VIEW ARTICLE

Growth Response of Sclerotium rolfsii to the Herbicide EPTC in Liquid Culture and Soil. R. Rodriguez- Kabana, Assistant Professor, Department of Botany and Plant Pathology, Auburn University Agricultural Experiment Station, Auburn, Alabama 36830; E. A. Curl(2), and J. L. Peeples(3). (2)(3)Professor of Plant Pathology, and Graduate Assistant, respectively, Department of Botany and Plant Pathology, Auburn University Agricultural Experiment Station, Auburn, Alabama 36830. Phytopathology 60:431-436. Accepted for publication 1 October 1969. DOI: 10.1094/Phyto-60-431.

Effect of the herbicide EPTC (ethyl-N,N-dipropyl-thiolcarbamate) on growth of Sclerotium rolfsii was determined in liquid and soil cultures. In modified Czapek’s solution, mycelial production was inhibited by all concentrations of the herbicide (10, 25, 50, and 100 µg/ml), inhibition being directly proportional to concentration. A corresponding decline in utilization of glucose, NO₃-N and inorganic phosphate (Pi) was observed. Increase in titratable acidity of the culture medium at the two highest herbicide concentrations, and an increase in the ratio relating glucose consumed in Pi uptake, suggested a possible action of the herbicide in the respiratory cycle of the fungus. In soil cultures containing 0, 1.0, 2.5, 5, and 10 µg of EPTC/g, growth of S. rolfsii was measured in terms of saccharase activity. Enzyme activity increased at herbicide concentrations of 5 and 10 µg/g. The ratio of saccharase activity to glucose that was removed increased with increasing herbicide concentration.