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Ecology and Epidemiology

Temperature and Moisture Requirements for Development of Anthracnose on Northern Jointvetch. D. O. TeBeest, Research Associate, Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701; G. E. Templeton(2), and R. J. Smith, Jr.(3). (2)Professor, Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701; (3)Research Agronomist, Agricultural Research Service, U.S. Department of Agriculture, Stuttgart, AR 72160. Phytopathology 68:389-393. Accepted for publication 5 August 1977. Copyright © 1978 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-68-389.

Colletotrichum gloeosporioides f. sp. aeschynomene is the causal agent of anthracnose on northern jointvetch. In controlled environments, disease developed rapidly between 20 and 32 C, but development was most rapid at 28 C. At 28 C, 16- to 18-day-old seedlings died within 8 days after inoculation. Incubation of inoculated seedlings in alternating day/ night temperature regimes of 32/24 C or 28/20 C reduced the rate of disease development compared with that at 28 C. Dew periods of at least 12 hr at 28 C were required to obtain infection of all seedlings. Incubation of seedlings at 24 or 32 C during the dew period increased the time required for disease development, and temperatures of 20 and 36 C during the dew period further reduced disease severity. Temperatures and dew periods in the rice field environment are similar to those required for rapid growth and development of the organism on northern jointvetch in the laboratory.