First Report of Bell Pepper (Capsicum annuum) as a Host of Sclerotinia minor in California

In 1997, commercially grown bell pepper in the Salinas Valley (Monterey County), California, developed a previously undescribed disease. Plant foliage became pale green and wilted. Crowns developed brown lesions that girdled the plants, resulting in plant death. White mycelia and small (2 to 3 mm), black, irregularly shaped sclerotia were observed on the outside of plant crowns and in the centers of stem cavities. Isolations consistently resulted in the recovery of Sclerotinia minor. Pathogenicity was tested by inoculating 2-month-old bell pepper plants (cv. California Wonder) with sclerotia from three pepper and three lettuce (Lactuca sativa) isolates of S. minor (seven plants per isolate). Six to 10 sclerotia were placed 1 cm below the soil line and adjacent to the plant crowns. After 8 days, plants inoculated with pepper and lettuce isolates developed symptoms similar to those found in commercial fields, and S. minor was recovered from all peppers. The uninoculated control plants developed no symptoms. This is the first report of bell pepper as a host of S. minor.