Most of the farmers in mid-hill areas introduce plastic houses, naturally ventilated poly-houses or other types of protected structures for year-round vegetable production. Capsicum is a commonly cultivated crop inside these structures. Optimizing nitrogen (N) fertilization during capsicum production is critical for increasing crop yields, increasing nitrogen use efficiency (NUE), increasing net profit of farmers and minimizing the loss of nutrients into the environment. A study was carried out to identify the optimal nitrogen dose for enhancing Capsicum yield, nitrogen use efficiency (NUE), and net profits within a naturally ventilated polyhouse at the Directorate of Agriculture Research, Lumle, Kaski, Nepal, in two consecutive years; 2019 and 2020. Eight nitrogen levels (0, 100, 125, 150, 175, 200, 225, and 250 kg/ha) were evaluated using a randomized complete block design with three replications. Data were collected on each treatment’s effect on yield, yield-related characteristics, nitrogen use efficiency (NUE), and production cost. Nitrogen application at 225 kg/ha resulted the highest fruit yield and net benefit; however, N levels between 200 and 250 kg/ha showed similar effect on yield, yield-related components and net benefit. Considering agronomic, economic, and NUE factors, an N dose of 200 kg/ha along with 30 t/ha farmyard manure (FYM) was found to be optimal for Capsicum cultivation in a naturally ventilated polyhouse at Lumle, Kaski, and this N dose can be recommended for similar soil and agroecological conditions in Nepal.

An experiment was conducted during 2020 and 2021 in farmer’s fields at Machhapuchhre-06, Kaski, Nepal to determine the optimal amount of nitrogen for increasing potato yield, nutrient use efficiency (NUE) and net profits. Seven different levels of nitrogen (0, 25, 50, 75, 100, 125, and 150 kg/ha) were evaluated in a randomized complete block design with three replications. The effects of different levels of nitrogen on yield, yield-attributing traits, NUE, and production cost in potato cv. Janakdev were observed and recorded. It was found that applying nitrogen at the rate of 75 kg/ha, combined with 20 t farm yard manure (FYM)/ha produced the highest tuber yield and benefit-cost ratio. Application of nitrogen more than 75 kg/ha did not result any significant increase in yield and yield components. Considering agronomic, economic, and NUE factors, nitrogen application at 75 kg/ha along with 20 t/ha FYM was found to be optimal for the potato cultivation in Machhapuchhre, Kaski. This finding is also recommended for similar soil and agro-ecological conditions of Nepal.

Mandarin (Citrus reticulate Blanco) has been cultivated in 56 districts of Nepal. Huge losses in mandarin were reported and use of safer alternatives to synthetic chemicals to solve post-harvest losses is a matter of great concern. An experiment was conducted at the Directorate of Agricultural Research, Lumle for two consecutive years 2019 and 2020. Mandarin having similar maturity indices were harvested and transported to DoAR, Lumle. The fruits were treated with five different botanicals (garlic extract @ 10 %, ginger extract @ 10 %, aloe vera extract @ 10 %, neem extract @ 10 %, and control) allocated in randomized complete block design with four replications. The post-harvest study was conducted for 3 weeks under laboratory conditions (7.9 ± 3° C and RH 74 ± 4%). Different parameters such as physiological loss in weight (PLW), decay loss, total soluble solid (TSS), titrable acidity (TA) and fruit weight to juice ratio were recorded. Fruit treated with ginger extract @ 10 % recorded the minimum physiological loss in weight (6.31% and 5.15%), minimum decay loss (16 % and 17%) in the year 2019 and 2020, respectively. Highest TSS: TA ratio (13.54 and 12.79) and fruit weight to juice ratio (0.33 and 0.35) was also observed in fruit treated with ginger extract @ 10 % in both years. In both years, results obtained in the fruits treated with ginger extract was followed by fruit treated with aloe vera extract and garlic extract. Control treatment gave the poor result as compared to ginger extract @ 10 %. Thus, this study concluded that the use of ginger is suitable for postharvest treatment of mandarin fruit to increase its shelf life and maintain its quality parameters.

