Journal of Agriculture and Forestry University

Biology and management of Chinese citrus fly, Bactrocera minax (Enderlein) (Diptera: Tephritidae)

D. Adhikari — 2022-12-16

The Chinese citrus fly, Bactrocera minax (Enderlein) (Diptera: Tephritidae) is an important insect pest of citrus species which causes significant fruit damage in Nepal, India, Bhutan and China. An attempt has been made to review the biological aspects and management measures of this pest compiling published literatures in the national and international journals, proceedings, reports, newsletter and books. This review highlights the findings on the nomenclature, morphology, distribution, biology of the Chinese citrus fly and provides potential prospect of pest management measures, which are useful to the researchers, policy - makers, citrus growers and extension workers.

Analysis of floor price trend of raw coffee in Nepal

G. Luitel — 2022-12-16

Nepalese coffee industry has passed a long way of production, processing and marketing. Coffee as a high value crop with floor price helped farmers to sustain their production. This study reviews the historic approaches of floor price fixation system and its trend using secondary data of National Tea and Coffee Development Board (NTCDB). The floor prices were averaged and converted into Green Bean Equivalent (GBE) units and analysed in different time zones. It was found that the floor price fixation system has been changing over years. The floor price was roughly based on transportation cost in earlier years. Grading-based price fixation of fresh cherry came into practice during 2002/03-2005/06. Eventually, more precise and practicable floor price measures were introduced for different quality grades, which was practiced for almost a decade from 2006/07 to 2014/15. Starting from 2015/16, previous approach was slightly modified based on organic certification which is still in practice. Moreover, it was found that the price of raw coffee has increased notably over years. While the price index of raw coffee in 1994/95 was merely 26.37, it has increased by more than nine times to 243.12 in 2021/22. Since higher priced raw coffee will not make it competitive in the global market, the floor price should be adjusted based on international market trend, considering macroeconomic parameters as well.

Host plant preference by the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Noctuidae: Lepidoptera) on the range of potential host plant species

S. Tiwari — 2022-12-16

Maize is the most important cereal crop after rice and wheat in Asia. Nowadays, maize production is threatened by one invasive pest, the fall armyworm (Spodoptera frugiperda) particularly in Africa and Asia, and threatens millions of poor people. Fall armyworm feeds a wide range of crops and non-crops including weeds, with over 353 plant species. But most frequently consumed crops are field corn, sweet corn, wheat, sorghum, sugarcane, Bermuda grass etc. Fall armyworm has six larval stages, the first three stages are less voracious compared to the latter stages. Larvae are very numerous and disperse in large numbers and behave like ‘armyworm’. Insecticides are considered an important tool of FAW management as well as other lepidopteran maize pests. However, these practices are not sustainable and are linked to the environment, biodiversity and farmers' health. Alternative management strategies should be developed by understanding pest biology and ecology. Hence, a series of laboratory choice and paired-choice tests were conducted at Agriculture and Forestry University in May 2021 to evaluate the host plant preference by the fall armyworm. Potential host plants were Zea mays (maize cultivars - Rampur composite, Arun-2 and Rampur hybrid-10), Pennisetum purpureus (Napier), Oryza sativa (rice), Sorghum bicolor (Sorghum), Fagopyrum esculentum (Buckwheat), Vigna unguiculata (Cowpea) and Glycine max (Soybean). In choice tests, FAW preference was ranked as Rampur Composite > Sorghum > Rampur hybrid-10 > Arun-2 > Napier > Rice > Buckwheat > Cowpea > Soybean. Rampur composite and sorghum were the most preferred host plants, Rampur hybrid, Arun-2 and Napier were the medium preferred, rice was categorized as the low preferred and other host plants such as buckwheat, cowpea and soybean were the least preferred host plant of fall armyworm. In paired-choice tests, Rampur composite was more preferred than sorghum, but not significantly so. These research findings are useful to utilize in habitat manipulation strategies for fall armyworm management. Most preferred plant species can be deployed as trap crops and least preferred host plants can be used as repellent or push crops in a push-pull strategy. Such host plants in-and-around the main field can reduce the fall armyworm damage and reduce pesticide amount in main crops.

Evaluation of Kangkong (Ipomoea aquatic L.) genotype, a potential green leafy vegetable in summer season at Khajura, Banke, Nepal

S. Lohani — 2022-12-16

Kangkong (Ipomoea aquatica L.) belongs to the plant family Convolvulaceae. A set of varietal trial was conducted in Directorate of Agricultural Research Khajura, Banke, Nepal with three genotypes; HRDKAN001 (Combodian), HRDKAN002 (Thaipalungo as check variety) and HRDKAN003 (Bangladeshi); which were collected through National Horticulture Research Centre, Khumaltar. The objectives of this experiment were to select high yielding genotypes for green leaf production during summer season. The experiments were carried out in two consecutive years, April 2017 and 2018 and laid out in Randomized completely block design with seven replications in open field condition. The spacing was maintained 50 cm row to row and 30 cm within the row in each year. Plants were fertilized with 200:150:120 kg NPK and 20 tons farm-yard manure per hectare. Data were recorded on vegetative growth, disease response, vegetative yield, qualitative parameter and consumer’s preference. From the result of experiment, HRDKAN001 and HRDKAN002 were found to be higher yielding and showed good cooking quality and these genotypes were selected for the further evaluation at Khajura and similar agro-ecological conditions of Nepal.

Constraints on the use and adoption of information and communication technology (ICT) tools and farm machinery by paddy farmers in Nepal

U. P. Sigdel — 2022-12-16

Information and communication technology (ICT) tools such as radio, television, mobile phone, the internet and computers are gaining momentum in Nepal’s agriculture development discourse, filling void that traditional agriculture extension has failed to fill. Agricultural mechanization implies using various power sources and improved farm tools and equipment in agriculture. This study aims to determine the barriers while using ICT tools and agricultural machinery in Jhapa, Kapilbastu and Kailali districts of Nepal. Pretested semi-structured interview schedule was employed to collect data from 390 sample respondents selected randomly. Descriptive statistics and the appropriately developed scales were used in the data analysis. Moreover, respondents considered lack of awareness along with its requirement of skilled human resources and its cost were the primary reasons for the rejection of the use of ICT tools, where the overall rejection level was at a medium level. The constraints level of the use and adoption of farm machinery was found high; the significant constraints considered by the respondents were the high price of the machinery along with poor skills, knowledge, facilities, and poor maintenance service. The overall index value for the rejection of the use and adoption of farm machinery in paddy farming was at a moderate level. The respondents’ primary reasons for the rejection of the use of farm machinery were the high price of the farm machinery long with poor training, poor skilled human resources, and complex ideas to learn. Hence, to overcome to those factors, appropriate awareness campaigns and educational programs are necessary.

