Yada B., Tukamuhabwa P., Alajo A., Mwanga R.O.M.
National Agricultural Research Organization, National Crops Resources Research Institute, Namulonge, P.O. Box, 7084 Kampala, Uganda; Department of Crop Science, Makerere University, P.O. Box, 7062, Kampala, Uganda
Yada, B., National Agricultural Research Organization, National Crops Resources Research Institute, Namulonge, P.O. Box, 7084 Kampala, Uganda, Department of Crop Science, Makerere University, P.O. Box, 7062, Kampala, Uganda; Tukamuhabwa, P., Department of Crop Science, Makerere University, P.O. Box, 7062, Kampala, Uganda; Alajo, A., National Agricultural Research Organization, National Crops Resources Research Institute, Namulonge, P.O. Box, 7084 Kampala, Uganda; Mwanga, R.O.M., National Agricultural Research Organization, National Crops Resources Research Institute, Namulonge, P.O. Box, 7084 Kampala, Uganda
A total of 946 morphologically distinct accessions of sweetpotato {Ipomoea batatas [L] Lam) germplasm collected from Uganda were evaluated along with four released cultivars for root yield, dry matter, sweetpotato virus disease (SPVD) and Alternaria bataticola blight disease resistance for two seasons; 2005B (September 2005 to January 2006) and 2006A (April to August 2006) at three sites for selection of superior genotypes. The genotypes differed significantly in yield, dry matter content, SPVD and Alternaria blight resistance (p=0.05). Genotype SPVD severity ranged from 1.0 to 5.0 with an overall mean of 2.6. Alternaria severity scores ranged from 1.0 to 5.0 with an overall mean of 2.2. Total root yields ranged from 0.0 to 52.5 t ha -1 with an overall average of 20.3 t ha -1. Most genotypes had mean total root yields of less than 15.0 t ha -1, low specific gravity values of less than 2.0, and low disease resistance. A positive correlation was observed between SPVD and Alternaria blight (r=0.33), while both diseases were negatively correlated with yield traits. A total of 192 superior genotypes were selected for further evaluation and use for variety development in hybridization schemes.