Groundnut Arachis hypogaea L. is an important crop both in subsistence and commercial agriculture in arid and semi-arid regions of the world. Leaf spot diseases caused by fungus have been a major destructive disease of groundnut and could cause a yield loss of up to 50 % or more. Twenty five groundnut genotypes along with local checks (B -4 and Jayanti) were collected and an experiment conducted during 2010 and 2011at National Oilseed Research Program (NORP), Nawalpur, Sarlahi, Nepal. The experiment was conducted to study their level of variability to cercospora leaf spot diseases tolerance in a randomized complete block design (RCBD) with 3 replications. The objective of the study was to determine the reaction of different groundnut genotypes to cercospora leaf spot diseases to create basis for selection for the disease tolerance. The analysis of variance (ANOVA) indicated highly significant difference among the groundnut genotypes for the traits days to 75% flowering, days to maturity, 100 kernel weight and cercospora leaf spot score. The results indicated that the genotype ICGV-91074, ICGV-88473, ICGV-92173, B-4, Rajashri, ICGV-91104 and ICGV-98089 had the lowest level of cercospora leaf spot disease incidence. The genotypes ICGV-91074, ICGV-98089, ICGV-92173 and ICGV-88473 produced the highest pod yield also had the lowest cercospora leaf spot incidence. The genotypes ICGV-91104, ICGV-92173, B-4 and ICGV-91074 produced the highest haulm yield had the lowest cercospora leaf spot incidence. The study found the remarkable level of variability existing among the groundnut varieties that is essential in groundnut improvement. This study recommends that development or selection of tolerant genotypes to leaf spot disease should be based on their level of incidence. This will be the only effective measure in decreasing production costs and protect the environment from pollution. Therefore potential genotypes exist for selection among the evaluated groundnut genotypes for cercospora leaf spot disease tolerance.
Keywords:Groundnut, leaf spot, cercospora, tolerance, incidence