Apple replant disease occurs worldwide and was previously controlled by methyl bromide soil fumigation. We continue to evaluate non-chemical methods for controlling this serious disease problem, and studying the microbial bases for its causation and control. Our recent work has shown that several new rootstocks developed at Cornell have substantial resistance to this soil-borne disease, and may eliminate the need for soil fumigation.
It`s no surprise that severely diseased grapes make poor wine. However, we found that even trace levels of powdery mildew set in motion a sequence of events that results in severely downgraded and wine that could not be sold. The damage is not due to the powdery mildew itself, but to how it shifts the naturally occurring (and normally beneficial) microbial community on grape berries towards one that produces foul flavors and odors during winemaking.