Submitted to: Sociedad Espanola de Fitopatologia
Publication Type: Abstract Only
Publication Acceptance Date: 7/11/1996
Publication Date: N/A
Technical Abstract: Vine decline (collapse or sudden wilt) is a term used to describe a group of diseases, incited by several different microorganisms, that results in the death of melon vines as the fruit approach maturity. Fusarium wilt (Fusarium oxysporum) was for many years the predominant vine decline of both watermelon and cantaloupe in the southwestern U. S. Verticillium wilt t(Verticillium dahliae) of cantaloupe can cause significant losses in production areas especially during periods of cool weather. Gummy stem blight (Didymella bryoniae) is typically more important during periods of cool-wet weather. Charcoal rot (Macrophomina phaseolina) can be an important disease of cantaloupe in warmer production areas of the southwest. Purple stem (Diaporthe melonis) and Botryodiplodia decline (Botryodiplodia theobromae) occur infrequently and rarely cause significant losses. More recently, Monosporascus root rot/vine decline (Monosporascus cannonballus) has become the major vine decline of cantaloupe in the semi- arid and hot areas of Texas, Arizona, and California. The honey dew type melons do exhibit a high level of tolerance. Acremonium collapse (Acremonium cucurbitacearum) appears to be the limiting factor to melon production from the upper San Joaquin Valley to the Sacramento Valley in California. Some fields in the Rio Grande Valley of Texas have severe vine decline that cannot be attributed to M. cannonballus. In those fields, A. cucurbitacearum appears to be involved in the disease complex along with a Stagnospora-like fungus. Yellow vine (possible bacterialike organism) of watermelon and cantaloupe is a new and destructive disease in central Texas and Oklahoma. Symptoms are similar to other vine declines except that there is a prominent honey-brown discoloration of the phloem.