effective treatments could be viable option to manage spotted pod borer in cowpea production.  &nbsp

Effect of intercropping on the incidence of Jassid (Amrasca biguttula biguttula Ish.) and Whitefly (Bemesia tabaci Guen.) in Okra (Abelmoschus esculentus L. Moench)

Okra is one of the most important summer vegetables in South Asian countries including Nepal. However, the damage by insects like Jassid (Amrasca biguttula Ish.) and whitefly (Bemisia tabaci Guen) has resulted in significant reduction of its production. An experiment was conducted based on intercropping taking okra (Abelmoschus exculentus L. Moench) as the main crop in Arghau, Lekhnath-27, Kaski, Nepal from March 4 to May 24, 2018. The intercrops used were coriander (Corriander sativum), carrot (Daucas carota), fennel (Foeniculum vulgare) and parsley (Petroselinum crispum). The population of jassid and whitefly was recorded from three leaves representing the different strata (bottom, middle and top) of the vegetative parts; and related yield parameters were also observed to correlate with the level of population incidence of these pests. Least numbers of jassids (5.50±0.29, 6.94±0.43, 8.00±0.41 and 3.69±0.76) were observed respectively at 30, 40, 50 and 60 days after sowing (DAS) in okra+ coriander. Likewise, okra + coriander intercropping was effective in inhibiting the population of whitefly (7.50±0.59, 8.56±0.19, 10.25±0.66 and 7.06±0.42) at 30, 40, 50 and 60 days after sowing (DAS) respectively. In contrary, the highest number of jassids and whiteflies were observed in okra + parsley and control (okra only). Both pod length (cm) and yield (t/ha) were the highest (17.92±0.57 and 28.20±0.49 respectively) in okra + coriander and were the lowest (16.42±0.21 and 27.58±0.39 respectively) in okra + carrot. The benefit-cost ratio was in order okra + coriander > okra + carrot > okra + fennel > okra + parsley > control (okra only). Among the different intercrop combinations, the okra + coriander was found most effective that could be suggested as one of the alternative strategies to limit the population of pests; jassid and whitefly in okra

Effects of different mulches and net house on crucifer aphid (Brevicoryne brassicae L.) population, growth and yield of broadleaf mustard (Brassica juncea)

Crucifer aphid, Brevicoryne brassicae, is a key pest of broadleaf mustard and other crucifers. An alternative integrated management approaches are recommended to keep the pest below economic threshold level. A field experiment was carried out to evaluate the effect of mulching and net house on aphid population, growth and yield of broadleaf mustard. Experiment was carried out in randomized complete block design with four replications from September to December 2016 at Rampur, Chitwan, Nepal. Five treatments used in experiment was untreated control, black plastic mulch only, reflective plastic mulch only, black plastic mulch plus imidacloprid 70 WSG @ 0.13gm/liter, and net house plus black plastic mulch. The results showed that the lowest population of crucifer aphid was recorded inside the net house with black plastic mulch and black plastic mulch with imidaclorpid 70 WSG @ 0.13g/L spray. Reflective plastic mulch was superior as compared to black plastic mulch and control to reduce the aphid population. Similarly, the highest yield (26.86t/ha) was obtained inside the net house with black plastic mulch followed by black plastic mulch with imidacloprid spray (25.99 t/ha). But the benefit-cost ratio was the highest (4.09) in black plastic mulch with imidacloprid spray followed by reflective plastic mulch (3.42), black plastic mulch (3.32), and net house with black plastic mulch (3.10). Benefit-cost ratio was lower in net house with black plastic mulch but products are safe from toxins and potentially profitable in long run. Considering its ecological cost, the use of pest exclusion net is recommended as a viable option for controlling insect pests of broadleaf mustard

Modified atmosphere packaging of capsicum for extending shelf life under coolbot condition

Capsicum is one of the high value vegetable crops in Nepal. Its demand in kitchen is increasing due to urbanization and increased awareness on its health benefit. Its commercial cultivation has been started in protected as well as open field conditions. It fetches higher price in market but has very short storage life under ordinary storage condition. An experiment was carried out to evaluate the modified atmosphere packaging (MAP) on extension of shelf-life of capsicum fruit. Fruit were harvested at full mature stage with smooth and shiny appearance from farmer's field grown under protected condition at Chitwan, Nepal. The fruits were brought to postharvest laboratory of National Horticulture Research Centre, pre-cooled for 3-4 hours, cleaned with muslin cloth and packed in 25 micron Low Density Polyethylene (LDPE) packaging with different number of pinhole sized perforations viz. without pinholes, eight pinholes, sixteen pinholes, twenty four pinholes and control (without MAP). The study was conducted in completely randomized block design with five treatments and four replications. Fruits were kept at coolbot storage (9.8+2 ºC, 86+5% RH) till 30 days and analyzed for various postharvest physical, chemical and physiological parameters at every 10, 20 and 30 days of storage. The result showed that LDPE packaging influenced on reduction of physiological loss in weight (PLW), spoilage loss, ascorbic acid content, TA, freshness, firmness and shelf life. The modified atmosphere packaging (MAP) without pinholes showed the minimum PWL (1.71%) and the optimum fruit freshness (4.76) but the spoilage loss was the maximum (14%). Among the packaging, MAP with 8 pinholes maintained majority of postharvest quality retention with reduced physiological loss in weight (4.15 %), freshness (4.5) and spoilage loss (2%)

