pnut pnut Peanut Science 0095-3679 0095-3679 American Peanut Research and Education Society 10.3146/i0095-3679-22-2-15 Articles Effects of Host Resistance on Germination of Cercospora arachidicola on Peanut Leaf Surfaces1 F. Waliyar , B. B. Shew *, R. Sidahmed , and M. K. Beute 2 Visiting Prof., Dept. of Plant Pathology; Res. Assoc, Dept. of Crop Science; Undergrad. Intern, Dept. of Plant Pathology; and Professor, Dept. of Plant Pathology, North Carolina State Univ., Box 7616, Raleigh, NC 27695–7616. [Dr. Waliyar is Prin. Scientist (Pathology), International Crops Research Institute of the Semi-Arid Tropics (ICRISAT) Western and Central Africa Region, Bamako, Mali.]

1ICRISAT Jour. Article No. 1755. This research was partially funded by the National Peanut Foundation and USAID Peanut CRSP grant DAN-40480G-SS-2065–00. Recommendations do not represent an official position or policy of USAID. Mention of a trade name or proprietary product does not constitute a guaranty or warranty of the product named and does not imply approval to the exclusion of other products that may be available.

 *Corresponding author. 7 1995 22 2 154 157 9 10 1995 Copyright © 1995 American Peanut Research and Education Society 1995 American Peanut Research and Education Society Abstract

Conidial germination by a North Carolina field-isolate of Cercospora arachidicola Hori was studied on leaf surfaces of two highly resistant and two susceptible peanut (Arachis hypogaea L.) genotypes under 5 day/night temperature regimes. Conidia germinated at all temperature regimes, but a greater percentage germinated at the coolest temperature regimes of 26 C day/20 C night and constant 24 C than in warmer temperature regimes. Percentage germination differed significantly with respect to time and genotype in each temperature regime. Fewer conidia germinated on resistant compared to susceptible genotypes, with lowest germination on the resistant genotype 91 PA 150 (a Virginia type derived from a cross of A. hypogaea and A. cardenasii Krapov. and W. C. Gregory). Conidia germinated more quickly and more conidia germinated overall on the susceptible NC 7 than on the other genotypes tested.

 Key Words Arachis spp; , groundnut; , early leaf spot