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Vegetables
Volume 58 Number 10 Date 07/11/2013 LATE BLIGHT - Three separate cases of late blight have been confirmed since June 28: two on commercial potato in Adams and Juneau counties and one on home garden tomato in Sauk County. Based on recent rain events and potential for spore dispersal, UW-Extension Plant Pathologist, Dr. Amanda Gevens is recommending preventative fungicide treatment of susceptible tomato and potato crops on a shortened 5- to 7-day spray interval. Scouting efforts should also be intensified, concentrating on field corners and areas sheltered by trees, where late blight symptoms first appear. Registered fungicides for potato late blight in Wisconsin are listed at the UW-Madison Vegetable Pathology website. CORN EARWORM - The early migration of moths continued for the sixth week at the Green Lake, Janesville and Ripon monitoring sites, while the first moths were registered near Wausau. Counts at Wausau and Janesville were low at 3 and 11 moths per trap, respectively, while the Ripon and Green Lake traps registered 29 and 105 moths from July 4-10. Larvae resulting from the flight have been found in corn in Dodge, Eau Claire, Green, Iowa and Sauk counties in the last two weeks although infestations are probably more widespread than indicated by our surveys. Cornfields should be checked regularly for this pest and treatment considered if 50% or more of the whorls are infested. STRIPED CUCUMBER BEETLE - Home gardeners in the southwest and west-central areas are reporting minor damage to cucurbits. Treatment may be justified for infestations of 4-5 beetles per 50 plants. SQUASH VINE BORER - The early-stage larvae of this insect are excavating the stems and runner vines, causing squash plants to wilt. Closer examination of the vines should reveal entrance holes from which their sawdust-like frass is expelled. Varieties most susceptible to squash vine borer damage are 'Blue Hubbard', 'Boston Marrow' and 'Golden Delicious', while 'Butternut', 'Dickenson pumpkin' and 'Green Striped Cushaw' have shown some resistance. -- Krista Hamilton, DATCP Entomologist |
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