Leaf Curl. Curled or rolled leaves is a physiological disorder of tomatoes that is often associated with hot dry weather or wind, however it can also occur in response to other stresses like high moisture and nitrogen, fast growth, heavy production, pruning and root damage. Many references out there to checkout. While its exact cause may be unknown, it’s believed to be a sort of self-defense mechanism. Although the leaf roll symptoms are similar to those caused by certain viruses (curly top and tomato yellow leaf curl, for example), the symptoms noted in the PNW in 2009 were likely the result of a disorder on tomatoes called ‘physiological leaf roll.’ Physiological leaf roll starts with upward cupping at the leaf margins followed by inward But if your plants are green and no other symptoms appear, it’s probably plain old “tomato leaf roll”. Removal and destruction of plants is recommended. Some of these invite more serious consequences than others. Lack of other symptoms (yellowing, parallel veination, lack of vigor, stunting, etc.) I'm also very careful with how often I water them. It is more prevalent in vining tomato plants than bush types. Physiological leaf roll Physiological leaf roll on some tomato cultivars is normal and not harmful. This is by far the most common form of leaf curl and is a growth response to environmental conditions. It can also be a temporary condition caused by weather conditions or by an inconsistent supply of moisture. The challenge (and honestly a bit of fun for me) is to trouble shoot and hopefully resolve the issue. The good news for tomato growers is that physiological leaf roll has no ill effects on the plant's growth or fruit production. Joey Williamson, ©2014 HGIC, Clemson Extension Leaf Roll: Leaf roll of tomatoes may be caused by high temperatures, prolonged periods of wet soil conditions, and drought. Another cause of tomato plant leaf curling, also known as leaf roll, is attributed to physiological conditions. Leaf Curl: I’m seeing one of my plants experiencing tomato plant leaf curl, also known as leaf roll. Leaf roll on tomatoes is not caused by disease and does not affect yield or fruit quality. I’ll summarize them a bit and you can follow the link for all the details. There is no treatment for virus-infected plants. Reasons Why Tomato Leaves Curl Physiological Leaf Roll Causes: Physiological leaf curl occurs when the tomato plant undergo vigorous top growth coupled with inadequate root growth. Many serious tomato diseases, including curly top, mosaic, fusarium and herbicide injury, begin with rolling leaves. The only cause I can think of is that it … A second virus, tomato mosaic virus, causes rolling of leaves, but other symptoms, including mottled-coloring of leaves, small leaflets and internal browning of infected fruit, distinguish it from physiological or herbicide-induced leaf roll. Tomato leaf curl or roll may be caused by a variety of reasons. During excessively cool, moist conditions, leaves may roll upward and become leathery in an effort to repel this excessive moisture. My tomato plants have developed leaf roll and I'm really worried that this is going to affect productivity. Tomato foliage exhibiting leaf roll – the upward curing of lower leaves during high temperatures and drought. A: Rolled tomato leaves can be caused by several things. I have checked the leaves, there are no purple veins and I don't use herbicides. These include viral infections, physiological factors, chemical injuries, environmental stresses, or a variety of these factors. Tomato leaf roll is not a disease in the normal sense, but a physiological reaction to stress.