Acid Lime (Citrus aurantifolia var. SunKagati-1) has been cultivated in 67 districts of Nepal. Its cultivation is becoming increasingly popular among farmers in Nepal. However, adequate post-harvest loss reduction measures are lacking. A field experiment was conducted in lime orchards in Chitwan during August-September 2019 and 2020. Pre-harvest spraying of different concentrations of calcium (0.1, 0.2, and 0.3%) and boron (0.2, 0.4, and 0.6%) in lime fruit trees was done before 45 and 30 days of fruit harvest. Fruits with the same maturity indices were harvested separately from the treated plants. The post-harvest study was conducted for 1 month under laboratory conditions. Different parameters like physiological loss of weight (PLW), decay loss, total soluble solids (TSS), titrable acidity (TA), ascorbic acid content (vitamin C), and freshness were recorded. Minimum PLW (18.2%) and decay loss (14.3%) were observed in boron (@0.6%) treated fruits. At the end of the experiment, minimum TA (1.79 and 2.12%) was recorded from boron (@0.6%) treated fruits in both years. Calcium (@0.3 %) and boron (@0.4 %) treated fruits expressed the maximum values for TSS in 2019 (9.67ºbrix) and 2020 (7.73 ºbrix), respectively. Fruit harvested from fruit trees sprayed with boron (@0.6%) showed the highest ascorbic acid content (55.47 and 49.61 mg/100g) and better lime freshness (2.67 and 3.0) in 2019 and 2020, respectively. This study concluded that the use of boron @0.6% as a pre-harvest spray can prolong the storage life of sour lime and maintain the fruit quality under environmental conditions of a mid-hill situation.

Mandarin (Citrus reticulate Blanco) falls under Rutaceae family is the major fruit crop of mid-hills region of Nepal. Syangja being the Citrus super-zone, the Mandarin area and production in this district has been significantly expanded and increased. The Mandarin fruit industry grapples with major challenge of huge post-harvest losses. Two different postharvest studies were carried out in the same time at Syangja cold-store. Different concentration of calcium chloride (0, 2% and 4%) was used to enhance the shelf life of mandarin along with the study on physiology of mandarins (harvested and stored in different date) after removal from cold storage was done. Decay loss caused by Green and Blue mold (Penicillium spp) was reduced when mandarins were dipped in a 4% solution of calcium chloride and kept in cold storage. Mandarins harvested and kept in cold storage on 1st week of December had comparatively low weight loss and decay loss. In general, the mandarins produced in Syangja district must picked safely from second fortnight of November to first week of December and stored them in cold storage by treating with 4% calcium chloride.

Agro-morphological characterization and genetic diversity analysis is pivotal to identify elite genes for further improvement of germplasms. In Spring 2022, 52 spring (Chaite) rice accessions were evaluated for 12 agro-morphological traits in alpha lattice design with two replications under irrigated condition at agronomic farm of Gauradaha Agriculture Campus, Jhapa, Nepal. Results showed the existence of considerable amount of diversity in rice accessions. The first three principal components (PC1, PC2 and PC3) with eigen value greater than one were identified with a total cumulative variation of 95.04% showing that the accessions could be grouped at least into three main varied classes. The accessions were grouped into 5 clusters. The accessions falling in cluster II had the maximum grain yield. The accessions namely Hardinath-1 (4.87 t/ha), IR17A3019 (4.37 t/ha), IR17A2949 (4.12 t/ha) were found to have high yielding accessions. High genetic variability among the rice accessions was found for the traits viz., grain yield, thousand grain weight, length breadth ratio, days to flowering, days to maturity, panicle length, effective tiller per hill and have pertinency in future spring rice breeding programs for the selecting potential parent lines based on those traits.

Walnut (Juglans regia L.) of seedling origin creates large variability within this crop. A research study was carried out at Directorate of Agricultural Research, Lumle, Kaski and Marpha, Mustang to characterize and deciphers the variability of thin-shelled walnut for further selection, conservation and variety registration. Walnut orchard of Mustang district was surveyed in March, 2018 and 50 walnut trees were labeled according to its flowering and flushing time. 36 accessions of thin-shelled walnut were characterized on 17 different parameters regarding growth habit, bearing habit, fruit and kernel characteristics. Around 88.89% trees exhibited terminal fruiting habit and remaining showed lateral fruiting habit. Three type of tree shape was noticed as spreading round, semi-erect and erect. Huge variation in nut shape was observed having 50% trees were with circular nuts. Four types of shell strength was recorded; 11.11% accessions having papery shell, 27.78% having weak shell, 47.22% having intermediate shell and 13.88 having strong shell strength. Average nut yield of trees ranged from 15-75 kg with an average of 26.67 kg. Nut weighted from 5.96-18.99 g with an average of 11.14 g. Kernel weight ranged from 2.8-8.92 g. More than 50% shelling was recorded in 13 accessions. The kernel quality of 14 accessions (out of 36) showed 5 rank (Excellent quality); and remaining 22 accessions showed 4 rank (Good quality). Based on this characterization, 13 accessions were selected and recommended for further multiplication and variety registration.

