Learn about controlling tomato blight disease including resistant varieties.
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We’ve all seen it happen. Your tomatoes are growing great with vigorous growth, flowers and even small fruits. Then it starts on the bottom leaves with some spots or browning. Slowly it spreads. Then more quickly to engulf the plant until by mid summer your prized tomatoes are nothing but stems with a few fruits. Welcome to the world of blight.
The main foliar diseases of tomatoes are early blight, late blight and septoria leaf spot. Although, they look a little different from each other, the results are the same. And they are more severe during cool, wet weather.
Luckily, now there are a number of resistant varieties. ‘Iron Lady’ is the latest from Cornell with resistance to all three fungal diseases. ‘Defiant’ is another red, medium-sized determinate variety. ‘Jasper’ and ‘Mountain Magic’ are red cherry tomatoes with good disease resistance. Even some heirlooms, such as ‘Matt’s Wild Cherry’ and ‘Lemon Drop’, have shown some resistance to these diseases.
So starting with resistant varieties is key, but what about your other favorite hybrids or heirlooms. Here’s what to do. Grow your own seedlings or buy disease free seedlings from local growers. Plant in well-drained soil in full sun on a raised bed covered with red or black plastic mulch. Space plants at least 2 to 3 feet apart for good air circulation and cage or trellis your plants to keep them off the ground. Bottom water to avoid wetting the leaves. Pick off any leaves that show signs of the disease. Spray with Serenade or copper fungicide to prevent the disease spread. With some diligence you can still enjoy some luscious tomatoes on this summer’s Caprese salad.
From The Vermont Garden Journal.