Performance of Foliar Fungicides on Soybeans in Georgia. D. V. Phillips, Department of Plant Pathology, Georgia Experiment Station, Experiment 30212. Plant Dis. 68:558-560. Accepted for publication 6 March 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-558.

Potential benefits of foliar fungicides on soybeans were examined in a series of 77 experiments over a 10-yr period at several locations in Georgia, using cultivars of different maturity groups planted as a full-season or second crop. Levels of damaging diseases were usually low, and in more than 90% of these experiments, no significant yield increase was obtained from a foliar fungicide. Increases in percentage of germination of harvested seed occurred less frequently than increases in yield. A decreased incidence of disease was measured in 27% of the experiments, but there was no consistent association between reduced disease and increased yield or seed germination. The only consistent effect of applying foliar fungicides was a delay in maturity of the soybeans. Yield, maturity group of the soybean cultivar planted, location, or planting date were of little value in predicting experiments in which a yield increase was most probable. The current low level of usage of foliar fungicides on soybeans in the Southeast seems to be consistent with the benefits to be expected from their use.