Papers by Baidya Nath Mahto
Field Crops Research, 2006
Spot blotch, caused by Cochliobolus sativus, is a serious disease constraint to wheat (Triticum a... more Spot blotch, caused by Cochliobolus sativus, is a serious disease constraint to wheat (Triticum aestivum L.) yields under rice-wheat systems in the lowlands of South Asia. The surface seeding of wheat, which is becoming popular as a resource conserving technology on resource-poor farms, might provide a more conducive environment for early foliar blight development. During 2002 and 2003 wheat growing seasons, replicated studies were conducted in farmers' fields in Nepal to determine the effects of surface seeding in comparison with conventional seeding on foliar blight development and agronomic performance, using the wheat varieties Rohini, BL 1473, Bhrikuti, and a farmer variety. The experiment was conducted in a strip-plot layout with strips of wheat varieties and fungicide treatments (sprayed or unprotected) in a randomized block with three replicates. The area under the disease progress curve (AUDPC) was estimated using multiple foliar blight assessments on flag leaf (AUDPC-FL) and on whole plants (AUDPC-WP). Grain yield, thousand-kernel weight (TKW) and kernels per spike (KPS) were also evaluated. Conventional tillage and surface seeding differed significantly for AUDPC, grain yield, TKW and KPS. In the fungicide-unprotected plots, the AUDPC-FL and AUDPC-WP values were, respectively, 8 and 34% higher under surface seeding than conventional tillage. On average, surface seeding produced 25% higher grain yield, 1.3 g higher TKW, and 1.8 more KPS than conventional tillage. The four wheat varieties differed significantly for all traits under both conventional tillage and surface seeding. The average foliar blight induced reductions in grain yield, TKW, and KPS were 16, 12, and 15%, respectively, under conventional tillage. The corresponding reductions were 23, 13, and 19% under surface seeding. Rohini produced the highest grain yields under both conventional tillage (2.67 t ha À1) and surface seeding (3.58 t ha À1). Under both seeding systems, Rohini showed the highest and BL 1473 the lowest grain yield reductions due to disease. Despite a higher spot blotch severity, the higher grain yield under surface seeding is suggestive of its adoption on wetlands under rice-wheat cropping systems. The four varieties responded differently to the tillage methods' effect on spot blotch severity and grain yield, suggesting the importance of tillage method in cultivar selection when considering the effect of microenvironment on susceptibility to foliar diseases. The findings have implications for foliar blight management using surface seeding as a resource conservation technology in the warm regions of South Asia.
European Journal of Plant Pathology, 2011
Abstract Fungal leaf spot diseases of wheat (Triticum aestivum L.) in Nepal cause significant yie... more Abstract Fungal leaf spot diseases of wheat (Triticum aestivum L.) in Nepal cause significant yield reduction. Although field testing has identified a few partially resistant cultivars, most wheat grown in Nepal lacks adequate resistance to leaf spot diseases. During 20092010 ...
Evaluation of 45 wheat genotypes was performed to quantify genetic responses to inoculation of ru... more Evaluation of 45 wheat genotypes was performed to quantify genetic responses to inoculation of rust pathogens in aqueous suspension at the early vegetative stage. The study was conducted in field conditions at Plant Pathology Division, Nepal Agricultural Research Council, Lalitpur, Nepal in winter, 2013. Results showed large variations of rust resistance on wheat genotypes. Thirty-six genotypes were susceptible to yellow rust (YR), 18 had high severity, 7 had moderate severity, 6 had low severity, 5 had trace reactions, while 9 were rust-resistant. Old varieties (Lerma-52, Kalayansona, RR-21, NL-30, HD-1982, UP-262, Lumbini, Vinayak, Vaskar, Nepal-297, Nepal-251, BL-1135, Annapurna-4, Achyut, Rohini, and BL-1473) had high severities of YR, but relatively recent cultivars had medium severities. YR was severe (100S) in genotypes HD-1982, Vaskar, Vijay, and Rohini followed by RR-21, NL-30, UP-262, Nepal-297, BL-1135, and Annapurna-4 (90S). The pipeline cultivars: Aditya, NL-971, BL-350...
