Temporal development of sorghum anthracnose in Uganda

The temporal characterization of sorghum anthracnose spread from an inoculum source and selection of models to describe the disease progress overtime was the focus of this study. The development of sorghum anthracnose in time on three cultivars was investigated in field plots inoculated with mixtures of strains of Colletotrichum sublineolum at two locations in Uganda in 2007 and 2008. The effect of genotype was used to estimate the infection rate, amount of inoculum at the start of epidemics, final severity of disease and the area under disease progress curves (AUDPC). The linearised logistic was used to describe the temporal disease development from inoculum source. Host genotype significantly affected the progress of foliar anthracnose from the point of inoculation with the increase in anthracnose severity limited to susceptible and moderately resistant cultivars. The rates of disease progress were higher at Makerere University Agricultural Research Institute Kanbanyolo (MUARIK) than at the National Semi Arid Resources Research Institute (NaSARRI). The rate of disease progress was also higher in 2008 but the intercept was lower in 2008 compared to 2007. Host resistance was consistently associated with lower AUDPC values, lower rates of disease progress and with reduced disease severity at crop maturity. This study identified accession MUC007/162 with lower rates of disease progress and low disease severity that can be used a parent in sorghum breeding programs for development of anthracnose resistant varieties.