Determinants for adoption of foundation rice seed production: Evidence from Kailali district of Nepal

J. Dhungana — 2022-12-16

Rice seed production is an emerging agricultural enterprise to increase the income of farmers in Kailali. However, adoption of seed production technology is very limited in spite of its potential, which results in the poor supply of quality seed for its multiplication. Thus, this paper examines the influencing factors affecting farmers’ decision to adopt the foundation rice seed production in Kailali, Nepal. In total 158 households, 116 certified, and 42 foundation seed producers were selected using a stratified random sampling technique. The primary data were collected from September to November 2021. T-test, chi-square, and binary logistic model were applied for data analysis using SPSS. The result revealed that land size, experience, gender of household head, access to credit, training, extension contact, and type of family are statistically significant between two categories. Besides, the empirical result of logistic regression analysis indicated that out of twelve, six explanatory variables such as age, experience, training, extension contact, education, and type of family had significantly influence on adoption decision. Therefore, it is concluded the rice seed training programs and increasing the extension services would be beneficial to motivate the farmers for the production of foundation rice seed production.

Effect of foliar application of different nutrients on growth, yield, and quality of potato (Solanum tuberosum L.) in Sankhu, Kathmandu, Nepal

A. Duwadi — 2022-12-16

A study was conducted from January to June 2021 in the farmer’s field at Shankharapur-7, Sankhu, Kathmandu, Nepal to assess the effectiveness of the foliar application of different nutrients for potato production. The field experiment was laid out in Randomized Complete Block Design with six treatments, T₁: zinc at 560 ppm, T₂: magnesium at 0.4 %, T₃: boron at 100 ppm, T₄: calcium at 0.8 %, T₅: copper at 1 %, and T₆: control and were replicated four times. The chemicals were sprayed 30 and 40 days after planting until runoff. The highest tuber yield was obtained with the application of calcium at 0.8 % (38.57 Mtha^-1) while the lowest marketable tuber yield was obtained with copper at 1 %. The highest calcium and zinc content in potato tuber was observed with the application of calcium at 0.8 % and zinc at 560 ppm respectively. Likewise, the application of zinc increased the protein percentage in tuber by 23 % compared to the control. Thus, it can be concluded that the foliar application of calcium at 0.8 % is the most economical resulting in the highest plant growth, yield, and producing the best quality potatoes under the climatic condition of Sankhu, Nepal.

Evaluation of reproductive performance and litter traits of Khari, Jamunapari and Sirohi crossbred goats in Surkhet district of Karnali province, Nepal

N. Bhattarai — 2022-12-16

Goat produces 20.36% of meat, ranking in second position after buffalo meat production in Nepal and contributes 4% in agriculture GDP. Making out the influence of non-genetic factors on the phenotypic expression of reproductive and litter traits of goat is important to develop selection/evaluation criteria with healthier precision. Khari, Jamunapari and Sirohi crosses were considered for the comparative study of their reproductive and litter traits. Data obtained from the study of different reproductive and litter traits were firstly entered into the computer via excel package programs. The data were analyzed by Mixed Model Least-square and Maximum Likelihood Computer Program PC-2statistical package developed by Walter R. Harvey and the means were compared by Duncan’s Multiple Range Test (DMRT). Results revealed that the pooled means for AFC, AFK, PPE, GL, and KI were 344.31, 493.69, 173.42, 148.93, 319.58 days respectively. Similarly, pooled means for LSB, LWB, LSW, and LWW were 1.43, 5.16 kg, 1.37 and 28 kg respectively. Production system and breed were important nongenetic factor affecting reproductive traits significantly whereas parity is the most important non genetic factor affecting litter traits of goat. Almost all of the reproductive traits (except PPE) were observed better under the grazing system in Khari breed. Winter kidding goat had better PPE. Likewise, all the litter traits were significantly better in later parities with almost similar performance in all the breeds. To summarize, Khari was explored as a high potential goat regarding its reproductive traits with a massive scope of improvement in its litter weight trait through effective selection measures within the population.

Response of cucumber (Cucumis sativus L. Cv. Bhaktapur local) to the application of plant growth regulators in plastic tunnel

K. Dahal — 2022-12-16

The field experiment was conducted to know the yield performance of cucumber var. Bhaktapur Local with the application of plant growth regulators (PGRs) in the farmers’ field of Lamjung, Nepal during September to November, 2013. Five treatments (Four PGRs; NAA @10 ppm, GA₃ @ 50ppm, GA₃@100ppm, MH@ 60ppm and distilled water as control) were replicated six times under walk-in plastic tunnel. The experiment was laid out in randomized complete block design. The first 30 flowers of each plant were used for the observation. PGRs were sprayed in 2-4 true leaf stage of seedling, 20 days after first spray and 10 days after second spray. The research revealed that NAA @ 10 ppm had higher effect in sex expression, fruit set and yield than rest of the treatments. GA₃ @ 100 ppm had significantly higher number of male flowers and more vine growth than other treatments. Branch per plant was obtained as the highest with MH @60 ppm followed by NAA @10 ppm. The marketable fruit yield was significant with NAA @10 ppm followed by MH@ 60 ppm, GA₃ @50 ppm, GA₃ @100 ppm than control. It is concluded that thermo-sensitive variety of cucumber Bhaktapur Local can be grown with the use of plant growth regulators particularly, NAA@ 10 ppm, under walk-in plastic tunnels during the autumn-winter season in the mid hills of Nepal. The research further indicated that cucumber can be a profitable and a potential agriculture enterprise for the area.

Aphid Pest Management in Sweet Pepper Field with Rapeseed as a Companion Crop

A. Shrestha — 2022-12-16

Sweet pepper, Capsicum annum L. is commercially grown vegetable grown for its nutritional and economical value. Sucking pests like aphids, whiteflies, thrips, mites, etc. are the major insect pest in sweet pepper fields. Farmers deliberately have been using chemical pesticides in their crop to manage various insect pest and such practices of using hazardous chemicals are harmful to human health and the biodiversity. Similarly, farmers don't have an idea of planting trap and/or companion plants and its role in natural control of pest. Hence, a study was conducted to know the population dynamics, especially to assess the aphid (Myzus persicae, Sulzer) population and its potential natural enemies by planting rapeseed as companion crop. This field experiment was conducted in six different locations of Bharatpur-23, Chitwan from Nov 2019 to Jan 2020 where three plots of sweet pepper were planted with rapeseed as companion crop and other three plots solely having no floral source around. Aphid population was recorded at weekly interval and its major natural enemies; ladybird beetle and syrphid fly. Abnormal data were squared root transformed and analyzed by using paired sample t-test. The result showed that the aphid population in sweet pepper field with companion crop was significantly lower than in sweet pepper grown without floral source (control). Highly significant number of ladybird beetles and syrphid flies were recorded in sweet pepper with companion crop compared to control. The finding is helpful to develop an integrated management protocol of sweet pepper pests with the practice of following conservation biological control strategy.

