Symptoms of southern corn leaf blight progress into long, oblong, tan or grayish lesions. Southern corn leaf blight incited by Helminthosporium maydis Nisikado & Miyake evolved from a minor disease that causes an average annual loss of less than 1 percent, to one that caused more than the 12 percent average expected from all diseases of corn in the United States. Seedlings from infected kernels are often blighted. The typical symptoms are oval to slightly elongated lesions, ¼ inch to 1 inch long (Figure 1). Symptoms. Cochliobolus heterostrophus. Common Name. To view more on Southern Corn Leaf Blight … Southern corn leaf blight, caused by Race T of the fungus Bipolaris (Helminthosporium) maydis, forced US crop breeders to consider the detrimental effects of planting only one genotype of a crop.If the specific genotype used isn’t resistant to a particular invader, then the whole crop could be lost if the pathogen establishes itself in the environment. Southern corn leaf blight . In 1970 the losses to corn leaf blight approaches 710 million bushels. This fungal disease favors wet conditions and warm temperatures, as well as reduced tillage and continuous corn production. Cochliobolus heterostrophus; this is the name for the sexual stage; the asexual stage is known as Bipolaris maydis (previously it was Drechslera maydis and before that Helminthosporium maydis).There are different races. Of these diseases, Goss’s wilt can cause significant yield loss on susceptible hybrids in ND. It seems --Herbert H. Kramer Director, Purdue Agricultural Experiment Station 1. The invasion of the Southern Corn Leaf Blight into Indiana during recent weeks has caused great concern. 1 Consequently, SCLB typically is a common disease of fall crops of sweet corn in Georgia and Florida. Here follows background information that may help you assess the situation. Southern corn leaf blight (SCLB), caused by the fungus Cochliobolus heterostrophus (also known as Bipolaris maydis), has been observed at several locations in the Lower Rio Grande Valley in the fall corn crop this past month. Southern corn leaf blight is caused by the fungus Bipolaris maydis, which primarily follows an asexual disease cycle. Ear infections result in a gray-black lesion on the husk that extends into the kernels, appearing as a black felt-like mold. Pathology This disease is caused by the fungus pathogen, Helminthosporium maydis. As it was, the Southern Corn Leaf Blight devastated 15 percent of America's 1970 corn crop, reducing the average national corn yield from 83.9 to 71.7 bushels per acre, costing farmers about $1 billion in losses. Compared to NCLB, it develops at warmer temperatures, between 68 to 90o F, and under damp conditions. Scientifically, southern corn leaf blight disease represents a fascinating system for the study of fungal toxin action and, in addition, provides us with a unique tool for the Variation in lesion size and shape may occur between inbreds and hybrids with different genetic backgrounds. Scientific Name. Southern corn leaf blight lesions on leaves are seen at the mid-whorl stage through maturity. The other leaf disease that has been reported to a lesser extent is northern corn leaf blight. Some southern states lost more than 50 percent of their corn crop. SOUTHERN CORN LEAF BLIGHT (SCLB) This disease is caused by the fungus Bipolaris maydis. Lesions on maize leaves, caused by race O, are elongated between the veins, tan in colour, 2-6 x 3-22 mm long, with limited parallel margins and buff-to-brown borders. Southern corn leaf blight. Southern leaf blight, southern corn leaf blight, southern leaf spot, maydis leaf blight. 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