THE INFLUENCE OF ENVIRONMENTAL CONDITIONS ON THE DEVELOPMENT OF THE ANGULAR LEAF‐SPOT DISEASE OF COTTON

Abstract

SUMMARY Experiments carried out in the Rothamsted control chambers on the influence of atmospheric humidity on the angular leaf‐spot disease of cotton, resulting from spray inoculation of young plants, show that high humidities favour the development of the disease. Maximum infection occurs at humidities exceeding 85 per cent, and at humidities below this the degree of infection decreases rapidly. The relation of these results to the experiments on the influence of air temperature is discussed, and it is concluded that the importance of humidity is mainly physical in nature, by affecting the time during which the infection droplets persist.