EPIDEMIOLOGICAL ASPECTS OF COTTON RAMULOSIS (Colletotrichum gossypii SOUTH. Var. cephalosporioides COSTA)

Abstract

These experiments deal with the effects of outbreak of early, medium and late developing ramulosis on the IAC-13.l variety of cotton, which was seeded at three different intervals in Itauçu (Goiás—Brazil). The effects of the ramulosis on the height and weight of the plants, on the number of bolls, and on the weight of the cotton seeds and lints, were studied. The experiments were installed in a flat area of red latosoil. The experimental design was one of random blocks with six repetitions and the plants were classified, at the end of their vegetative growth, into the following categories: healthy, early ramulosis, medium ramulosis and late developing ramulosis. The early and medium ramulosis affected more significantly the studied parameters, and it was observed that varieties of cotton which were moderately resistant in relation to ramulosis, can be severely affected during growing seasons of heavy rains such as the 1975/76 season.