Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/29/2012
Publication Date: 9/1/2012
Citation: Nyczepir, A.P., Kluepfel, D.A., Waldrop, V., Wechter, W.P. 2012. Soil solarization and biological control for managing Mesocriconema xenoplax and Short Life in a newly established peach orchard. Plant Disease. 96:1309-1314. Interpretive Summary: Ring nematodes are widely distributed throughout the world with certain species considered to be economically important to the stone fruit industry. Probably the most studied ring nematode species on Prunus is Mesocriconema xenoplax. This ring nematode is the only plant-parasitic nematode that has been associated with the peach tree short life (PTSL) disease complex in the southeastern United States. Tree loss due to PTSL in South Carolina alone was estimated at over $5 million per year. New alternatives to chemical control (i.e., biological control & soil solarization) that are less hazardous to man and also more environmentally safe must be found to protect peach trees from this ring nematode. In the early 1990's, five bacteria strains of Pseudomonas spp. were isolated from a nematode-suppressive soil in South Carolina that were later shown to inhibit ring nematode multiplication under laboratory and greenhouse conditions. The efficacy of the Pseudomonas spp. cocktail on ring nematode population was then investigated in conjunction with and without soil solarization or wheat under peach orchard conditions from 2004-2011. Results indicate Pseudomonas spp. cocktail did not suppress the ring nematode population in this study. However, the treatment solar-wheat was as effective as methyl bromide fumigation in increasing tree survival from PTSL for at least six years after orchard establishment. These data provide useful insights into the potential use of soil solarization as a preplant alternative to chemical control of the ring nematode on PTSL sites in the Southeast.
Technical Abstract: The effects of soil solarization with and without Pseudomonas spp. cocktail or wheat rotation as alternatives to chemical control of Mesocriconema xenoplax were investigated from 2004-2011. Preplant solarization and methyl bromide fumigation establishment was initiated in 2004, in an orchard infested with M. xenoplax and a history of peach tree short life (PTSL). Plots consisted of nine treatments: i) nonsolarized soil-alone, ii) nonsolarized soil with bacteria (nonsolar-bacteria), iii) nonsolarized soil with wheat (nonsolar-wheat), iv) nonsolarized soil with bacteria and wheat (nonsolar-bacteria-wheat), v) solarized soil-alone, vi) solarized soil with bacteria cocktail (solar-bacteria), vii) solarized soil with wheat (solar-wheat), viii) solarized soil with bacteria and wheat (solar-bacteria-wheat), and preplant methyl bromide fumigation (MBr). Peach trees were planted into all plots in 2005. Nematode populations were suppressed 20 months longer after orchard establishment in solar-alone and solar-wheat plots than solar-bacteria and solar-bacteria-wheat. Pseudomonas spp. cocktail did not have a pronounced effect in suppressing M. xenoplax in this study. Fumigation effect on M. xenoplax population density collapsed 24 months after application. Solar-wheat treated soil was as effective as preplant methyl bromide fumigation in increasing tree survival from PTSL for at least six years after orchard establishment.