The epidemic illustrates the vulnerability of our food crops to pests. Reserves of corn and other grains ease the impact on the economy and food supplies but there are important domestic and foreign effects of the loss. In 1970 the losses to corn leaf blight approaches 710 million bushels. 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. Research at Coastal REC and University of Georgia in 2021 showed the rootstock ‘Maxifort’ was resistant to southern blight and increased yields in infested fields.A dramatic shift in the genetics of host-parasite interaction and balance occurred in the U.S. Growers who are concerned about southern blight this year should read up on the disease before planting a susceptible crop in the same field again. Ideally, diseased plants should be removed before sclerotia form or when the sclerotia are still white (as in the photo above), so sclerotia do not fall off diseased stems and remain in the soil despite the work of removing the plants. Do not add diseased plants to compost piles, because the sclerotia (survival structures of the fungus) may survive composting. Growers and home gardeners should remove diseased plants from the field and burn them. Once disease appears, there are no organic options to manage it in the current crop.
0 Comments
Leave a Reply. |