Holotrichia longipennis Blanch. (Coleoptera: Scarabaeidae) is a serious pest of commercial crops in Siduwa, Dhankuta, Nepal. Seven indigenous isolates of entomopathogenic nematodes (Steinernema lamjungense LMT5, S. lamjungense SS4, S. everestense DKP4, S. abbasi CS1, S. sp. KL1, Heterorhabditis indica CK2 and H. indica CK6) were used in a series of bioassays against the insect. All isolates showed an increased dispersal in response to H. longipennis. Nematodes were more attracted towards third instar larvae than to second instars. Differences in penetration and multiplication in the insect were observed amongst the seven isolates. Steinernema lamjungense LMT5, S. everestense DKP4 and S. abbasi CS1 caused greater mortality than other isolates to different developmental stages. Pupae and second instar larvae were more susceptible than third instar larvae. Significant differences were observed in LT 50 values of the isolates against different stages of H. longipennis. Three isolates (S. lamjungense LMT5, S. everestense DKP4 and S. abbasi CS1) along with a commonly used insecticide (chlorpyrifos) were tested against this insect in pot and field experiments. In pot experiments using maize and cabbage as a host crop, S. lamjungense LMT5 and S. everestense DKP4 performed better than S. abbasi CS1 and yielded a mortality comparable with chlorpyrifos. Similar results were observed in field experiments 3 weeks after nematode application. These experiments overall suggest S. lamjungense LMT5 to be a promising biocontrol agent against H. longipennis followed by S. everestense DKP4 and S. abbasi CS1.

Agriculture is the mainstay between humans and the environment. The existence of arbuscular mycorrhizal fungi (AMF), on the earth, is about 600 million years ago. The application of mycorrhizae as biofertilizer is in increasing trend. Mycorrhizae improve several agricultural practices like better nutrient cycling, improving crop yield, and remediation of toxic heavy metals from soil. There is much variation in arbuscular mycorrhizal association although 80% of the plant species are infected with mycorrhizae. Mycorrhizal dependency (MD) is defined as the degree to which a host plant is dependent on AMF to produce maximum growth or yield at a given level of soil fertility. Plant with high MD need to feed with a higher amount of carbon and lipid to the fungus than a plant with less MD. Mycorrhizae modify, maintain, and create habitat by directly and indirectly regulating biotic and abiotic environments. Mycorrhizae derived photosynthetically formed C for the growth and uptake, tolerance against abiotic stress such as drought, heavy metals, salinity as well as protecting from pathogen attack to host plant and preventing from erosion. Application of ZnO would have been the probable solution of mitigating drought.ZnO treatment decreased the adverse effects of drought stress in plants by enhancing antioxidant enzyme activity and changing physiological parameters. Heat stress affects many processes in a variety of plants as water relations, nutrient uptake, photosynthesis, assimilate partitioning, respiration, growth, and reproduction, and induced oxidative damage. Foliar application of ZnSO4.7H2O effectively alleviated by enhancing Zn concentration, superoxide dismutase activity, chlorophyll content, Fv/Fm ratio, and photosystem II under heat stress. In maize, there is a substantial reduction of germination above 37oC. All the parameters recorded in wheat, namely, no of tillers, plant height, spike length, no of spikelets per spike, no of grains per spike, 1000 grain weight, biological yield, grain yield and harvesting index, Ca, Mg, Fe, Zn, Cu and protein content are significantly affected by the mycorrhizal application. Almost 25% of recommended dose of phosphate fertilizer could be saved as in Niger(Guizotia abyssinica)by inoculating Glomusmosseae. Zinc is a vital micronutrient for many plants but its excess can be calamitous.AMF contributes to plant Zn uptake but their role in the edible portion of the crop has not been studied yet. The mycorrhizal pathway of Zn uptake contributed up to 24.3% of the total above-ground Zn in wheat and up to 12% of that Zn in Barley. The greatest contribution by the mycorrhizal pathway was observed in Barley at the lowest Zn addition and in wheat at the .highest one. Besides the grain yield of bread wheat was increased by AMF.

