Use of Varieties to Minimise Losses from Sugarcane Diseases in South Africa

The current low incidence of sugarcane diseases in the South African sugar industry has been hardwon. This achievement is due largely to the selection and release of resistant varieties. Consequently, current estimates of crop loss due to smut and mosaic indicate reductions in yield of only 0.2% in total, equivalent to R7 million per annum. In the absence of an RSD variety resistance screening method, the incidence of this disease has been reduced via the use of RSD-free seedcane and the employment of field hygiene measures. Loss due to RSD is estimated at 0.3% of yield, equivalent to R10 million per annum. The continued control of other important sugarcane pathogens is based on selecting and releasing varieties with satisfactory resistance. The benefit of growing sugarcane varieties that minimise losses from diseases can be demonstrated by quantifying the effect of diseases on susceptible varieties.