NEWS ARTICLE FOR MAY 19, 2008:
The rain event from last week really played havoc on vegetables. I have had numerous conversations with people who lost their entire garden to hail, wind or water. I saw some tomatoes up north of Holden that did not have a leaf on them and the hail had pulverized the green fruit.
I would expect to see more incidence of disease following those rains. Early blight shows up on the bottom tomato leaves after you have a splashing rain. The fungal spores bounce off the ground and land on the leaves. The fungus will appear as a brown circular spot on the lowest leaves and will move up the plant if left unchecked. The spots will look like a bullseye or target.
Use the fungicide chlorothalonil to control early blight. You can purchase under many retail names such as Ortho Daconil 2787 and Greenlight Daconil Vegetable Fungicide . Spray at 5-10 day intervals to protect your foliage and production.
Another problem I have seen since the last 2 rains is buckeye rot on the tomato fruit. It is also a fungus caused by splashing rain. It will make the tomato look like it is gray and water soaked. Once the disease gets very far along the tomato will turn to mush in your hand when you try to pick it. Buckeye rot is cause by a fungus that is a water lover. Controls for buckeye are largely cultural practices to reduce water build up and improve drainage. Use mulches to prevent splashing. Commercial growers can use Quadris and Ridomil fungicides.
I have also had several reports of bacterial wilt in tomatoes. This is a particularly devastating disease because it attacks the plant after it loads up with tomatoes and the temperatures start to get hot. The bacterial is in the soil and enters the vascular system of the plant. It literally clogs the “arteries” of the tomato until it can no longer uptake water and just wilts and dies over night. The typical complaint is that the tomatoes looked fine yesterday but today it looks like someone poured boiling hot water over them.
Another really bad part of bacterial wilt is there is no cure and the bacterial remains in the soil indefinitely. It also can affect peppers and eggplants but no other vegetable crops. It you have bacterial wilt move your tomatoes to the other side of the garden and plant early in the spring. Be sure not to move any soil from the infected over to any new ground as you can bring the problem with you. Clean your garden tools and tiller with chlorox before preparing a new area if you have bacterial wilt.
You might also try a new variety of tomatoes that shows resistance to bacterial wilt, BHN 669.
For more information on these or related topics contact Kenny at 686-3020.