Nutrient Management for Higher Productivity of Swarna Sub1 Under Flash Floods Areas

Two field experiments were conducted at Regional Agricultural Research Station, Tarahara, Nepal during 2012 and 2013 to determine the effect of agronomic management on growth and yield of Swarna Sub1 under flash floods. The first experiment was laid out in a split plot design with three replications; and four different nutrient combinations at nursery as main plots and three age groups of rice seedlings as sub plots. The second experiment was laid out in a randomized complete block design and replicated thrice; with three post flood nutrient doses at six and 12 days after de-submergence (dad). The experiments were complete submerged at 10 days after transplanting for 12 days. The survival percentage, at 21 dad, was significantly higher in plots planted with 35 (90.25%) and 40 (91.58%) days-old seedlings compared to 30 days-old seedlings (81.75%). Plots with 35 days-old seedlings produced 5.15 t ha-1 with advantage of 18.83% over 30 days-old seedlings. Plots with 100-50-50 kg N-P2O5-K2O/ha at nursery recorded the highest grain filling of 79.41% and grain yield of 5.068 t/ha with more benefit. Post flood application of 20-20 N-K20kg/ha at 6 dad resulted in higher plant survival and taller plants, leading to significantly higher grain yield of 5.183 t/ha and straw yield of 5.315 t/ha. Hence, 35-40 days old seedlings raised with 100-50-50 kg N-P2O5-K2O /ha in nursery and the additional application of20-20 kg N-K2O /ha at 6 dad improved plant survival and enhanced yield of Swarna Sub1 under flash flood conditions. The practice has prospects of saving crop loss with getting rice yield above national average yield leading to enhanced food security in the flood prone areas of Nepal

Yield Interactions of Wheat Genotypes to Dates of Seeding in Eastern Mid Hills of Nepal

Wheat (Triticum aestivum L.) is one of the major cereal crops and staple food sources in Nepal. Wheat varieties being popular in mid hill regions are still in the early stages of adoption. Identification of appropriate date of seeding plays important role in enhancing the adoption rate ensuring the sustainable production. Therefore, three dates viz 15th November, 1st and 15th December for seeding and twenty eight wheat genotypes were evaluated in a split plot design with two replications for two consecutive seasons in 2011/12 and 2012/13 at an altitude of 2200 masl of eastern Nepal. The results showed genetic differences and interaction effect of genotypes with the dates of sowing on grain yield, panicle length and effective tillers per square meter. The wheat sown on 1st December showed the highest yield as compared to other sown dates. Similarly, WK1907, WK1911, WK1803, WK1915, WK1909, WK1714 and WK1803 produced highest yield among the tested genotypes with retaining maximum number of effective tillers and posed suitable maturity across all sowing date.Journal of Nepal Agricultural Research Council Vol.1 2015 pp.33-3

Response of Wheat Genotypes to Different Levels of Nitrogen

A field experiment was conducted using six genotypes of wheat (Triticum aestivum L.) for response to different levels of nitrogen (N) use. The experiment was laid out in split plot design with four levels (0, 50, 100 and 150 kg N ha-1) as main plots and six wheat genotypes (BL 3623, BL 3629, BL 3872, NL 1008, NL 1055 and Vijay, a check variety) as sub-plots. Grain yield and other yield components increased linearly in response to N concentrations in both seasons. Only two parameters: days to heading (DOH) and days to maturity (DTM) varied significantly (p ≤ 0.05) among wheat genotypes in both the years. None of the parameters showed interaction effects in both seasons. Vijay showed highest grain yield of 3.12 t ha-1 in 2013 with the application of 100 kg N ha-1, and 3.23 t ha-1 in 2014 with 150 kg N ha-1. Spike length, productive tillers m-2, number of spikes m-2 and test weight were greater with higher N rates. The straw yield of wheat fertilized with 150 kg N ha-1 was the highest in Vijay (4.35 t ha-1) and BL 3872 (4.33 t ha-1), respectively. Vijay with 100 kg N ha-1 produced the highest number of productive tillers m-2 (276.33) in 2013 and 296.00 with the application of 150 kg N ha-1 in 2014

Screening of local, improved and hybrid rice genotypes against leaf blast disease (Pyricularia oryzae) at Banke district, Nepal

Rice (Oryza sativa) is the major cereal crop of Nepal which is being faced by the devastating rice blast disease caused by Pyricularia oryzae Cavara. An experiment was conducted to screen rice genotypes against leaf blast disease under disease conducive upland nursery at Regional Agricultural Research Station (RARS), Khajura, Banke, Nepal during July to November, 2016. A total of 101 rice genotypes (comprising of local, improved and hybrid) including resistant and susceptible check were screened in a randomized complete block design with two replications. Disease scoring was done beginning from the 20th days of sowing by using the disease rating scale 0-9. Amongst the tested 101 rice genotypes, 28 genotypes were found resistant, 15 genotypes were moderately resistant, 16 genotypes were moderately susceptible, 39 genotypes were susceptible and 3 genotypes were highly susceptible to leaf blast. The information revealed from this study could be helpful for rice leaf blast disease management and utilizing these resistant and moderately resistant genotypes for further resistance breeding program

