Relation of temperature to infection of bean and cowpea seedlings by Rhizoctonia bataticola

Abstract does not appear. First page follows.

Kendrick⁽⁶⁾ has described a serious seedling blight of beans (Phaseolus vulgaris L.) occurring in the Sacramento Valley and delta region, caused by the fungus, Rhizoctonia bataticola (Taub.) Butler. He showed that the disease was favored by high temperatures during the period of seedling emergence and observed that cowpeas (Vigna sinensis L.) under similar conditions appeared to escape infection. In order to learn more about the temperature relations, the mode of infection, and the apparent resistance of cowpeas, cultures of Rhizoctonia bataticola (Taub.) Butler isolated from various hosts have been compared as to cultural characters and effect of temperature on growth and pathogenicity to bean and cowpea seedlings.

Sources of Cultures

The cultures of Rhizoctonia bataticola from beet were isolated from a root-rot of sugar beet—A, B, and C, from beets collected near Walnut Grove, California; D and E near Marysville; and F near Stockton. The cultures from bean (A, B, C) were isolated by J. B. Kendrick from bean seedlings—A and B at Davis, C near Lodi. The culture from cowpea was isolated from herbarium specimens of older diseased Blackeye cowpea plants collected at Modesto, California, by W. W. Mackie. The two cultures from sweet potato were isolated from a rot of sweet potatoes near Atwater, California. The culture from begonia was supplied by M. R. Harris of the California State Department of Agriculture. The culture from citrus was supplied by H. S. Fawcett, Riverside.