Optimization of process parameters for synthesis of 2, 4,6,8,10,4,6,8,10, of desired particle size have been described. CL-20, the most powerful high explosive, is being synthesized at the High Energy Materials Research Laboratory (HEMRL, Pune, India) by nitration of 2,6,8,4,6,8,10,. Nitration of TAIW is a mild exothermic reaction. Although information on synthesis of CL-20 is reported, no information is available on process optimization. In order to optimize the process parameters for synthesis of CL-20 to obtain higher yield and purity, a study was carried out with variation of different parametric conditions like temperature, time, concentration of nitric acid, mole ratio of reactants, quantity of solvent=anti-solvent, etc. The effect of each parameter was studied by keeping other parameters constant. In the present study it was found that for $85% yield, optimized temperature envelope was 72-85 C, nitric acid concentration range from 98 to 92%, reaction time was 1 h, and temperature during the addition of TAIW into the mixed acid was 25-40 C. In order to improve the particle size of CL-20, during the recrystallization process, the effect of parameters like addition rate of anti-solvent and rate of agitation were studied and

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An experiment was conducted to evaluate the yield performance of potato varieties with chemical and organic fertilizer at Chilime, Rasuwa. The experiment consisted of eight treatment combinations laid out in two factors Randomized Complete Block Design (RCBD) with three replications. Four potato varieties (Khumal-Seto-1, Khumal-Ujjwal, Janak-Dev and Kufri-Jyoti) with fertilizer (Recommended dose of chemical fertilizer (100:100:60 NPK kg ha-1) and organic farmyard manure (15 mt ha-1) were used to make eight treatment combinations. The results showed that Janak-Dev had the highest plant height (69.3 cm) and canopy diameter (60.92 cm). Khumal-Seto-1 had highest number of main stems per hill (3.75) which were statistically similar to Kufri-Jyoti (3.42) and Khumal-Ujjwal (3.25). Janak-Dev had the lowest number of main stems per hill (1.87). The effect of fertilizer was nonsignificant. Flowering occurred earlier in Janak-Dev at 61.17 days after sowing while Kufri-Jyoti flowered after 73.17 days after sowing. The highest number of tubers were found in Khumal-Seto-1 (9.167) and lowest in Janak-Dev (5.750). Number of tubers per plant was not affected by types of fertilizers used. Maximum weight of each tuber (107.7 grams), yield per plant (780 grams) and yield per hectare (37.1 mt ha-1) were obtained from Kufri-Jyoti. These parameters were the highest from chemical fertilizer application. This field experiment showed that Kufri-Jyoti with recommended dose of chemical fertilizer was appropriate to get optimum yield under Chilime condition. SAARC J. Agric., 19(1): 103-112 (2021)

AbstractA field experiment was carried out in sub-tropical climate of Bhimdattanagar, Kanchanpur to assess the effect of site specific nutrient management approach in productivity of spring rice. The experiment was carried in single factor randomized completely block design with four replication, in four different farmer’s field, each farmers’ field as single replication. The seedlings were grown in the mat nursery bed and transplanted in the experimental plots with different nutrient management practices. Nutrient management practices were Site Specific Nutrient Management with Nutrient Expert dose (SSNMNE)(109:28:38 kg NPK/ha), Government recommendation dose (100:30:30kg NPK/ha +6 ton FYM), Farmer’s field practice (FFP)(different among farmers) with three omission plots viz. omission of Nitrogen (0:28:38 kg NPK/ha), Omission of Phosphorus (109:0:38 kg NPK/ha) and Omission of Potassium (109:28:0 kg NPK/ha). SSNM-NE dose was obtained by household survey in the respective area and using nutrient expert model. The growth parameters, yield, yield attributing traits and total cost of production were recorded. Data were analyzed using Duncan’s Multiple Range Test (DMRT) in Genstat. Result indicates that the highest grain yield (5.81 t/ha) was obtained from SSNM-NE which was statistically at par with government recommendation (5.54 t/ha). Similarly, thousand grains weight, straw yield in the experiment 23.20g, 6.90t/ha were significantly higher in SSNM-NE respectively. Straw yield, grain yield and thousand grain weight of SSNM-NE were found to be statistically at par with government recommendation. The economic analysis revealed that higher B: C ratio (1.91), net return and gross return were higher in SSNM-NE.

Maintaining the optimum plant population and competition in field crops right from germination to harvesting is one of the important tasks for efficient utilization of resources and to get highest economical yield. To know the about the inter and intra plant competition and its ultimate response on plant density dynamics, review was done on the topic managing plant population and competition on field crops. It was found that the optimum plant population is highly dependent on the various factors like crop inputs, environmental condition and managerial factors and the competition within and between the crop plants. The optimum plant population for any crop in given locality is usually determined by trial and error method. Managing the input level and environmental condition as well as many agronomical approaches can maintain the plant population to a desired level. Proper method of sowing, using good quality seed and right seed rate, optimum sowing depth, sowing seed in good quality soil, plant size and architecture, proper fertilization and irrigation, gap filling and reseeding, over-seeding and thinning, double transplanting and use of tolerance variety can be used to obtain optimum plant population.