EARLY-SEASON SPRAYS FOR CONTROL OF COFFEE BERRY DISEASE

Bock (1963) showed that in the years 1956‐60 early season sprays achieved good control of coffee berry disease (CBD) in East Rift areas of Kenya. In recent years, however, this spray programme has given erratic and often very poor results. In field experiments in 1966 yields of main (late) crop were increased from 151 to 652 kg/ha by early season sprays but in 1967 practically no control of the disease was achieved. Of the fungicides examined captafol was superior to copper; ‘Tuzet’, the best antisporulant, gave the poorest control. Analysis of the data indicates that this large seasonal variation depends on the very different inter‐relationships between rainfall, cropping pattern and timing of sprays which obtained in the 2 years. The hypothesis that early‐season sprays achieve control of CBD mainly by reducing the sporulating capacity of the maturing bark is questioned. The view is put forward that the protectant action of these sprays has been underestimated. Copyright © 1969, Wiley Blackwell. All rights reserved