Effect of Sowing Dates and Nitrogen Levels on Population of Okra Jassids (Amrasca biguttula biguttula Ishida)

Okra (Abelmoschus esculentus L. (Moench) is one of the most important vegetable crops grown in Nepal. The crop is susceptible to various insect pests of which jassids (Amrasca biguttula biguttula Ishida.) is most predominant which reduces production and deteriorates seed quality of okra. A field study was conducted at Horticulture Farm, Agriculture and Forestry University, Rampur, Chitwan, Nepal to elucidate the effect of sowing date and nitrogen levels on the population and damage of jassids from April to September 2018. Three levels of nitrogen (100, 200 and 300 kg N ha-1) and five sowing dates (8th April, 20th April, 2nd May, 14th May and 26th May, 2018) were evaluated in randomized complete block design with three replications. Results indicated that the highest damage score was recorded in okra which was sown on 8th April (2.39) followed by 20th April (2.31) and 2nd May (1.26). The highest damage score of jassids was obtained with the use of nitrogen at the rate of 200 kg ha-1 (1.94) followed by 300 kg/ha (1.72) and 100 kg ha-1 (1.54). Mean population of jassids was maximum with okra sown on 20th April (29.91) and minimum with okra sown on 26th May (6.95). This study showed that late planting i.e. 26th May and applying low level of nitrogen i.e. 100 kg N ha- 1is an effective approach for reducing the jassids population and its damage in okra

Profitability, marketing, and resource use efficiency of ginger production in Rukum west, Nepal

The study was designed to investigate the profitability, marketing, and resource use efficiency of ginger production in Rukum west. The sample size of 62 ginger-growing farmers out of 187 farmers was determined using slovin’s formula. In addition, 20 traders from two major market hubs Simrutu and Jhulneta were interviewed. The pre-tested semi-structured interview schedule was administered to interview a randomly selected sample size. Data were analyzed using descriptive and statistical tools, including the Cobb-Douglas production function. Result showed that the average area under ginger cultivation was 0.14 ha. A major portion (46.56%) of the cost was found to be incurred by the seed alone in ginger cultivation. The benefit-cost ratio (2.02) indicates that ginger production enterprise was profitable. The productivity of ginger in the study area was estimated to be 11.39 Mt/ha, while per kg cost of production was found to be (NRs 35.67 = USD 0.30). Most of the gross income (78.85%) was found to be contributed by fresh ginger. Similarly, gross margin, market margin, and producer’s share were found to be 21.16, 33.33, and 62.97%, respectively, for 1 kg of ginger. The indexing technique identified high-cost with low-quality seed and price instability as the major problems associated with the production and marketing of ginger, respectively. Cobb-Douglas production function estimated the value of return to scale at 0.889, implying that ginger production exhibited decreasing returns to scale. A study on resource allocative efficiency revealed that farm yard manure and total labor were underutilized resources while seed rhizome was overutilized resource. Thus, for optimal allocation of resources, expenditure on farm yard manure and total labor need to be increased by 87.374% and 39.908%, respectively. The study concluded that an effort should be made to bridge the gap between optimal resource utilization and current practices. For this, it is prime important to interconnect the combined efforts of ginger growers, provincial government, or any developing partners

Farmers’ Knowledge on Pesticide Safety and Pest Management Practices: A Case Study of Vegetable Growers in Chitwan, Nepal

Farmers’ knowledge on pesticides and their safe use are critical for implementing effective pest management program. A household survey was conducted using the semi-structured questionnaire to evaluate vegetable growers’ knowledge on pesticide safety and pest management practices in Nepal. Results indicated that chemical pesticides were the primary choice of over 80% growers for pest management. Notably, 90% growers were aware of adverse effects of pesticides on human health and to the environment. Over 84% growers used at least one form of personal protection equipment (PPE) during pesticide spray or handling, although the quality and appropriateness of the PPE warrants further investigation. Nearly 17% growers received at least one short-term training on integrated pest management (IPM); however, all of them neither knew the harmful effects of pesticide residues nor practiced proper pesticide disposal methods. Over 90% of growers rely on local pesticide retailers (i.e., Agro-vets) for technical know-how about pesticide selection, handling, and use. This study highlighted a need for immediate implementation of strict pesticide use regulations and recommended educational programs for pest control professionals, growers, and pesticide retailers