Efficacy of biological and chemical insecticides against diamondback moth (Plutella xylostella L.) on Cabbage (Brassica oleracea L. Var capitata)

B. Sapkota — 2022-12-16

Diamondback moth, Plutella xylostella (L.) is the most devastating pest in late winter in cabbage (Brassica oleracea var. capitata L.). Pesticides are the common pest management practices to manage the crucifer pests. These practices are not sustainable and ecofriendly. Hence, a field experiment was conducted to evaluate the efficacy of chemical, botanicals and biological insecticides to develop safer and more effective insecticides for the diamondback moth, in cabbage during winter season 2018-19. The experiment was laid in a randomized block design (RCBD) with four replication and five treatments viz. i) Emamectin benzoate 5SG @ 0.4 gm/l, ii) Neemix (Azadirachtin 300 ppm) @ 2 ml/l, iii) Metarhizium anisopliae @ 2 ml/l, iv) Beauveri abassiana @ 2 ml/l and v) control (untreated). Standard recommended agronomic practices were followed in field to ensure better crop growth. The maximum reduction of P. xylostella larval population over untreated control was recorded in Emamectin benzoate 5 SG (95%) and Neemix (95%) sprayed field. Bio-pesticides such as M. anisopliae and B. bassiana were effective only after the first spray with maximum efficacy of (76%) and (65%), respectively, and decreased efficacy in the second and third sprays. Both yields with the least number of damaged leaves and maximum net profit was recorded in Emamectin benzoate sprayed plots with a higher benefit-cost ratio of (3.47), which was followed by M. anisopliae (2.96) and Neemix (2.92) treatments, respectively. Emamectin benzoate 5 SG and Neemix are effective and safe insecticides in controlling diamondback moth in cabbage crops and are viable options for integrated management of P. xylostella.

Comparative study on fattening performance of different goat breeds supplemented with common fodder trees in mid hills of Nepal

S. H. Ghimire — 2022-12-16

Goat (Capra hircus) is important meat animal of the country. Fattening performance of different breeds of goats with common mid hill fodder trees was conducted in Completely Randomized Design with 4×5 factorial arrangements at Goat Research Station, Tanahun. The first factor was breed of goats and second factor was species of fodder trees. The main parameters monitored included dry matter (DM) intake, fattening performance and average daily gain (ADG) of goats with respect to different fodders. Results showed that DM intake by breeds of goats and species of fodder trees were highly significant (p<0.001). Weight gain of different breed of goats and species of fodder trees were significantly different (p<0.01) with Boer cross and Listea monopetala having higher weight. The ADG of Boer cross, Jamunapari cross, Khari and Barbari cross were 70.93g, 59.35g, 53.38g and 45.36g, respectively and highly significant (p<0.01). Likewise, ADG of L. monopetala, was higher than other fodder trees. The interaction effects of breeds of goat and fodder species on ADG were similar up to 8 weeks and later observed significantly different (p<0.01). L. monopetala and Ficus lacor were better fodders in terms of fattening performance of different breeds of male goats. From the experiment of blood serum analysis, phosphorus content of F. lacor was significantly higher (p<0.01). Results of subsequent short term intake rate (STIR) measurement in order to find out the preference of fodders trees revealed that significantly higher (p<0.05) intake was obtained for L. monopetala, followed by F. lacor, Ficus glaberrima, Melia azedarach and mixed fodders (0.45g, 0.39g, 0.38g, 0.34g and 0.33g DM min¹ per kg metabolic body size), respectively. The results of this study revealed that Boer crosses were more potential for fattening in terms of weight gain and voluntary intake. Likewise, L. monopetala and F. lacor were found better in fattening the male goats compared to other fodders.

Distribution of isoflavone and pinitol content in different parts of Serica lespedeza

K. H. Dhakal — 2022-12-16

Isoflavone is an important functional component that is associated with human health benefits such as the decreased risk of heart disease, menopausal symptoms, cardiovascular disease, and bone resorption as well as breast, prostate, and colon cancers. Pinitol (also referred to as D-Pinitol) is a type of sugar and classified as a chiro-inositol (sugar alcohol), has been demonstrated to exert insulin-like, anti-inflammatory and a hypoglycemic effect (to reduce blood sugar level). Sericea lespedeza (Lespedeza cuneata) species were collected from the different parts of Korea in the autumn season of 2011 and analyzed the isoflavone and pinitol content of leaves and stems by High-Performance Liquid Chromatography (HPLC). A large variation of isoflavone and pinitol content in the leaves and stems of lespedeza species was observed. The average isoflavone content of leaves and stems were 1,612 and 873 μg/g and ranged from 44 ~ 6,536 and 25 ~ 3,666 μg/g, respectively. Similarly, the average pinitol content of leaves and stems were 15,195 and 9,104 μg/g and ranged from 5,049 ~ 35,289 and 1284 ~ 27,185 μg/g, respectively. Both isoflavone and pinitol content in the leaves were significantly higher than in the stems. Leaves of sericea lespedeza showed unexpectedly higher isoflavone and pinitol. The average isoflavone content in leaves and stems among nine provinces were also significantly different. The highest isoflavone content in leaves (6,536 μg/g) and stems (3,666 μg/g) were measured in the samples collected from Chungcheongnam and Gangwon provinces, respectively. Similarly, the highest pinitol content in the leaves (35,289 μg/g) and stems (27,185 μg/g) were measured in the samples collected from Gyeonggi and Gangwon provinces, respectively. The genotypes with high isoflavone and pinitol content especially in the leaves of this medicinal herb could be used as elite genetic resources for food industries to make quality functional food products as well as medicines especially for diabetes.

