Wet weather raises concern for late blight for Vermont crops

In light of the recent heavy rains and continued cool, overcast weather, gardeners and commercial growers are reminded of the threat to tomatoes, potatoes, and other solanaceous vegetables from late blight. Reminiscent of 2009, the last few days have been characterized by cool temperatures and periods of rain and drizzle, conditions suitable for the development of the disease.
The Agency of Agriculture is alerting home gardeners and commercial growers of the potential of late blight this growing season. Late blight is a plant disease that spreads rapidly from plant to plant in wet, cool weather that causes tomato and potato plants, primarily, to wilt and die.
‘The exceptionally cool, damp spring we are experiencing throughout Vermont and New England this year heightens our concern for late blight,’ said Tim Schmalz Plant Pathologist. ‘We saw the devastation it can do to a tomato crop in 2009, and we have already received reports of early late blight detection in neighboring states. We want to remind our growers of this possible plant disease and alert them of the precautions they can take and how we, as a regulatory agency, are working to protect our plants.’
Late blight typically attacks tomatoes and potatoes during August and September, but it has already been reported this spring in Connecticut, Maine, and Wisconsin, and will probably become more widespread if cool, damp conditions persist. Growers of tomatoes, potatoes, peppers, petunias, and other susceptible plants are reminded to keep an eye on their plants for the appearance of irregular, bruised or ‘water-soaked’ appearing lesions on the leaves, white fuzzy or moldy growth at the margins of those lesions, and rapid browning and dieback of the affected plants.
Late blight control in home gardens and smaller greenhouses is best accomplished through prevention: remove and dispose symptomatic material immediately, apply preventative fungicides according to labeled rates, and when possible, cultivate late blight-resistant plants. Detailed information on registered fungicides, sanitary procedures, photographs of late blight, and more is available from the Agency of Agriculture, Plant Industry Section website:
http://www.vermontagriculture.com/ARMES/plantindustry/plantPathology/ind...,
or from the University of Vermont, Master Gardener Program:
http://www.uvm.edu/mastergardener/?Page=help/BlightInfo.htm.