Litchi (Litchi chinensis Sonn var. Muzaffarpur) is cultivated in 57 districts of Nepal. However, proper post-harvest loss reduction activities are lacking, resulting in significant losses every year. In June 2023, an experiment on Litchi post-harvest was conducted at HRS, Malepatan. The Litchi fruits were uniformly mature and treated with varying concentrations of potassium metabisulfite (50, 75, 100, and 125 ppm) and Bavistin at 100 ppm. They were then stored at ambient conditions (29±4°C and RH 75±5%) for 10 days. The following parameters were recorded: physiological loss in weight (PLW), decay loss, total soluble solids (TSS), titratable acidity (TA), ascorbic acid content (Vit-C), and fruit weight to juice ratio. The fruit that was treated with 50 ppm of potassium metabisulphite recorded the lowest PLW at 20.12%. The fruit treated with 125 ppm of potassium metabisulphite had a minimum decay loss of 23.08%. The control treatment had the highest TSS at 23.65% with a minimum TA of 0.50%. The fruit treated with 100 and 125 ppm of potassium metabisulphite had the maximum ascorbic acid content at 87 mg and 85 mg, respectively, and the highest fruit weight-to-juice ratio at -2.80 and 2.73, respectively. Therefore, this study concludes that applying potassium metabisulfite at a concentration of 100-125 ppm is suitable for postharvest treatment of Litchi fruit to prolong its shelf life and maintain its quality parameters.

Rice is the most important staple food crop and plays a vital role in ensuring national food security in Nepal. Rice yield is largely determined by nitrogen management strategy and improving the effectiveness of nitrogenous fertilizer for grain production has long been a challenge. A field experiment was conducted in the sandy loam soil of Lumle, Kaski, Nepal in 2019 and 2020 to assess the effect of neem oil-coated urea (NCU) and common urea (CU) with varying levels of nitrogen (N) on rice yield and nitrogen use efficiency (NUE). The experiment with 7 treatments comprising the combinations of two types of nitrogen source (CU and NCU), three N levels (50, 100, and 150 kg/ha) and one control treatment without N, were allocated in a randomized complete block design with three replications. Increased nitrogen rates up to 100 kg/ha supplied through NCU significantly improved grain yield, yield components, and nitrogen use efficiency of rice. Application of NCU reduced nitrogen fertilizer use by up to 33 % while producing maximum yield and significantly increased agronomic nitrogen use efficiency (ANUE) and nitrogen partial factor productivity (NPFP) compared with CU. This suggests that the use of NCU with an optimum rate can be a viable option for appropriate N management in rice production.

In Nepal, rice is the major staple food crop and is ranked first as a cultivated crop. Nitrogen is one of the most important factors limiting its yield. There has been an overuse of nitrogen fertilizer in rice fields resulting in low N use efficiency and high loss of nitrogen. A field experiment was carried out on acidic sandy loam soil of the Directorate of Agricultural Research, Gandaki, Lumle, from June to November 2016 and 2017 to evaluate the performance of cold-tolerant rice (Lumle-2) and nutrient use efficiency as affected by various levels of nitrogen application. The experiment was laid out in a randomized complete block design with five different level of nitrogen as treatments (0, 50, 100, 130, 150 Kg N ha-1) and replicated four times. Phosphorus, potassium and FYM were applied at the recommended dose. A significantly marked increment in grain yield was noticed in both years as the nitrogen level increases up to 130 Kg N ha-1. However, when the nitrogen dose exceeded 130 Kg N ha-1 have decreasing effect in grain yield, straw yield and NUE. The productivity (4.35 t ha-1) and NUE of cold tolerant rice (Lumle-2) can be improved significantly by applying an optimum level of N fertilizer up to 130 Kg N ha-1.