Maize cultivation: present status, major constraints and farmer's perception at Madichaur, Rolpa

S. Dhakal — 2022-12-16

Maize (Zea mays) has been one of the most popularly grown crops in the mid hills of Nepal. With a view of assessing the present agronomic management and constraints of maize cultivation, a field survey was carried out in the summer of 2020 at Madichaur, Rolpa, Nepal. Simple random sampling procedure was used to collect data from 100 respondents using a semi structured interview schedule. Information regarding the productivity and adoption of improved technologies by maize growing farmers were also collected. The data were processed and analyzed using MS-Excel and SPSS. Results revealed maize-based cropping system as the major cropping system (65%) with rainy season maize being the dominant one (76%). Varietal selection was primarily based on the local prevalence whereas own preserved seeds were used by majority of the respondents. Local plough was the major tool for land preparation whereas majority of the respondent used FYM as nutrient source and followed sowing behind the plough. Gap filling, thinning, weeding, earthing up was quite common among the respondents, however their intensity varied. External cob storage was the common method of storage. Biotic stress was identified as the major bottleneck for increasing maize productivity followed by lack of irrigation and technical know how.

Laboratory bioassay of fall armyworm (Spodoptera frugiperda) larva using various insecticides

S. Sharma — 2022-12-16

Fall armyworm (FAW), Spodoptera frugiperda J.E. Smith, is a polyphagous invasive pest that seriously affects the maize crop. Various insecticides such as Spinosad, Chlorantraniliprole, Imidacloprid, Emamectin benzoate, Spinetoram and Neem-based insecticides are recommended to control this pest. However, their efficacy is not well studied in Nepal. Hence, a study was performed to evaluate the efficacy of the above-mentioned insecticides for FAW management in laboratory experiments. Seven different treatments (six insecticides such as Spinosad 45% SC, Chlorantraniliprole 18.5% SC, Imidacloprid 17.8% SL, Emamectin benzoate 5% SC, Spinetoram 11.7% SC, Neem-based pesticide (Azadirachtin 1500 ppm) and control (water spray) were evaluated in three replicated CRD design. Spinosad and Spinetoram were found effective for the FAW mortality in which > 50% mortality of the larva was obtained in twelve hours and > 90 % mortality in twenty-four hours. Likewise, Emamectin benzoate and Chlorantraniliprole also caused > 90% mortality within twenty-four hours. Azadirachtin and Imidacloprid were not as effective as other pesticides that caused only 17% larval mortality in the first twelve hours and 68% mortality in sixty hours. Similarly, Imidacloprid caused 8% larval mortality in twelve hours and 59% mortality in sixty hours. There was no mortality in water spray (control). This information gives an idea of all pesticides are not equally effective and efficient. Such information’s are important to the farmers to select the right insecticides for the control of FAW in maize crops.

Effectiveness of different measures to control red bloom in carp ponds

R. B. Mandal — 2022-12-16

Red blooms caused by Euglena sanguinea (Ehrenberg, 1832) might cause severe depletion of dissolved oxygen significantly in the pond. An experiment was conducted to assess the effects of measures for controlling E. sanguinea on water quality, growth and yield of carp polyculture. The experiment included four treatments: without mitigation measure (T1), skimming using net skimmer (T2), fertilization with urea and diammonium phosphate (T3) and liming using agriculture lime (T4) with three replications. The experiment was carried out for 120 days. The results showed that abundance of E. sanguinea was significantly lower (p < 0.05) in urea and diammonium phosphate treated ponds (270 ± 10 cells ^L-1) than control ponds (1650 ± 90 cells L^-1). Water quality parameter such as nitrite, total nitrogen and total phosphorus were significantly (p < 0.05) higher in control ponds (T1) than in treatment ponds. The net fish yield of rohu was significantly higher (0.19 ± 0.0 t ha^-1) in T3 ponds than T2 ponds (0.07 ± 0.0 t ha^-1). The present experiment effectively controlled abundance of E. sanguinea but admixture of urea and diammonium phosphate application appeared to be better control measures because dissolved oxygen content was at acceptable level in the ponds.

Determinants of technical efficiency among dairy farms in Chitwan, Nepal

S. C. Dhakal — 2022-12-16

Nepalese dairy sector has been showing structural changes with adoption of latest technologies like improved breeds, feeds, cultivated fodder and additives. In the context of these changes, this research was conducted to assess the technical efficiency and its determinants among dairy farms. The study was accomplished with primary data collected through face-to-face interview using semi-structured interview schedule from a sample of 240 dairy farms selected randomly using simple random sampling technique from 8 wards of Bharatpur Metropolitan City, Chitwan. Data were analyzed using descriptive statistics, stochastic production frontier and tobit regression model. Technical efficiency was found to be the highest in mix dairy farms (3.530) followed by cow farms (2.56) and buffalo farms (2.138). Labour was the most contributing factor in all three types of dairy farms. This study had shown that average annual income per farm should be Rs. 542000, Rs. 403225 and Rs. 611400 for getting 90% technical efficiency in milk production at buffalo, cow and mix farms, respectively. Similarly, 57% buffalo farms were operating at efficiency of 30-60%, 46% cow farms were operating at efficiency of 30%, and 67.5% mix farms were operating at efficiency of 30 to 60%. Total investment in dairy farming, training and adopting dairy as primary occupation were positively and significantly affecting technical efficiency on buffalo, cow and mix type of dairy farming system. There is still large scope to increase the annual milk production in the dairy farms of Chitwan through efficient use of available resources with the existing technologies. This is concluded that dairy farming system can be promoted efficiently by increasing total investment in dairy farming through easy access to loan, training on dairy animal production and management, ensuring dairy business as profitable primary occupation, promotion of fodder and pasture production, and securing easy access to medicines and additives.

Effects of varieties and fertilizer levels on yield and economics of hybrid rice at Hardinath, Nepal

U. Sah — 2022-12-16

Hybrid rice has the potential to increase rice yield. Fertilizer requirement is higher to achieve higher productivity in hybrid rice. A field experiment was carried out to evaluate the performance of hybrid rice varieties at different levels of fertilizer management. The experiment was conducted at research farm of National Rice Research Program (NRRP), Hardinath, Dhanusha, Nepal during rainy season of 2018. The experimental plot was laid out in a strip plot design with three replications. The treatment consisted of combination of six registered hybrid rice namely Arize 6444, Arize Tejgold, Gorakhnath 509, Shanti, Sudha, US 312 and two high yielding checks viz., Sabitri and Hardinath 1; and three levels of fertilizer management viz., Farmers practices ( 60-40-0 N, P₂O₅, k₂O kg ha^-1), National recommended Dose (100-30-30 N, P₂O₅, k₂O kg ha^-1) and 125% of National recommended Dose (125-40-40 N, P₂O₅, k₂O kg ha^-1). The result of research revealed that rice hybrid Sudha produced the highest grain yield (5659 kg ha^-1) followed by US 312 (5153 kg ha^-1). All the hybrids produced significantly higher yield than improved check varieties. The yield increment in rice hybrids ranged from 17.7 to 42.0% and 54.9 to 119.9% over Sabitri and Hardinath1 respectively. Higher gross return (Nrs 190.78 thousand ha^-1), net return (Nrs 100.77 thousand ha^-1) and benefit cost ratio of (2.11) was obtained in rice hybrid Sudha followed by US 312, Shanti and Arize Tejgold. Similarly, higher gross return (NRs. 178.59 thousand ha^-1), net return (84.59 thousand ha^-1) and benefit cost ratio (1.9) were found higher in 25% more fertilizer applied dose than National recommendation dose. Therefore, all tested hybrid rice can produce higher grain yield and 25% higher dose of fertilizer was better than national recommended dose for achieving higher yield and net income.

