Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 4/5/2005
Publication Date: 6/1/2005
Citation: Roberts, P., Muchovej, R., Urs, R., Achor, D., Baker, C., Bruton, B., Adkins, S. 2005. Investigation into a mature watermelon vine decline and fruit rot. Phytopathology. 95:S89.
Technical Abstract: In spring and fall production seasons of 2003 and 2004 in Southwest and West Central Florida, severe plant losses occurred as the watermelon crops were approaching first harvest or soon thereafter. Leaves initially exhibited a slight yellowing and quickly turned scorched and brown, followed by wilting and rapid collapse of the entire vine. A uniform tan to light brown discoloration was present in the xylem in affected plants. Although there were no external symptoms, the fruit on the declining vines frequently had rinds with greasy and discolored (brown) internal symptoms and were non-marketable. Symptoms in fruit were generally restricted to the rind, although the mesocarp sometimes exhibited a water-soaked appearance without maceration. Disease progress was very rapid, reaching 80–100% within a week. Abiotic and biotic causes were investigated. In attempts to link cultural practices, growers were asked to provide information on all cultural practices performed at the farm. Several pathogenic fungi and bacteria were recovered from symptomatic crown, root, foliar, and fruit tissue. Test plants died after inoculation in assays for viruses or virus-like agents indicating that these may be a contributing cause. Field trials examining host susceptibility and other factors were initiated in fields that had plants previously affected by the disease.