Disease Note

Viruses Infecting Cucurbit Crops in Louisiana. F. F. Fernandes, Department of Plant Pathology and Crop Physiology, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803. R. A. Valverde, and L. L. Black. Department of Plant Pathology and Crop Physiology, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803. Plant Dis. 75:431. Accepted for publication 28 December 1990. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-0431B.

A survey for viruses infecting cantaloupe (Cucumis melo L.), cucumber (C. sativus L.), squash (Cucurbita pepo L.), and watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) was conducted in southeastern Louisiana during spring seasons of 1988 and 1989. A total of 340 samples were collected from plants showing virus disease symptoms. Enzyme-linked immunosorbent assay (ELISA) (antisera provided by H. A. Scott, University of Arkansas) and indicator host plant reactions were the diagnostic tests used. Zucchini yellow mosaic virus (ZYMV), the watermelon strain of papaya ringspot virus (PRSV-W), watermelon mosaic virus 2 (WMV-2), cucumber mosaic virus (CMV), and tobacco ringspot virus (TRSV) were detected. All five viruses were found throughout the region infecting all four cucurbits in both years. The average frequency of virus occurrence during the 2 yr was 50% for WMV-2, 45% for PRSV-W, 43% for CMV, 27% for ZYMV, and 21% for TRSV. Mixed infections were frequently detected. This is the first report of these viruses infecting cucurbits in Louisiana.