Effect of Pachymetra Root Rot on Sugarcane Yield. R. C. MAGAREY, Bureau of Sugar Experiment Stations, P.O. Box 566, Tully, Queensland, Australia. Plant Dis. 78:475-477. Accepted for publication 27 October 1993. ©1994. Copyright 1994The American Phytopathological Society. DOI: 10.1094/PD-78-0475.

The effect of Pachymetra root rot on yield of sugarcane was assessed through a correlation of soil inoculum density with yield in the susceptible cultivar Q90. Variation in plot inoculum density was created by growing cultivars of varied resistance in the previous crop. Yield loss in the plant crop was estimated at 33% and in the first ratoon at 37%. Pachymetra root rot significantly reduced stalk number and stalk weight in both the plant and first ratoon crops but not stalk sugar content. Pachymetra root rot is probably a significant component in northern poor root syndrome of sugarcane.