Effectiveness of crop and livestock protection methods against wildlife damage: A case from Chitwan National Park, Nepal

S. Ghimire — 2022-12-16

Human-wildlife conflict is a major issue for policymakers and conservationists due to economic loss to the communities living in the close territory of the park, affecting their livelihoods and wellbeing. This study aims at identifying and quantifying wildlife-induced damages on crops and livestock and methods used by communities for crop and livestock protection. A total of 434 households living in the vicinity of the park from the ten forest user groups around the Chitwan national parks and buffer zone were randomly sampled and interviewed with the use of semi-structured questionnaires in the year 2021. Findings revealed a total of 87.86% of rice-growing households reported the damage of rice whereas 90.32% and 87.68% of households reported the damage to wheat and maize, respectively. The annual loss of 78 kg of rice per household (NRs. 1776 at prevailing market rates) was reported along with the loss of wheat (86 Kg-worth of NRs. 2,523) and maize (96 Kg-worth of NRs. 2,019) per household. About 59% of households had lost at least a livestock species and poultry in last year, and that varied well across the sectors. Twelve different methods and techniques were identified by communities that were used regularly to prevent crop damage and livestock loss with the majority of people using certain methods and techniques against crop damage and livestock loss. A total of 425 (97.93%) were reported that they used at least one method and technique to prevent crop damage and livestock loss. Among all these methods, crop guarding, shouting, use of natural fences, guarding by dogs, and throwing stones were the most effective and safest practices/techniques, but the use of a single means and approach was found ineffective. This suggests the need for developing site-specific management techniques to minimize crop damage and livestock loss in the National Park vicinity and adjoining protected areas. Apart from the different mitigating means, construction, and maintaining permanent fences on the border of the national parks, there should be the provision of conservation education to communities bordering protected areas to practice sustainable agriculture and income-generating programs that are conservation-friendly. that may include, for example, provision of conservation educations along with income-generating programs that are conservation-friendly.

Growth performance of different fish species during dry period in Chitwan, Nepal

P. Neupane — 2022-12-16

In order to assess the growth and yield of different fish species during dry period, an experiment was conducted in the Aquaculture Farm of Agriculture and Forestry University, Rampur, Chitwan from 1 April to 10 July, 2021. The experiment included three treatments: T1 (Carp polyculture), T2 (Common carp Cyprinus carpio monoculture) and T3 (Nile tilapia Oreochromis niloticus monoculture), each with three replications. Silver carp (Hypophthalmichthys molitrix 7%), Bighead carp (Aristichthys nobilis 20%), Grass carp (Ctenopharyngodon idella 13%), Rohu (Labeo rohita 30%), Mrigal (Cirrhinus mrigala 10%) and Common carp (20%) were stocked at densities of 1,400, 4,000, 2,600, 4,000, 6,000 and 2,000 fish/ha, respectively. Stocking density of Common carp and Nile tilapia was 20,000 fish/ha. Fish were fed with sinking pellet (28% crude protein) at the rate of 3% of body weight. Gross and net fish yield was significantly higher in T3 (89.89±0.67 t/ha/yr,16±0.25 t/ha/ yr) than in T2 (4.88±0.38 t/ha/yr, 4.05±0.35 t/ha/yr) due to higher (p<0.05) survival in T3 (72.5±11.3 %) than in T2 (40.6±4.5 %). Gross margin was significantly higher in T3 (1,257,482±186,600 NRs./ha/yr) than in T2 (434,250±124,753 NRs./ha/yr). Based on higher survival, yield and gross margin, Nile tilapia monoculture is suitable for dry season.

Contribution of marginal land and indigenous crops on food security: A case of eastern Chitwan, Nepal

R. H. Timilsina — 2022-12-16

People have utilized indigenous and underutilized crops available in the marginal land for their food. However, little is known about the contribution of these crops to food security. To assess the contribution of these crops to food security of local people, a survey was done with 107 respondents selected from community forest users of the eastern Chitwan of Nepal in 2020. The findings revealed that fiddle head fern (Matteuccia struthiopteris L.), air potato (Dioscorea bulbifera L.), stinging nettle (Urtica dioica L.), and white yam (Dioscorea alata L.) were consumed mostly compared to other indigenous and underutilized crops. Community forest was a major source of underutilized crops followed by marginal land. Though air potato was available only for four months, its contribution to food security was higher than the other crops. Indigenous crops were found gradually disappearing due to producers' poor access to land to cultivate, misuse of land, and ineffective implementation of the Land Use Act. Further, local people’s engagement on off-farm employment had increased marginal land fallow. The study found that the prices of indigenous and underutilized crops offer income-generating opportunities. Thus, a marginal land use plan considering indigenous and underutilized crops is needed for both food security and income of local people.

Husbandry practice, health, productive and reproductive status of lulu cattle in Mustang, Nepal

G. Gautam — 2022-12-16

Lulu is the only indigenous cattle of taurine (Bos taurus) breed that is reared in northern part of central to western Nepal. There have been no recent studies on husbandry practice, health status, productive and reproductive performance of Lulu cattle in Nepal. Therefore, this study was conducted to know the husbandry practice, health, productive and reproductive status of Lulu cattle in Mustang district. Household survey was conducted in Lulu cattle rearing households (n=183) in Mustang; fecal sample of Lulu cow was collected from each household and examined for endoparasitic infection. Body condition score (BCS), hair coat, anemic and milk production status were recorded only from lactating cows (n=242). All of the respondents kept their cows in loose housing system. Among them, 90.2% grazed their cattle, 21.3% provided some cultivated pastures, 3.3% supplemented commercial feed and none of the farmers fed mineral supplementation to their cattle. All the milk produced was used only for home consumption. Only 22% of respondents dewormed their cattle regularly and 29% never dewormed; only 12% vaccinated against foot and mouth disease (FMD) every year and 25% never vaccinated. Cattle of 79.8% households had endoparasitic infection. Among 242 lactating cows, 13.2% cows had poor BCS (<2.75), 95.5% had rough hair coat and 20.4% had anemic (pale) eye mucous membrane. Total 8.3% cows had the history of abortion. Mean (±SD) peak milk yield and lactation length were 2.01±0.30 liter/day and 9.84±0.86 months, respectively. Most of the cows calved in summer (72%) followed by autumn (12%), spring (11%) and winter (5%). Mean (±SD) age of first calving, calving to conception interval, inter-calving interval, dry period and the number of services per conception were 36.0±0.48 months, 3.99±0.68 months, 12.97±1.34 months, 2.71±0.45 months, and 1.47±0.77, respectively. In conclusion, Lulu cattle has the potentiality to increase its productive and reproductive performance through improved health and husbandry practices.

