Author
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Corsini, Dennis |
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Submitted to: Potato Conference and Trade Fair Proceedings
Publication Type: Proceedings Publication Acceptance Date: 2/12/1997 Publication Date: N/A Citation: N/A Interpretive Summary: This talk was presented to attendees at the 1996 Oregon State University Potato Conference. The movement of the late blight pathogen, Phytophthora infestans, from an obscure region of Mexico to Europe and North America is discussed. Programs to combat late blight began in the 1850s following the Irish Potato Famine, which was caused by the disease. Research continued into the mid twentieth century, with particular emphasis on developing resistant varieties. The ability of the fungus to overcome single gene resistance and the advent of effective fungicides led to reduced research on late blight until the mid 1980s, when new strains from Mexico moved into the major potato production areas of the world. Now a renewed effort is being made by research organizations throughout North America to develop varieties with durable resistance and to discover more effective fungicides and biological controls. Technical Abstract: Late blight caused by Phytophthera infestans is the most serious disease of potatoes. Selection of resistant cultivars began in the mid 19th century and is continuing today. New strains of the fungus have been able to overcome the resistance in older varieties developed in Europe and North America. New sources of general resistance are being evaluated in an attempt to develop varieties with durable resistance. The pathogen has also become insensitive to metalaxyl, the most effective fungicide used against it. Major agricultural chemical companies are evaluating a number of new compounds for effectiveness in controlling this disease. To date none has been found to be as effective as metalaxyl. |
