Answer: It sounds like your plants may have been affected by early blight (alternaria), a fungal infection. To reduce its spread, avoid overhead watering especially in the evening, space plants with ample air space between them, and remove and destroy any infected plants as soon as the problem is seen. Do not work on the plants if they are wet from rain or dew. Also make sure to allow a minimum of three years before planting tomatoes (or potatoes or eggplants) in that spot again and be scrupulous about fall garden clean up. The spores may also blow in on the wind, so you may consider a preventive spray program using a copper based spray or one of the soap products such as Soapshield. Your county extension (765-7878) should be able to suggest suitable sprays and recommended timing for their application in your area.
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