An experiment for two consecutive years (2017 and 2018) was conducted to evaluate the use of mulching materials in increasing productivity and profitability of potato production. The experiment was conducted in Randomized Complete Block Design (RCBD) with five different mulching materials including control replicated for four times namely, banmara (Agertina adenophora) weed (T1), black polythene sheet (T2), white polythene sheet (T3), commercially used mulch paper having black color outside and silver color inside (T4) and farmers practice (T5) as a control with no mulch. The research result revealed that all the mulching materials significantly (p value ≤ 0.05) increased tuber yield and yield attributing characters of potato as compared with control (no mulch). The highest tuber yield was obtained from mulching with commercial mulch paper followed by mulching with black polythene sheet in both years. Mulching with banmara also produced significantly (p value ≤ 0.01) higher tuber yield than no mulch plot in the year 2017 and 2018. Mulching practices significantly (p value ≤ 0.05) improved the soil available phosphorus. The incremental benefit cost ratio was highest (2.97) in the mulched with banmara followed by commercial mulch paper (2.12). The banmara mulch was also profitable with comparatively higher tuber yield.

A detailed soil inventory study using Global Positioning System (GPS) and Geographical Information System (GIS) was conducted in Nalgad Municipality of Jajarkot, Nepal in 2019. A preliminary reconnaissance survey during pre–field activities and detail field work was carried out to study the soil type and physico-chemical properties based on the soil pit. A total of 51 soil pits were taken in the field representing varied micro topography. Soil Sample pits covering all the units were dug based on the interpreted soil map, topographical map, ZY-3 Satellite imagery for determination of soil profile. Soil classification of the area was done based on the USDA soil taxonomy and the dominant soil orders found in the region were Entisols (15.13 %) and Inceptisols (83.60%). A total of 51 geo-referenced composite soil samples from a depth of 0-20 cm was collected from each pit and analyzed in laboratory for texture, soil pH, soil organic matter, total nitrogen, available phosphorus and exchangeable potassium. Majority of the soil are loam and loamy sand type. There is very low to high level of organic matter present in the study area with more proportion of land under high range of organic matter (64.98%). Total Nitrogen content in soil of the study area ranges from very low to very high level with high level of Nitrogen (65.51%) in major proportion. Low to very high level of available phosphorous content was found in the study area with the dominance of very high level of phosphorous (71.40%). Exchangeable Potassium level in the study area is very high to low. Around 42% land have very high level of potassium. From the soil test result, major nutrients status in soil were found to be good but integrated land management practices should be encouraged for improving land productivity. The generated soil maps may be helpful to stakeholders for planning, monitoring and evaluating the soil status for effective agricultural production.

This study was conducted to identify the factors affecting the adoption of banana insurance in Chitwan district of Nepal. A total of 160 samples (80 insurers and 80 non-insurers of banana producers) were selected randomly to collect primary data. Primary data were collected by conducting household survey using personal interview method in the month of September 2019. The logit model was used to identify the factors affecting the adoption of banana insurance policy among farmers. The result showed that the explanatory variables, area under banana cultivation, membership to cooperatives, and awareness about the agriculture insurance, perception of farmer about the necessity of crop insurance, agriculture extension services, and age of banana orchard were significantly contributing to the adoption of banana insurance policy. It also revealed that organization of awareness program, mobilization of groups and cooperatives were the important tools to promote banana insurance program. The findings would be helpful to make the insurance program more effective and hence increase the adoption of insurance policy and ultimately benefit farmers by enhancing their ability to manage risks in agriculture.

Kiwifruit is usually propagated by grafting and cutting. Suitable method of grafting in Kiwifruit should be identified to elaborate the commercial production. To evaluate the success rate of scion varieties with different grafting methods in Kiwifruit a study was conducted for two consecutive years 2018 and 2019 at Lumle, Kaski. Five different varieties of Kiwifruit as scion (Allison, Bruno, Hayward Oblong, Hayward Oval and Monty) and three different grafting methods (tongue, veneer and wedge) were used to identify successful method of grafting in Kiwifruit. Grafting was done on January 1st and 2nd in both years. In the first year, shoot length was recorded highest in Hayward Oblong with veneer grafting (96.10cm) whereas shoot diameter was obtained highest in Monty with wedge grafting (6.61mm). Similarly in the second year shoot length was recorded highest in Hayward Oblong with veneer grafting (97.10 cm) and shoot diameter was observed highest in Monty with wedge grafting (6.71mm). In both years, the highest (100%) graft success was recorded in Allison with wedge grafting.

