Assessment of Groundnut (Arachis hypogaea L.) Genotypes for Yield and Resistance to Late Leaf Spot and Rosette Diseases
Khalid Elsiddig Mohammed *
College of Agriculture and Environmental Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda
Emmanuel Afutu
Department of Crop Science, School of Agriculture, College of Agriculture and Natural Sciences, University of Cape Coast, Cape Coast, Ghana
Thomas L. Odong
College of Agriculture and Environmental Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda
David K. Okello
Department of Groundnut Breeding, National Semi-Arid Research Resources Institute, P. O. Box Soroti, Uganda
Ephraim Nuwamanya
National Crops Resources Research Institute (NaCRRI), P. O. Box 7084, Kampala, Uganda
Olupot Grigon
College of Agriculture and Environmental Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda
Patrick R. Rubaihayo
College of Agriculture and Environmental Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda
Patrick Okori
College of Agriculture and Environmental Sciences, Makerere University, P. O. Box 7062, Kampala, Uganda
*Author to whom correspondence should be addressed.
Abstract
Groundnut which is a major staple food crop in Uganda is constrained by late leaf spot (LLS) and groundnut rosette disease (GRD), accounting for major economic yield loss. This study was conducted to identify sources of resistance to LLS and GRD and yield potential of selected groundnut genotypes that could be used in breeding programs. Thirty-eight groundnut genotypes were evaluated at the National Semi Arid Resources Research Institute (NaSARRI)-Serere, Eastern Uganda during the first and second seasons of 2015. The experiment was arranged in randomized complete block design with four replications. The results showed highly significant (P < 0.01) genotype-by-season interaction for most of the traits studied. There were significant differences among the genotypes for 100 seed weight (P < 0.01), and dry pod yield and unshelled sample of 100 pods at P < 0.05. Late leaf spot severity (at harvest), GRD incidence (at 12 weeks) and severity (at harvest) were significantly (P < .01) different and positively correlated with Area Under Disease Progress Curve (AUDPC). GRD severity at harvest showed highly significant (P < 0.001) negative correlation with shelling percentage. Both 100 seed weight and unshelled sample of 100 pod showed highly significant (P < 0.01) negative correlations with LLS at harvest, LLS AUDPC, GRD at 12 weeks, GRD AUDPC, and GRD severity. Genotypes susceptible to both LLS and GRD recorded the lowest 100 seed weight. Nine genotypes (Serenut.2, SGV 0001, SGV 0005, SGV 0006, SGV 0019, SGV 0071, SGV 0082, SGV 0083, and SGV 89751T) showed resistance to both diseases with high yield potential. These genotypes could be used to introgress resistance to both diseases in acceptable cultivars which are susceptible.
Keywords: Arachis hypogaea, mycosphaerella berkeleyi, variability, incidence, severity, breeding