Cotton verticillium wilt control with soil fumigation
Stephen Wilhelm, University of California
R. C. Storkan, Trical, Inc.
James E. Sagen, University of California
Alan G. George, Tulare County
Helga Tietz, University of California
California Agriculture 26(10):4-6. DOI: 10.3733/ca.v026n10p4.
A detailed study of both individual cotton plants and data from the overall performance of large fumigation plots, resulted in convincing evidence that early season infection by Verticillium wilt may drastically reduce yield. Yield reductions were reflected in reduced production per plant and in bolls of lighter weight. Where infection of individual plants occurred from seedling to harvest, and occurred more severely on some plants than on others, yield reductions resulted from the production of fewer bolls per foot of row, and lighter boll weight averages. Fumigation obviously controlled soil-borne pathogens other than Verticillium—some perhaps unknown—so the total effect of fumigation evidenced in the second year may not have resulted from Verticillium wilt control alone. High plant vigor and dense plant populations undoubtedly reduced yields in fumigated plots.
Stephen Wilhelm is Professor, Department of Plant Pathology, University of California, Berkeley; R. C. Storkan is President of Trical, Inc., Morgan Hill; James E. Sagen is Staff Research Associate, University of California, Berkeley; Alan G. George is Farm Advisor, Tulare County. Helga Tietz is Assistant Specialist; Department of Plant Pathology, University of California, Berkeley.