In Nepal, scientific forest managementhas been practiced as an effective forest management technique to utilize forest resources sustainably. However, the program has faced many controversies such as intentional logging of only high-valued timber species like Shorearobusta. In addition, few believe this program is severely affecting the regeneration productivity and species diversity in the natural forests. In order to address these issues, we examinedthe regeneration condition and plant species diversity in the stands where scientific forest management operations were carried out. The data related to regeneration status and species diversity were collected using a systematic random sampling of the selected stands. Our results showed good regeneration conditions (Seedling >5000, Sapling>2000) in all the studied stands. The tree species community was dominated by S.robusta(Sal) followed by Schleicheraoleosa (Kusum) and Casia fistula (Rajbriksha). The value of diversity indices of different species varied significantly between felling series. The highest diversity was found in the second year felling series with the Simpsons Index of dominance value 0.6934 and the lowest species diversity was in the first year felling series with a value of 0.8448. It can be recommended that the regeneration felling practice has helped in promoting the regeneration condition and growth.

Field experiments were conducted during the winter season of 2016/17 and 2017/18 to assess the effect of biochar application in combination with different nutrient sources on cauliflower (Brassica oleraceae var. botrytis) production in sandy loam soil. The experiment was conducted using a Randomized Complete Block Design (RCBD) with ten different treatment viz., Farmer’s practice as control treatment, Recommended dose of fertilizer (200:120:80 kg NPK/ha), Composted biochar @ 1t/ha, Urine Soaked biochar @ 1t/ha, Mineral fertilizer (200:120:80 kg NPK/ha) mixed biochar @ 1t/ha, Humic acid soaked biochar @ 1 t/ha, Composted biochar @ 2t/ha, Urine Soaked biochar @ 2t/ha, Mineral fertilizer (200:120:80 kg NPK/ha) mixed biochar @ 2t/ha and Humic acid soaked biochar @ 2 t/ha, each replicated for three times. The application of biochar in combination with mineral fertilizers significantly increased the yields of cauliflower in both consecutive years. Application of biochar @ 2 t/ha along with mineral fertilizer at recommended dose increased curd yield of cauliflower by 37 % compared to that of only mineral fertilizer application and by 59 % compared to that of control treatment. Biochar and inorganic sources of nutrition together in soil showed superiority over other practices and would be of immense value to increase the productivity of cauliflower.

Artificial crossing between species and varieties has been effective in producing new gladiolus cultivar with desirable traits. The seeds obtained from the total of twelve inter-varietal cross lines were raised in nurseries in 2013. The corms and cormels were selected yearly from the first phase to the fourth phase of selection. Forty seven inter-varietal cross lines and one check genotype were assessed in preliminary non-replicated trial in 2017 in the field of Regional Agricultural Research Station, Lumle, Nepal. A total of twenty five inter-varietal cross lines of gladiolus was selected, and assessed to develop new productive and attractive varieties of gladiolus on the basis of sixteen traits: the first spike emergence, complete spike emergence, the first floret loosening, maximum number of floret opening at a time, floret diameter, number of florets /spike, days to the seventh floret wilting, flower life, plant height, spike length, rachis length, number of spikes/ mother corm, number of marketable spikes /mother corm, number of filled capsules/spike, number of unfilled capsules/spike and total number of capsules/spike. Forty six inter-varietal cross lines were selectively reduced to twenty five inter-varietal cross lines after they had been assessed in the preliminary trial. Eventually ten cross lines: HRSDG-013-2.17(A), HRSDG-013-7.4(B), HRSDG-013-7.8(A), HRSDG-013-7.8(B), HRSDG-013-8.5(A), HRSDG-013-8.16(A), HRSDG-013-9.12(A-2), HRSDG-013-10.24, HRSDG-013-11.7(B) and HRSDG-013-11.17(B-2) are likely to be promoted for replicated trial so as to develop new desirable varieties in future.

A field experiment was conducted to assess the effects of biochar application on soil properties and production of Radish (Raphanus sativus L.) on loamy sand soil. The experiment was conducted using a Randomized Complete Block Design (RCBD) with five levels of biochar (0, 5, 10, 15 and 20 Mg ha-1), each replicated for four times. The application of biochar significantly increased the biomass, root and shoot yields of radish. The soil organic matter, soil bulk density, total nitrogen, available phosphorus and available potassium contents of soil also significantly increased with the addition of biochar; however, the pH of the soil did not differ significantly, but increased with increasing rates of biochar application. The highest soil organic matter, total nitrogen, available phosphorus, and available potassium contents of soil and biomass, root and shoot yields of radish were obtained from 20 Mg ha-1 application of biochar and the lowest soil bulk density was obtained from the same level of biochar application. Biochar application to soil would be of immense value to improve soil and plant productivity.