SUMMARYThe effects of copper, captafol and Tuzet, applied to coffee in early season (January to April) and in other programmes continuing through the long rains (January to July), on the bark populations ofColletotrichum cofleanumNoack. (the pathogenic CBD strain and the saprophyticccm, ccaandccpstrains),Phomaspp.,Fusarium stilboidesWollenw. and aPhomopsissp. were investigated on branch material from field experiments in Kenya in 1968 and 1969 by a plating technique which estimated sporulating capacity (s.c.)Fungicide application initially caused a non‐specific reduction in s.c., Tuzet being the most effective. With the onset of the long rains this general reduction was not maintained, although during the period between the long and short rains the levels of many fungi in sprayed plots were still below those in the unsprayed control. In contrast, the s.c.of Phomain plots sprayed with copper and ofPhomopsisin those sprayed with Tuzet were higher than on unsprayed plots. The S.C. of the CBD strain was below that in the control only in plots sprayed with captafol.Effects were still evident after the short rains. Some early‐season programmes of all three fungicides increased the s.c. of the CBD strain while continuing programmes of copper and captafol reduced its S.C. relative to that on unsprayed trees. Differences in S.C. at this time were related to infection in the early crop a few weeks later.The initial antisporulent effect of a fungicide appears less important than its persistence and its effect on bark colonization by the different fungi. Early‐season sprays of copper, formerly used to control CBD, may have contributed to an increase in disease hazards by affecting the primary level of the pat