Biological Control of Seed Rot and Preemergence Damping-Off of Chickpea with Penicillium oxalicum. Walter J. Kaiser, Research Plant Pathologist, Regional Plant Introduction Station, USDA, ARS, Washington State University, Pullman 99164. Richard M. Hannan, Biological Technician, Regional Plant Introduction Station, USDA, ARS, Washington State University, Pullman 99164. Plant Dis. 68:806-811. Accepted for publication 26 March 1984. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1984. DOI: 10.1094/PD-68-806.

Seed treatment with conidia of Penicillium oxalicum significantly reduced seed rot and preemergence damping-off of chickpea (Cicer arietinum) caused by Pythium ultimum in two naturally infested soils from the Palouse region of eastern Washington. P. oxalicum was the only biocontrol organism of three tested that consistently enhanced emergence and increased seed yields over untreated seeds under field and greenhouse conditions. Seeds coated with conidia of Trichoderma hamatum or T. harzianum usually were ineffective in controlling the Pythium seed rot. In all tests, plant stands and yields from seeds treated with P. oxalicum as a dust (dry spores) or in a 1.6% methyl cellulose suspension were significantly better than those from untreated seeds and were statistically as effective as captan-treated seeds in field trials at Central Ferry, WA, but not Pullman, WA. Similar plant emergence and seed yields were obtained from P. oxalicum-coated seeds that had been stored for 8 mo or 5 days at 4 C and 35% RH, then planted in the field at Central Ferry, WA. Emergence and yields of metalaxyl-treated seeds were statistically equal or superior to all other treatments in greenhouse and field trials.