Antioxidant activity of essential oil of Artemisia vulgaris collected from sub-tropical region of Bagmati province, Nepal.

S. Sapkota — 2022-12-16

Artemisia vulgaris is one of the highly used plant species as traditional medicine because of its antioxidant activity, anti-allergic effect and other several health benefits. This study was carried out with the objectives to explore the phytochemical constituents and assess the antioxidant property of essential oils of A. vulgaris found in sub- tropical regions of Bagmati province. Hydro distillation method was used for the extraction of essential oil and gas chromatography–mass spectrometry (GC-MS) analysis was performed to identify various phytochemicals present in essential oil. Evaluation of antioxidant activity by in vitro method was carried out by observing hydrogen peroxide scavenging effects of essential oils at different concentrations. GC-MS analysis showed 41 different phytochemicals including mono- and sesquiterpenes. Among them, highly expressed phytochemicals were Cadinene<gamma-> (14.95%), Caryophyllene(E) (9.32%), Camphor (8.74%), Thujone<alpha-> (6.57%), Eucalyptol (6.25%). Essential oil also showed scavenging effect against hydrogen peroxide with EC₅₀ value of 48.49. This preliminary study shows that essential oil of A. vulgaris can be used as a source of natural antioxidants, but in vivo and other clinical trials must be done for oral use.

Relationship between udder and teat conformations and morphometrics with milk yield in Murrah buffaloes

S. P. Poudel — 2022-12-16

Udder and teat conformations and measurements play a vital role in milk productivity and mastitis resistance in dairy buffaloes. The study was conducted on apparently healthy 24 Murrah buffaloes running on different parities selected from 3 different farms in the Chitwan district of Nepal to find the relation between phenotypic characteristics of udder and milk yield. The shapes of the teat and udder were evaluated by a visual appraisal that revealed 42.7% funnel, 26% bottle, 16.7% cylindrical, 14.6% conical-shaped teats, and 37.5% round, 33.3% bowl, and 16.7% goaty, and 12.5% stepped shaped udders. The average length, width, and depth of the udder were determined as 54.50±0.92 cm, 19.33±0.46 cm, and 27.50±1.10 cm, respectively, while the respective length and diameter of the teat were 8.46±0.17 cm and 3.59±0.07 cm. Within udder quarters, teat length was significantly different (p < 0.05) though the diameter was non-significant. However, the teat length and teat diameter differed along the teat and udder shapes showing the highest measures at bottle-shaped teats and goaty-shaped udder. The average milk yield/day recorded was 5.90±0.36 kg per buffalo. Higher milk yield was observed in the round-shaped udder and conical-shaped teat. The correlation of udder width (r= 0.237, p<0.05) and teat length (r= 0.222, p<0.05) was observed significantly positive but that of teat to floor distance (r= -0.232, p<0.05) was negative with milk yield. Hence, the selection of Murrah buffaloes for milk production traits should consider the dimensions of the teat and udder.

Effects of coated and briquette urea on yield and nitrogen use efficiency of rice at Rampur, Chitwan, Nepal

S. Marahatta — 2022-12-16

Nitrogen is one of the most limiting element for the growth and yield of rice. However, the imbalance use of conventional urea leads to loss of nitrogen from rice field, decrease nitrogen use efficiency, increase environmental pollution and cost of cultivation. This study was done to evaluate the response of polymer coated urea (PCU) and urea briquette (UB) on the yield and nitrogen use efficiencies (NUE) of rice on a sandy loam soil. The experiment was conducted at the agronomy research farm of Agriculture and Forestry University during the rainy season of 2018 in a randomized complete block design with three replications for each treatment (T₁ - control, 0 kg N ha^-1; T₂- Prilled urea, 150 kg N ha^-1 single application at basal; T₃- Prilled urea, 150 kg N ha^-1 standard split application; T₄-PCU, 150 kg N ha^-1 single application at basal; T₅-UB, 150 kg N ha^-1 single application at basal). The data on yield, and NUE were recorded and analyzed by using R studio. The physical and economic maximum dose of Nitrogen for these different types of urea were also calculated. Compared with single application of Prilled urea (3698 kg ha^-1), rice fertilized with Prilled urea with standard split application (4747 kg ha^-1), single application of PCU (5183 kg ha^-1) and BU (4787 kg ha^-1) had significantly higher grain yield and NUE. Economic maximum dose of nitrogen was reduced greatly for the single application of PCU (124 kg N ha^-1) compared to Prilled urea with standard split application (167 kg N ha^-1). Single application of PCU and UB can be considered as an alternative nitrogen fertilizer for rice even in the sandy loam soil.

Determining factors and impact of household income on dairy cattle insurance in Nepal

S. Subedi — 2022-12-16

Nepalese agriculture insurance market is dominated by livestock sector and cattle are the most popular class of animal in livestock production system. This study was conducted to identify the determining factors and impact of household income on dairy cattle insurance. This study was based on the field survey conducted in Chitwan and Nawalparasi districts of Nepal. A total of 160 households were sampled using a stratified simple random sampling technique. Data were collected using a pre-tested interview schedule and focus group discussion (FGD) in 2017. The result of t-test showed annual household income, income from milk sell, and average cattle holding significantly higher in cattle insurer farmers than that of non-insurers. A probit model was used to assess the factors affecting the decision for the adoption of cattle insurance. The probit model revealed that cattle breed, access to loan, income from livestock, and number of cattle had a positive and significant relationship with the adoption of cattle insurance whereas, household size and district dummy had a negative and significant relationship with the adoption of cattle insurance. Income regression function revealed that the adoption of insurance, the number of cattle, and the district of the respondents had a positive and significant relation with income from livestock. The instrumental variable model adopted to combat endogeneity bias showed that adoption of insurance and district of the respondents had a positive and significant relation with income from livestock. Although the results are farmers specific, findings have implications for policymakers regarding promotion of improved breeds and facilitation of farm credit.

