Field experiments were conducted in Cameroon in 1995 and 1996 to evaluate reactions of different potato genotypes to late blight. There were significant differences among genotypes for tuber yield, late blight readings and earliness. The application of fungicides significantly increased potato yield but had a non significant effect on the damage due to foliage blight (Phytophthora infestans). The limited effect of fungicide treatment was because the late blight severity was so high that the eight fungicide applications could not provide sufficient level of disease control and/or the persistence rain throughout the growing season might have washed-off the applied fungicide, thus decreasing its effect. There was a significant year effect on the yield. The fifth late blight reading (LB5) was more related to yield than the later readings suggesting that the damage caused by the disease at an earlier stage of plant development contributed most to yield reductions. Several advanced genotypes had similar or superior performance to that of CIPIRA and TUBIRA released in Cameroon in 1992.
Key Words: Cameroon, Phytophthora infestans, potato yield, Solanum tuberosum
(African Crop Science Journal 2001 9(1): 209-214)