Effect of Delayed Harvesting on Maize Ear Rot in Western Kenya

Abstract

Maize ear rot is an important disease in Kenya. Despite causing yield losses the ear rot fungi also contaminate infected grains with mycotoxins. In western Kenya, the leading maize producing region of the country, farmers habitually leave their maize in the field upon maturity so as it may dry, but the harvest season often coincides with the second rains and the result is often increased rotting. Using on farm experiments in farmers’ fields with 12 farmers at both Malava and Tongaren in Westen Kenya. Ten varieties were planted and harvested at 4, 8 and 12 week harvest time points after physiological maturity. Four farmers from every region were randomly selected at each harvest time point and their crop harvested. Relevant data that included percentage rotten grain, ear rot incidence, severity, borer incidence, lodging and drooping of ears was collected. The results showed that delayed harvesting increases ear rotting. Many ear rot resistance traits like closed ear tips, hard to lodge stems, drooping ears and resistance to insects were compromised when maize was left in the farm for longer periods of time. Farmers are therefore advised to harvest their maize at four weeks after physiological maturity to avoid further rotting and possible lethal contamination of grains by mycotoxins