Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu
Be on the lookout for buckeye rot caused by Phytophthora nicotianae. This is primarily a disease of processing tomatoes that are ground grown, not trellised. Large brown water soaked spots with concentric rings that resemble a buckeye are seen on the fruit. Once seen it’s too late for control. Ridomil or MetaStar needs to be applied to the soil surface under the vines 4-8 weeks before harvest.