Factors affecting adoption of major adaptation strategies against drought among summer vegetables growers in central Nepal

A. P. Subedi — 2022-12-16

Climate change is one of the critical challenges in the field of agriculture and drought is one among the important effects of global climate change affecting summer vegetables in central Nepal. A research was conducted in central Nepal to seek out factors affecting adaptation strategies against drought among summer vegetables growers. A semi-structured questionnaire was used to collect primary data from 300 households adjoining Trishuli Narayani River corridor equally divided among three districts namely Chitwan, Dhading and Nuwakot. Data obtained were analyzed using descriptive statistic and logit model. Irrigation canal, choosing appropriate crop varieties, mulching, adjusting planting time and using organic manure were identified important adaptation strategies for drought within the study areas. Distance of vegetable farm from river, knowledge of climate change with the respondents, training provided to farmers on vegetable farming, access to cooperative was seen significantly affecting farmers to settle on those adaptation strategies against drought. Adopting different practices against drought found to be correlated with topography or agro climatic regions as well. Nuwakot and Dhading with high altitude got less chance of using organic manure and mulching practice in comparison with Chitwan but its opposite with other adaptation practices like adjusting planting times, changing crop varieties and using irrigation canal. Policy makers and extension workers should focus more on knowledge input based on topography or agroclimatic regions as well about climate change adaptation practices among the farmers, hence providing more trainings on vegetable farming, increasing the access to cooperatives and other organizations could ultimately help to strengthen vegetable growers to adopt those adaptation practices.

Understanding the role of key determinants towards realizing food insecurity amongst the rural households: A case from Bajhang and Morang districts of Nepal

N. Bastakoti — 2022-12-16

Food insecurity is one of the single largest determinants to challenge Nepal from realizing its ambition of graduating to a developing country. In line with the imminent national challenge, this study has tried to delve into the real-time findings from the rural part of the country to understand the crucial determinants of food insecurity. A household (HH) level survey with a sample size of 502 was adjudged using Krejcie and Morgan (1970) method. Semi-structured HH survey was administered to collect the socio-economic status of the respondent. Household Food Insecurity Access scale (HFIAS) was used to assess HHs food insecurity, whereas poverty status was assessed using the multidimensional poverty index (MPI). Finally, to identify the determinants of food security binary logistic regression technique was used. The MPI adjudges the aggregate status as 21%, 30.6% in Bajhang, and 14% for Morang. HFIAS tool unveiled that 47% HH were food secure. The disaggregated figure stands as 46% and 48% of households being food secure in Bajhang and Morang districts, respectively. Among the surveyed households, half of the households expressed food insecurity as the greatest concern and the consequential uncertainty ahead. The assessment further found that the Per Capita Income score (p<.01), access to financial institutions (cooperative) (p<0.01), holding livestock (p<.05), and expenditure on food (p<0.01) have a positive relationship in the case of Bajhang household. On the other hand, wage labor (p<0.01) earning members in the village (only for Morang), MPI poor (p<0.05) HHs and abroad migration (p<0.05) (only for Bajhang), ethnic cast Dalit (for both) (p<.05) had a significant negative relationship on household food security.

Restoring competitive and commercial agriculture in river basin of Nepal, focus in Daraudi river, Gorkha

S. Pokhrel — 2022-12-16

Daraudi river basin and sub-basins consisted of numerous fertile tars, phants and upland (24173 ha) supplying foods in settlements and neighboring cities. Agriculture in this area is no more attractive because of small size land/farm holdings (0.25ha/HH), subsistence farming, high production cost, higher agricultural risks, low productivity and low income. The aim of this research was to investigate the way of economic resilience by means of commercial agriculture, agricultural risk reduction, implementation of agriculture engineering and linking farm activities to services. Relevant literatures were reviewed, field verification and interactions were made in different rural municipalities/municipalities in the year 2021. The study found that the maize and millet in upland and rice-based cropping system in irrigated land are common in water shed and basin area. Cattle (35,709), buffalo (27,921), goat (82,358), sheep (6,806), pigs (5,430) and chicken (1,92,584) are major livestock kept. The area is in balance only on cereals (17,864 mt) and spices (735.3 mt/year) and deficit in all other foods. Land fallow (27.0%) is increasing because of youth out migration (0.72 persons/HH/year). The respondents demanded establishment of larger farm sizes (82.2%) from land pulling, farmers/entrepreneurs organizations development (54.4%), identification of profitable and competitive value chain for commercial production (74.4%), promote agriculture engineering activities (94.4%), minimization of agricultural and environmental risks (57.8%) and creation of local off farm employment (56.7%). They also suggested to have a commercial farm operation guideline (46.7%), linking all farm operation to services (55.6%, linking neighboring small producers with commercial farm for services (52.2%) and establishing a strong collaboration among all stakeholders in an integrated approach (42.2% respondents). It is recommended to address the demand of the respondents for restoring the competitive and commercial agriculture in river basin of Daraudi river. Similar recommendation may apply to other river basins in Nepal.

A study on activation of polyethylene glycol and its characterization by infrared spectroscopy and thin layer chromatography

R. Bashyal — 2022-12-16

Polyethylene Glycol (PEG) is the most popular polymeric material used for alteration and control of biodistribution. PEG may increase the lifetime of “drug carrier” assembly which helps in administering lower concentration of the “drug carrier” composite. It has been used widely for the modification of carriers used in therapeutics because PEG offers a shielding characters that avoids rapid renal clearance from the body. This study was carried out at Dolphin Institute of Biomedical and Natural Sciences, Dehradun and Indian Institute of Technology (IIT), Roorkee, India during May-July 2005. Activation of PEG of different molecular weight (400 Da, 4000 Da, 8000 Da and 20,000 Da) was done using dry benzene, Triethylamine, Ethylene dichloride and 4-nitrophenyl chloroformate. Reaction mixture was monitored on TLC using EDC: Methanol (7:3). Then reaction mixture was portioned between EDC & water. The lower fraction in separating funnel of EDC was collected & concentrated on rota evaporator to get activated PEG. From the above reaction and structure it was clear that 4-Nitrophenyl Chloroformate contains two highly electronegative groups i.e. NO₂ and Cl. These two groups interact with each other resulting in neutralization of polarity. It then acts as non-polar molecule and shows high affinity for mobile phase (methanol & EDC). Therefore, 4-Nitrophenylchloroformate has the highest mobility and PEG has lowest mobility. From IR Spectroscopy it was found that the peak of Hydroxyl group- (OH) of PEG was at 3400- 3450cm^-1. The peak of C-Cl bond was found at 746 cm^-1. But after the reaction between PEG and 4-Nitrophenyl Chloroformate the- OH peak was found not so deep as in PEG. The peak was somewhat short and broad.