Evaluating the Performance of Rice Genotypes for Improving Yield and Adaptability Under Direct Seeded Aerobic Cultivation Conditions

With the changing climatic conditions and reducing labor-water availability, the potential contribution of aerobic rice varieties and cultivation system to develop a sustainable rice based agri-food system has never been more important than today. Keeping in mind the goal of identifying high-yielding aerobic rice varieties for wider adaptation, a set of aerobic rice breeding lines were developed and evaluated for grain yield, plant height, and days to 50% flowering in 23 experiments conducted across different location in Philippines, India, Bangladesh, Nepal, and Lao-PDR between 2014 and 2017 in both wet and dry seasons. The heritability for grain yield ranged from 0.52 to 0.90. The season-wise two-stage analysis indicated significant genotype x location interaction for yield under aerobic conditions in both wet and dry seasons. The genotype × season × location interaction for yield was non-significant in both seasons indicating that across seasons the genotypes at each location did not show variability in the grain yield performance. Mean grain yield of the studied genotypes across different locations/seasons ranged from 2,085 to 6,433 Kg ha−1. The best-fit model for yield stability with low AIC value (542.6) was AMMI(1) model. The identified stable genotypes; IR 92521-143-2-2-1, IR 97048-10-1-1-3, IR 91326-7-13-1-1, IR 91326-20-2-1-4, and IR 91328-43-6-2-1 may serve as novel breeding material for varietal development under aerobic system of rice cultivation. High yield and stable performance of promising breeding lines may be due to presence of the earlier identified QTLs including grain yield under drought, grain yield under aerobic conditions, nutrient uptake, anaerobic germination, adaptability under direct seeded conditions, and tolerance to biotic stress resistance such as qDTY2.1, qDTY3.1, qDTY12.1, qNR5.1, AG9.1, qEVV9.1, qRHD1.1, qRHD5.1, qRHD8.1qEMM1.1, qGY6.1, BPH3, BPH17, GM4, xa4, Xa21, Pita, and Pita2. The frequency of xa4 gene was highest followed by qAG9.1, GM4, qDTY3.1, qDTY2.1, qGY6.1, and qDTY12.1

Evaluation of Insecticides for the Management of Litchi Fruit and Shoot Borer

Litchi is an important subtropical evergreen fruit crop grown in Nepal, which have high nutritive value and refreshing taste. The Litchi growers are experiencing severe loss every year with the damage caused by several insect pests. Among them fruit and shoot borer Conopomorpha sinensis Bradley (Lepidoptera: Gracillariidae) is the one of the important insect pest. Experiments were conducted at RARS Tarahara on existing litchi orchard in RCBD design with four replication and five insecticides (Azadiractin, Chlorantraniliprole, Flubendiamide, Lambda cyhalothrin, and Dimethoate) with recommended doses in litchi orchard against C. sinensis during 2015 and 2016 AD to find out the efficient one. Among the tested insecticide chlorantraniliprole (18.5% w/w SC) and flubendiamide (39.35% m/m SC) each were found to be most efficient against C. sinensis and could be applied at the rate of 1 ml per 3 liter of water when fruit size was about pea and applied 3 times with 10 days interval.  This result suggested that these two insecticides could be used for the management for C. sinensis. Farmers may reduce the losses and increase their income with the application of these insecticides</jats:p

Estimation of variability and heritability for morphological traits and leaf rust severity in spring wheat

The seed materials were received from National Wheat Research Program, Bhairahawa and field experiment was conducted at Regional Agricultural Research Station Tarahara during 2012 and 2013 in wheat growing season. The topography of the experimental site was 130 masl with sandy loam soil. The trial included 24 wheat genotypes laid out in alpha lattice design in eight sub blocks within two main blocks. The eastern region of Nepal has been facing the problem of sterility caused by different stresses during reproductive growth stage. So we need to develop the early maturing variety with high yielding potential that could escape the reproductive damage from rainfall, hot westerly wind and leaf rust epidemic. In this study, we identified BL3594, NL1026, NL297, BL3978 and NL1140 as early maturing wheat genotypes with 102, 102, 101, 97 and 102 days of maturity, respectively. The genotypes varied significantly for heading days, maturity days, plant height, spikes per meter square, grain per spikes and grain yield ton per hector. The most stable yield producing genotypes were BL3264, BL3535, BL3623, NL1135 and BL3978. The variety BL3978 had maturity duration of 97 days, even earlier than check variety NL297. The genotypes NL1093 and NL1094 had highest grain per spikes although had negative correlation coefficient with panicle length consequently led to the lower yield. The new genotypes like BL3978, BL3594 and NL1140 should be promote as appropriate varieties for terai region of Nepal. DOI: http://dx.doi.org/10.3126/ijasbt.v2i4.11625Int J Appl Sci Biotechnol, Vol. 2(4): 574-578 </jats:p