Watch for Early Blight in Tomatoes

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Tomatoes are America’s favorite garden crop and although they taste great, they can be difficult to grow. They are susceptible to many diseases and insects, many of which they can withstand without major damage. But there are a few tomato issues that have to be addressed as soon as they are noticed.

Early blight is a fungal disease of tomatoes. The fungus is present in the soil at all times and when weather conditions get just right (cool, damp weather), they invade your tomato crop. Early blight symptoms consist of dark brown irregular spots on lower leaves and/or stems and fruit. These lesions get larger as the disease progresses and eventually they develop concentric black target rings around the lesion. Yellowing around the areas can eventually occur and the leaf finally dries up and dies. It is important to remember that this starts at the bottom of the plant.

Now that you know what early blight looks like, how do you prevent, control or cure it? There are no cures for early blight so prevention and control are the only alternatives. Prevention is the best, but planning ahead is necessary. Never plant in the same spot more than once every three years. Clean up all plant and fruit debris at the end of the season. Early blight can overwinter in dead foliage and fruits. Mulch around tomato plants at the time of planting. Use plastic, straw, newspaper or landscape fabric. Remember that this disease lives in the soil. When hard rains come, soil is splashed on to lower leaves and stems where it creeps up the plant. Mulching keeps soil away from the plant. Control can slow down the spread of early blight. Garden fungicides containing either mancozeb or chlorothalonil are available at local garden centers and hardware stores. The key to successful control is to apply when the disease is first noticed and to continue at seven-day intervals. These fungicides act as a protective spray on the unaffected leaves and stems but must be re-applied often.

Early blight control has numerous options and the gardener should choose which of these techniques best suits his garden routine. Examine plants often and don’t ignore the signs of developing problems. The early bird gets the tomatoes!

If you need additional information on early blight in the garden, you can give our office a call at 439-4460.

Written By

Photo of Donna Teasley, N.C. Cooperative ExtensionDonna TeasleyExtension Agent, Agriculture - Horticulture (828) 439-4460 Donna_Teasley@ncsu.eduBurke County, North Carolina
Posted on Jun 3, 2014
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