Clinical evaluation of Ageratum houstonianum Mill intoxicated goats

R. Bhatta — 2022-12-16

Ageratum houstonianum Mill (A. houstonianum) is a widespread, highly invasive, and drought-resistant annual semi-shrub easily found in the pasture fields. It is called Gandhey Jhar locally. This study was conducted at the livestock farm of Rampur Campus, Rampur, Chitwan, Nepal, to determine the clinical progression and clinical parameters in A. houstonianum intoxicated goats to diagnose its toxicosis in small ruminants. Full blossomed A. houstonianum was fed ad libitum to six goats until the death of the animals. The time to develop the clinical signs and symptoms in goats ranged from 22 to 49 days. All the goats exhibited similar symptoms and signs such as stiffness of the neck, low temperature, respiratory distress, low pulse, anorexia, ruminal atony, general weakness, and finally, recumbency till death. After the onset of clinical symptoms, the entire clinical course persisted for 10-15 hours, followed by death. Two goats died on the 22nd day, and the rest goats died on 27th, 46th, 48th, and 49th days respectively. Hematologic examination revealed a significant decrease in hemoglobin and an increase in total WBC count. The serum biochemical values showed substantial alterations in ALT, AST, ALP, GGT, albumin, direct bilirubin, total bilirubin, glucose, urea nitrogen, and creatinine concentrations. These biochemical changes suggested hepatic and renal dysfunction. Therefore, clinical signs, hematology, and serum biochemistry can be of optimal diagnostic value for the A. houstonianum intoxication in goats.

Isolation and antibiotic sensitivity of Salmonella typhimurium isolates from poultry farms and slaughterhouses of Chitwan, Nepal

S. Singh — 2022-12-16

Nepalese poultry sector is progressing rapidly contributing around 4% of GDP with flourishing impact to provide sustainable and cheapest protein as source of human food. However, with the accelerating pathway, this industry is shed-back by outbreak of several infectious and zoonotic diseases impacting huge economic losses. Salmonella also cause infection in poultry birds and constitutes the largest reservoir of Salmonella organisms in nature. S. typhimurium is an unadopted serotype of Salmonella that may be transmitted to human, animals (poultry) and environment from contaminated food, feed and water. Use of antibiotics, good farm management practices and biosecurity are the treatment and control measures of this disease in poultry production. Development of antibiotic resistant strains of S. typhimurium thus not only pose considerable threat to clinicians, but is also of public health concern as these resistant strains after ingestion are capable of transferring resistance to other pathogens. The present study was undertaken to determine prevalence and antibiotics sensitivity of S. typhimurium strains isolated from domestic poultry from Chitwan, Nepal. Out of 79 farm and 23 chicken slaughterhouse sampling sites, the 107 (19.45%) out of 550 cultured specimens were confirmed for S. typhimurium. Amongst various antibiotics used for in vitro sensitivity testing, the two antibiotics: Colistin (Cl) and Enrofloxacin (Ex), were found to be 100% effective, whereas out of 22 antibiotics, 18 antibiotics showed weak to strong resistance pattern against S. typhimurium isolate. In the present study, Polymyxin and fluoroquinolone antibiotics were found to be most effective against S. typhimurium. Understanding the source of exposure to pathogens (especially resistant pathogens) provides some insight into antibiotic use and misuse in the region. Looking through the lens of One Health approach, the regulation of antibiotic use in animal medicine has direct implications for human health through the increased resistance of foodborne pathogens to vital antibiotic therapy. Thus, judicious use of antibiotics based on their sensitivity pattern should be practiced.

Synthesis of nanoparticles of Poly (ethyleneimine) and their characterization by transmission electron microscopy, thin layer chromatography, and infrared spectroscopy

R. Bashyal — 2022-12-16

Intracellular gene delivery alters the expression of a gene and corrects a defective gene that may be the cause of a disease or a disorder. Nonviral gene delivery is more appropriate than viral-mediated due to their low cytotoxicity and immunogenicity. Amongst these, polycationic nanoparticles i.e. Polyethyleneimine (PEI) were used most successfully. The PEGylation of such cationic polymer reduces its cytotoxicity. Different molecular weight poly (ethylene glycol) was used for the PEGylation of such cationic nanoparticles which have an individual effect. For this purpose, the PEG is esterified, which was then reacted with a cationic polymer. Four different molecular weights of PEG were used. The size of nanoparticles so formed depends upon the molecular weight of PEG. So formed nanoparticles were dialyzed, lyophilized, and then characterized by IR and TEM. The nanoparticles so formed are directly affected by the different molecular weights of PEG. Higher the molecular weights of PEG smaller size of nanoparticles so formed but only up to a limited extent. The decreasing order of nanoparticles as an increment of molecular weight of PEG was found as a -0.85 coefficient of correlation. The smaller-sized nanoparticles have higher transfection efficiency than larger-sized nanoparticles. So, the higher the molecular weight of PEG higher will be the transfection efficiency.

Effect of Trichoderma isolates on Sclerotium rolfsii Sacc.

P. Adhikari — 2022-12-16

Sclerotium rolfsii Sacc. is one of the most important plant pathogens commonly causing root rot, stem rot, wilt and foot rot in various crop species. A wide range of host, profuse mycelial growth, and ability to produce persistent sclerotia makes them difficult to control. Biological control using Trichoderma could provide a sustainable tool for the management of diseases caused by S. rolfsii. One hundred four Trichoderma isolates were evaluated against S. rolfsii in vitro by dual culture. Of them, 30 Trichoderma isolates found effective were selected to study parasitization of sclerotia of S. rolfsii in vitro. Similarly, four Trichoderma isolates found effective in vitro were used to study their ability to parasitize sclerotia of the pathogen in soil. Trichoderma isolates varied significantly (p<0.001) for both the inhibition percentage and biocontrol index. However, they showed a differential effect as Trichoderma isolate T₇₃, Forest soil had highest inhibition (96.96%), while Trichoderma isolate T₄₉, Bhaktapur showed the highest bio-control index (99) against S. rolfsii. Trichoderma isolates T₄₉, Bhaktapur and T₈₇, Forest soil showed promising results in controlling S. rolfsii in vitro. Both isolates were also able to parasitize and reduce the germination of sclerotia in the soil. The present study demonstrated that selected Trichoderma had potential in controlling Sclerotium rolfsii.