No abstract

No abstract

A field experiment was conducted to evaluate the performance of wheat genotypes against spot blotch disease from November 2016 to April 2017. Experimental field was designed in Alpha Lattice Design with 2 replications and 20 genotypes as treatments. Area Under Disease Progress Curve (AUDPC) value, days to heading, days to maturity, plant height, spike per m2, grain per spike, Thousand Kernel Weight (TKW), grain yield were examined. Negative correlation was observed between yield of different genotypes and AUDPC i.e. -0.17322. Genotype BL 4699 and NL 1247 were found to be resistant with AUDPC value 141.7 and 140.6 and yield 3.335MT/ha and 3.604MT/ha respectively. Similarly, genotype BL 4708, NL 1327 and BL 4707 were found to be tolerant with AUDPC value 567.2, 570.6 and 274.6 and yield 3.761MT/ha, 3.642MT/ha and 3.681Mt/ha respectively. So, resistant and tolerant genotypes BL 4699, NL 1247, BL 4708, NL 1327 and BL 4707 could be suggested to incorporate into the breeding program.

Spot blotch caused by Bipolaris sorokiniana is a major disease of wheat in warm and humid regions of Nepal. The fungus has a worldwide distribution but as a pathogen, it is the most aggressive under the conditions of high relative humidity and temperature associated with the low fertility of soils in Nepal. The yield loss due to the disease is very significant in Nepal. This experiment was conducted to identify the genotypes having a good level of resistance against spot blotch. The experiment set was received from CIMMYT comprises 52 entries and arranged in alpha lattice design with two replications in 2017/18 at National Wheat Research Program, Bhairahawa, Nepal, and Regional Agricultural Research Station, Parwanipur, Bara, Nepal. Each plot size was 8 rows of 2 meters long. Three times disease scoring was done in the double-digit method and calculated the Area under the disease progress curve (AUDPC). Other data were analyzed by using R software (4.2.2). Heading days, days to maturity, plant height, number of grains per spike (NGPS), number of tillers per meter square (NTPM), mean AUDPC, thousand-grain weight (TGW), and grain yield were found highly significant. The genotype 8HLBSN47 was found the highest yielder (4996kg/ha) with a 304 mean AUDPC value. Seventeen genotypes (15.3%) found the lowest mean AUDPC, Penultimate leaf AUDPC, Flag leaf AUDPC, and the highest number of tillers per square meter, number of grains per spike, thousand-grain weight, and grain yield. Keywords: AUDPC, spot blotch, genotypes, HLBSN

No abstract

The diversity of agro-environmental conditions among wheatbased farming systems in the mountainous regions of Nepal may favor the development and production of multiple narrowly adapted varieties over a few broadly adapted varieties. Sixteen genotypes were tested using Participatory Varietal Selection (PVS) trials at farmers' fields in three districts in the Kathmandu Valley.Grain yield was the trait most preferred by farmers, followed by tillering, resistance to diseases, drought, and lodging. Farmer selection of optimal genotypes varied over time and location depending on agronomic and climatic pressures, indicating a preference by farmers for growing multiple, narrowly adapted varieties. Production potential of PVS genotypes averaged up to 142% greater than the most widely grown variety, RR21. With farmer participation in the selection process in different agroecological micro-niches of Nepal, both yield potential and yield stability of wheat should increase significantly, thereby providing farmers with the economic means to sustain the current smallscale agriculture suited to the mountainous terrain.

Wheat is a staple crop in Nepal and is the third major cereal crop grown across the country. To improve productivity and increase the number of farmers growing wheat, the Nepal Agricultural Research Council (NARC), since 1962, has been releasing new wheat varieties with higher productivity and disease resistance. Accurate identification of the varieties grown in farmer's fields is critical for assessing the adoption levels and the impact of new varieties. This understanding can change the landscape of the wheat market and the overall vulnerability of the crop to diseases and abiotic stresses. Current methods of identification that rely on farmer description and morphological traits have been associated with ambiguity. The objective of this study was to determine the varietal adoption of wheat in the seven wheat-growing provinces of Nepal using DNA fingerprinting technology. The study revealed that 'Gautam' and 'Vijay' are the most popular wheat varieties planted in the plain areas of Nepal. The area covered in these varieties during the 2018-2019 wheat season was 20.3 and 19.5% respectively. 'WK1204' was popular and mostly planted in the mountainous areas of Nepal during the October-May cropping season. The decommissioned varieties, including 'Pitic62', 'Kalyansona', 'Siddhartha', 'Vaskar', 'Vinayak', and 'NL 251' are still in use by 8% of wheat farmers across Nepal. Almost 38% of the varieties currently grown were released 20 yr ago. The varietal adoption was determined using molecular markers through fingerprinting, and its implications are discussed in this paper.

Stripe rust disease is a major problem for wheat production in the hills of Nepal. To find resistance sources against this disease, 444 and 457 wheat genotypes received from National Wheat Research Program, Bhairahawa in 2018 and 2019 respectively were evaluated at Khumaltar under inoculated high disease pressure field condition. Disease was evaluated at both seedling and adult stages. In 2018, 315 genotypes showed resistance at seedling stage while 89 genotypes were having adult plant resistance (APR). Also, 71 entries showed immune response and 191 were resistant at both stages. Similarly in 2019, 233 genotypes were resistant at seedling stage and 201 were showing APR. Likewise, 35 entries were immune and 208 were resistant at both stages. Wheat genotypes with APR gene(s) can be utilized for developing durable stripe rust resistant varieties in the future. In addition, the genotypes having both stages resistant could also be used as sources of major and minor gene(s) for stripe rust resistance genotypes development in future breeding purposes.