VIEW ARTICLE

Disease Control and Pest Management

Tricyclazole: A New Systemic Fungicide for Control of Piricularia oryzae on Rice. J. D. Froyd, Research Scientist, Lilly Research Laboratories, Division of Eli Lilly and Company, Greenfield, Indiana 46140; C. J. Paget(2), L. R. Guse(3), B. A. Dreikorn(4), and J. L. Pafford(5). (2)(3)(4)Research Associate, Coordinator of Plant Science Research, and Research Scientist, Lilly Research Laboratories, Division of Eli Lilly and Company, Greenfield, Indiana 46140; (5)Plant Science Representative, 702 Gerald Drive, Lafayette, Louisiana 70501. Phytopathology 66:1135-1139. Accepted for publication 5 March 1976. Copyright © 1976 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-66-1135.

Tricyclazole [5-methyl-1,2,4-triazolo(3,4-b) benzothiazole, code number EL-291] is a unique new fungicide for control of Piricularia oryzae on rice. In vivo activity was 25 to 35 times greater than in vitro activity. Tricyclazole was systemic in rice according to foliar disease control achieved with root, seed, and soil applications and residue analyses. Field studies indicated that effective, long-term control of P. oryzae was obtained from foliar spray, seed coat treatment, soil drench in the transplant flat, and transplant bare-root soak applications. The effectiveness of tricyclazole by different methods of application offers new opportunities for disease control in seeded and transplanted rice.