An application of mycorrhiza has a role in achieving the goal of food security. The establishment of the mycorrhiza in soil and their pre-adaptation steps affect food for the growing billions. Nowadays, the use of arbuscular mycorrhizal fungi (AMF) in the agricultural field as biofertilizer is on the rise. Zinc (Zn) is one of the important elements for crop growth and development and possesses negative interaction with excess applied phosphorous (P). An estimation of 50% of the world's cereal growing soils is considered to be low in plant-available Zn. More than 33% of the world population is affected by Zn deficiency. The two different pathways for the uptake of P and Zn from the soil are mycorrhizal pathway uptake (MPU) and direct pathway uptake (DPU). The contribution of Zn by MPU and DPU varied in small quantities (i.e., in μg). In this regard, 24% of the Zn has transferred through the MPU pathway. This type of result has important implications in plants grown with low Zn concentration and high phosphorous application. Under high soil Zn concentration, there is little influence of MPU over DPU. MPU is active when soil Zn supply is low. An important repercussion for crop growing in Zn deficient soil. The relative contribution by the MPU was reduced in huge amounts while the activity of DPU increased with increasing soil Zn supply. Furthermore, a comparative study between mycorrhizal and non-mycorrhizal plants cannot tell us about the activity and interplay between MPU and DPU. An independent study is required to draw valid conclusions. Therefore, it can be concluded that the interplay between DPU and MPU of Zn and P is highly complex and due attention has to be paid for future research. Furthermore, the balanced use of MPU for the soil Zn and P is highly recommended.

Field screening of eleven most popular jute varieties belonging to Corchorus olitorius species was done against the major pests in the farm of Jute Research Programm, Itahari, Sunsari, Nepal during 2017 and 2018. Different species of pests belonging to insects, mites and nematodes were found feeding on jute. Among them, jute Semilooper (Anomis sabulifera Guen.), Bihar hairy caterpillar (Spilarctia obliqua Wlk.), yellow mite (Polyphagotarson emuslatus Banks), are causing economic damage to the jute crop. Eleven jute varieties were selected to conduct varietal preference and tested against major pest of jute in field condition. Among the eleven varieties JRO-524 was found to be moderately resistant against the Semilooper (A. sabulifera) and Bihar hairy caterpillar (S. oblique) but least susceptible to yellow mites. Likewise, the variety KEN-DS-058, KEN-DS-066, BJRI-1965 and BJRI-1968 showed highly susceptible to major pest Semilooper (A. sabulifera), Bihar hairy caterpillar (S. oblique) and yellow mites. The variety BRD-SRB-061, YA-41, O-4, KEN-BL-130, Itahari-2 showed moderate resistance to Semilooper (A. sabulifera), Bihar hairy caterpillar (S. oblique) but moderately susceptible to yellow mites. Further, the fibre production capacity of the varieties under different pest’s pressure was found relatively higher in variety JRO-524 followed by YA-41, BRD-SRB-061, KEN-BL-130 and O-4 respectively. The relatively higher yield recorded under varying pest levels over two consecutive seasons is an indicative of greater field tolerance of olitorius jute varieties.

Large cardamom is one of the most important spices that can significantly contribute to the economical farming in the country of Nepal. It is grown in Nepal and north-eastern states of India which provide suitable agroclimatic growing conditions of high humidity, ambient temperature and high rainfall. Meeting the demand for high quality plants and yield of cardamom is challenging with traditional methods of propagation. The present study has used the plant tissue culture technique to produce high quality plants. In this regard, MS media with three different hormonal combinations were used for the development protocol for 8 weeks. Shoot length, root length, shoot number and root number were assessed at intervals. The best protocol for growth was MS media with 1 mg/L BAP + 0.5 mg/L IBA for the Ramsey variety, with no significant difference for Golsai, Dambarsai, or Sikkimae varieties. Similarly, the acclimatization and field transfer study was done. The use of any substrate composition in ratio of coco peat: soil 1:2; moss: coco peat 1:2 and sawdust: coco peat 1:2 enables transfer of healthy plants to the field. The results indicate that the varieties respond differently to the micropropagation process and to hormone concentrations indicated by differing root and shoot production. The protocol of 1mg/L BAP and 0.5mg/L IBA could be used for the Ramsai while optimal shoot production for Golsai and Sikkimae should be at 0.5mg/L and 5mg/L for shoot production. All varieties showed optimal root production at 0mg/L BAP and 0.5mg/L IBA. This study sheds light on the different responsiveness of varieties to tissue culture and hormone concentrations for both root and shoot development in micropropagation.