Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 4/14/1999
Publication Date: N/A
Technical Abstract: Rhizopycnis vagum was isolated from the roots of 13-32% of 8-week-old cantaloupe ('Magnum 45', honeydew ('Honey Brew' and 'Morning Ice'), and watermelon ('Jubilee II') plants from a field with a history of vine decline disease of unknown etiology. The frequency of this fungus from subsequent biweekly isolations was similar through plant maturity. R. vagum has also been isolated from roots of melon plants exhibiting vine decline symptoms in Costa Rica, Guatemala, and Honduras. 'Jubilee' watermelon and 'Caravelle' cantaloupe plants inoculated with 1,600, 3,200, and 6,400 CFU s/g of soil had a significant reduction (p equal to or less than 0.05) in vine length and vine dry weight over untreated controls. Inoculated 'Jubilee' watermelon plants also had significantly higher root disease ratings and lower root dry weights as compared to other treatments. These data indicate that R. vagum is pathogenic on melon; thus, may be involved in the vine decline disease complex in Texas and other melon production areas.