Once tomatoes are over their initial transplant shock and begin to push out new growth, growers often breathe a sigh of relief. Most growers got their plants in later than they would have liked but finally, whether inside a tunnel or out in the field, the plants are really taking off.
Tunnel grown tomatoes get more attention from growers than field grown but it’s always a good idea to pay close attention to all your crops in an effort to catch problems early on. Here are a few leaf symptoms that may catch your eye this month. Remember you can call on any of us in the Eastern NY program to help you diagnose what’s going on.
Leaf Roll (photo A) has a dramatic look and comes on suddenly, causing quite a shock to many growers. Luckily it’s a physiological response to stress and the plants should grow out of it. It occurs most commonly the day after a heavy pruning in tunnels. If the soil is dry when you do the pruning, the stress will be even greater. Try to get into the habit of pruning a little bit every week, rather than one big pruning job less often. Sometimes it can’t be helped so make sure your plants have a good soaking and let them grow out of it.
Virus-like symptoms (photo B) are more subtle but very distinctive. Where leaf roll is usually a lengthwise curling of full-sized leaves, the various virus diseases cause cupping, oddly scalloped and cut, and odd color patterns on the leaves. This photo shows one example of what a virus can do to leaves, there are other variations but there is a similar oddity to them that makes them distinctively viral.
Magnesium deficiency (photo C) can be startling but this is not an issue. It starts on the lowest leaves and works up the plant very gradually. It first appears when the first fruit clusters begin sizing up and as long as basic nutrient needs are being met, it is not a concern. Tunnel grown tomatoes push out vigorous growth and can become deficient more quickly than field grown. A foliar sample will give you much more accurate information. Epsom salts and sul-po-mag are some sources of supplemental magnesium.


Leaf Roll (pdf; 442KB)