For 100 years bacterial spot has been causing huge losses for tomato growers worldwide. For 100 years products containing copper have held the key to controlling this devastating tomato disease. As tomato growers enter their second century of dealing with bacterial spot, the question has become whether copper applications lessen the severity of bacterial spot-or perhaps even make the disease worse. This article will discuss bacterial spot of tomato, why copper products have become less useful in the control of this important disease and finish with options for managing bacterial spot of tomato with and without copper. The first symptoms of bacterial spot one is likely to observe are small, less than 1/8 inch dark lesions on tomato leaves. The lesions may appear watersoaked, especially in the morning and are often surrounded by yellow (chlorotic) tissue. These lesions, whether found on leaves or stems, may coalesce to cause the loss[Read More…]
2 articles tagged "Fungicide".
Over the past few weeks, I have observed several watermelon fields with relatively large areas of wilted plants.There can be several reasons for such symptoms.In the article below, I will discuss late season Fusarium wilt of watermelon.In a separate article, I will discuss mature watermelon vine decline.In a separate article/blog I discussed root knot nematode.All of these diseases can cause wilt and decline of relatively large areas of cucurbits. Fusarium wilt of watermelon is often observed when the vines are just starting to touch each other within a row. Sometimes, however, Fusarium wilt of watermelon does not show up until later in the season when the plants are near maturity. Fusarium wilt at this point in the season may cause a few vines to wilt (Figure 1). The distribution of affected plants is due to the distribution of the Fusarium fungus in the soil. Often well drained areas of the[Read More…]