Leaf rust, caused by Puccinia triticina. is an economically important wheat disease which occurs ... more Leaf rust, caused by Puccinia triticina. is an economically important wheat disease which occurs in all the river basin and plain areas of Nepal. Ninety-nine wheat lines that included most of the released genotypes and new advanced breeding lines were subjected to multi-pathotype evaluation of P. triticina both at seedling and adult plant stage at Directorate of Wheat Research (DWR), Shimla, India. Sixteen pathotypes of the pathogen were used for seedling evaluation while the two most predominant pathotypes, 121R63-1 (THTTS) and 21R55 (PHTTL) were used to screen for adult plant resistance (APR). In addition, SSR marker csLV34_Lr34sp was also used for identifying Lr34 gene in these lines. Thirty-five lines were susceptible at seedling and adult plant stages. Different combinations of seven resistance genes, viz Lr1, Lr10, Lr13, Lr19, Lr23, Lr26 and Lr34 were characterized by applying the gene matching technique. The most commonly detected gene was Lr13 (37% of the tested lines), foll...
Journal of Nepal Agricultural Research Council
Pest Risk Analysis (PRA) is the process of evaluation for biological and economic evidences in or... more Pest Risk Analysis (PRA) is the process of evaluation for biological and economic evidences in order to determine whether a pest should be regulated under phyto-sanitary measures. The present mini review highlights the potential potato pathogen list recorded in Nepal harmful for potato production and productivity. At global scale altogether 135 potential quarantine pests (PQP) for potato has been recorded, while in Nepal only 92 PQP were recorded. Out of those 52, 13 and 27 were fungi, bacteria and viruses respectively. Among the 92 PQP, 34, 30 and 13 were considered at high, medium and lower risk type pathogens for potato. There was no information available on other 15 PQP.
Journal of Nepal Agricultural Research Council, May 8, 2017
Pest Risk Analysis (PRA) is the process of evaluation for biological and economic evidences in or... more Pest Risk Analysis (PRA) is the process of evaluation for biological and economic evidences in order to determine whether a pest should be regulated under phyto-sanitary measures. The present mini review highlights the potential potato pathogen list recorded in Nepal harmful for potato production and productivity. At global scale altogether 135 potential quarantine pests (PQP) for potato has been recorded, while in Nepal only 92 PQP were recorded. Out of those 52, 13 and 27 were fungi, bacteria and viruses respectively. Among the 92 PQP, 34, 30 and 13 were considered at high, medium and lower risk type pathogens for potato. There was no information available on other 15 PQP.
Plant Disease, 2013
Spot blotch, caused by Cochliobolus sativus, is a devastating foliar disease of wheat in Nepal an... more Spot blotch, caused by Cochliobolus sativus, is a devastating foliar disease of wheat in Nepal and in the Northern Great Plains of the United States. However, limited information on variation in virulence and genetic structure of C. sativus from wheat is available. In this study, pathogenic variation of 96 isolates of C. sativus from the Hill and Plain areas in Nepal (n = 48) and in the Central and Northern areas in North Dakota (n = 48) were evaluated on 12 differential wheat lines. DNA polymorphisms in all isolates were analyzed using eight selected amplified fragment length polymorphism primer combinations. Phenotypic data analysis showed the isolates varied greatly and were classified into 47 pathotypes. Cluster analysis indicated the isolates fell into three distinct groups with low, intermediate, and high virulence. Population genetic analysis revealed significant linkage disequilibrium ([Formula: see text] = 0.066 to 0.292), indicating that sexual reproduction plays little or...
Plant Disease, 2013
Spot blotch, caused by Cochliobolus sativus, is a devastating foliar disease of wheat in Nepal an... more Spot blotch, caused by Cochliobolus sativus, is a devastating foliar disease of wheat in Nepal and in the Northern Great Plains of the United States. However, limited information on variation in virulence and genetic structure of C. sativus from wheat is available. In this study, pathogenic variation of 96 isolates of C. sativus from the Hill and Plain areas in Nepal (n = 48) and in the Central and Northern areas in North Dakota (n = 48) were evaluated on 12 differential wheat lines. DNA polymorphisms in all isolates were analyzed using eight selected amplified fragment length polymorphism primer combinations. Phenotypic data analysis showed the isolates varied greatly and were classified into 47 pathotypes. Cluster analysis indicated the isolates fell into
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Papers by Baidya Nath Mahto