Diseases of Sugarcane and their Control in Puerto Rico

Abstract

A sugarcane disease survey was conducted over different mill zones of Puerto Rico during the fall of 1969 and the spring of 1970. It covered the plantations of 10 sugar mills. The results obtained to date indicate that the diseases of major importance are ratoon stunting, chlorotic streak, pineapple disease, and root rot caused by a complex of Pythium, Fusarium and nematodes. The specific disease problems are identified in each area. Special attention was given to disease distribution, economic importance, and possible methods of control. Although in general low incidence of ratoon stunting was observed in commercial plantings, data obtained from previous variety tests indicate this malady to be potentially dangerous. Hot water treatment of seedpieces should be conducted to prevent its further spread. The significance of chlorotic streak disease as a factor in yield decline in Puerto Rico has not yet been completely evaluated. The high incidence of this disease, under present conditions, has given rise to concern. Pineapple disease caused by Thielaviopsis paradoxa greatly affects the germination of P.R. 980, especially in areas with poor drainage. Root rots caused by Pythium, Fusarium and nematodes reduced germination of P.O.J. 2878 and H. 328560 by as much as 40 percent in poorly-drained areas.