![]() ![]() If you plan to work with the plants you have, there are couple of fungicides that may have some suppressive characteristics and are registered for use on ornamentals. If you dig up the entire plant, turn the soil over to help sclerotia decompose more quickly. Also remove the top several inches of soil around the plant, again being careful not to spill any as you work. Remove all of the infected plant parts, placing them directly into a bag to remove them from the garden. How do we manage this disease on hosta? The fungus is spread by sclerotia or by mycelium growing from the sclerotia. Hosta is only one of many hosts of this fungus. The pathogen has invaded our state, probably from the south, and probably as sclerotia on transplants. Tiny tan, mustard seed-sized sclerotia (fungal survival structures) can be seen in this mycelium and on the soil as shown in the second image. This is often referred to as a fan of mycelium. The first image shows this mycelium on an infected hosta in Urbana this past week (photo courtesy of Travis Cleveland). The fungus, Sclerotium rolfsii, appears as a flat, white matt of mycelium on the petioles and surrounding soil. The entire leaf collapses above the site of infection. ![]() In a short time the upper leaves also wilt and close inspection shows a soft, brown rot of the base of petioles. Symptoms begin in hot, humid weather with wilting and discoloration of lower leaves. In fact, research at Iowa State University has shown that the pathogen can survive under mulched hostas, but the fungus is often killed when mulch covering is removed before winter. The popular practice of mulching plants, especially over the winter, has helped protect this fungus through otherwise killing low temperatures. For many years it was thought of as a southern disease because it was not known to survive typical Midwest winter (low) temperatures. Sclerotium blight, also known as Southern Blight, is caused by a fungus, Sclerotium rolfsii. It is truly amazing that a fungal pathogen can so totally take over a large, otherwise healthy, hosta, causing all of its leaves to collapse. I beg the pardon of the grower whose hosta was devastated by this disease. When you plant corn again, choose a variety resistant to southern corn leaf blight (SLB).This past week we had a beautiful case of hosta petiole blight. Meanwhile, you can grow other vegetable crops in the plot. Wait four years after growing corn in an area before planting corn in that same area again. The fungus overwinters in the debris left in the corn field, so clean up the corn stalks and leaves at the end of the season and till the soil thoroughly and often to help the roots and underground stems break down.Ĭrop rotation goes a long way toward helping to prevent the disease. There is no way to save a crop that has the southern leaf blight fungus, but there are a few things you can do to save future crops. Even so, the symptoms and treatments described for the control of southern corn leaf blight may be similar to other leaf blights. ![]() Leaf blights in northern and western climates are caused by different fungi. Southern corn leaf blight, caused by the fungus Bipolaris maydis, occurs around the world, but it does the most damage in warm, humid climates such as the southeastern U.S.
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