pnut pnut Peanut Science 0095-3679 0095-3679 American Peanut Research and Education Society 10.3146/i0095-3679-6-2-3 Articles Sclerotinia Blight of Peanuts in Oklahoma and Occurrence of the Sexual Stage of the Pathogen1 D. F. Wadsworth 2 Professor, Department of Plant Pathology, Oklahoma State University, Stillwater, OK 74074

1Journal Article No. 3516 of the Oklahoma Agricultural Experiment Station, Oklahoma State University, Stillwater, OK 74074.

 7 1979 6 2 77 79 27 6 1979 American Peanut Research and Education Society 1979 American Peanut Research and Education Society Abstract

Sclerotinia blight of peanuts was discovered in Oklahoma in 1972. The disease is caused by Sclerotinia sclerotiorum (Lib.) de Bary varieties “Minor” and “Major” Purdy (Whetzelinia sclerotiorum (Lib.) Korf & Dumont). S. sclerotiorum “Minor” is more prevalent. Sclerotinia blight has been found in seven of the 23 major peanut-producing counties in Oklahoma since its discovery and it is regarded as a major peanut disease. Both fungal varieties overwintered in the field as sclerotia and produced apothecia and ascopores from late April to early June. Peanut plants exposed to natural ascospore discharges in the field became infected with both varieties of the fungus.

 Key Words Arachis hypogaea; , Sclerotinia sclerotiorum “Minor” Sclerotinia sclerotiorum “Major”; , apothecial stage; , Whetzelinia sclerotiorum.