VIEW ARTICLE

Disease Control and Pest Management

Influence of Seed Treatment with Imazalil on Common Root Rot and the Size of the Subcrown Internode of Wheat. S. H. F. Chinn, Research Scientist, Research Station, Research Branch, Agriculture Canada, 107 Science Crescent, Saskatoon, Saskatchewan S7N 0X2, Canada; Phytopathology 68:1662-1666. Accepted for publication 30 May 1978. Copyright © 1978 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-68-1662.

Common root rot ratings of Neepawa wheat grown at two locations from seed treated with imazalil [1-(B-allyloxy-2, 4 dichlorophenethyl) imidazole] at 0.3 g active ingredient/kg seed averaged 5% and 16% for seedlings and mature plants, respectively, as compared to 32% and 51%, respectively, for those from nontreated seed. Seven other fungicides gave no equivalent reduction in disease ratings. In three tests, using a number of wheat cultivars, soils, and treatment rates in the greenhouse, imazalil lowered disease in the wheat seedlings. The level of control increased with dosage. The internodes of mature plants from treated wheat seed in the field experiment averaged 14.7% larger than those from nontreated seed. In one greenhouse test they averaged 12.8, 27.2, and 37.1% larger, respectively, than those from the nontreated seed, when dosages of 0.1, 0.2, and 0.3 g a.i./kg seed were applied to Neepawa. Similar increases occurred with the Cypress cultivar. The relationship of the differential response of subcrown internode growth to imazalil and the control of common root rot is discussed.