Tomato plant

Healthy tomato plant. Photo by the University of Minnesota Extension. 

This year the weather has been quite abnormal. We started out with a very cool spring, after that the weather quickly shifted to hot, windy, and stormy. We are seeing quite a bit of problems with tomatoes lately and they all look similar but could be due to a few different problems.

Many people are seeing tomato plants with curling leaves. Most often these curled leaves are at the top of their plants and it is not usually all the plants that a person planted in their garden that are having problems. Sometimes it is just a couple of plants out of 10-12.

Environmental damage

The stress from the environment can be very harmful to our plants. When the weather quickly shifted to summer this year, it caused wilting from heat and drought stress. Sometimes that environmental stress can cause the leaves of tomato plants to curl upward. Watering can sometimes help this issue, but not always. The plants may need to get over the impacts on their own. With environmental issues, the plant will eventually grow out of the damage.

Another issue caused by the environment is called physiological leaf curl that can develop on tomato plants. This is a physiological issue, meaning it is a growth response in the plant. This response is caused by changes in the environment, usually when weather shifts from spring to summer. Typically, the plant will recover on its own. Correct irrigation can help speed up this process.

Herbicide injury

Herbicide injury is something that we often see in our plants. Tomatoes are especially sensitive to drift from 2,4-D and Dicamba products. With herbicide drift, curling, cupping and vein distortion of leaves.

The plant will likely grow new leaves that are not affected and look fine. However, it is not advised to eat fruits or vegetables from plants that were hit by herbicide drift, due to the variables regarding the herbicide, there is no way to know when or if they will be safe for consumption.

This year, since we were having such a chilly spring, we were able to spray herbicides later in the season. Then, when the temperatures shifted so quickly and these products were still being used, we had a lot more volatilization of the products making them move to our plants.

Virus

There is also a virus known as Beet Curly Top that can also be found in tomatoes. The experts are suggesting that this could be part of the problem as well. The symptoms from this virus are very similar to herbicide injury. As with all virus diseases, there is no cure for the plant. It is best to pull the infected plants as soon as the virus is noticed and destroy them to reduce the chance for spread of the virus.

So, whether your plants are facing herbicide injury or a virus, the best option is to remove the plants. This will reduce the chances of all your plants getting the disease and be safest for your household. If it is an environmental issue, the plants will grow out of it. If you are unsure of the cause, it is best to remove the plants. Be sure to keep them watered as necessary through the summer to help reduce the problems.

If you have questions, contact Nicole Stoner at 402-223-1384, nstoner2@unl.edu, visit the Gage County Extension website at www.gage.unl.edu, or like her Facebook page at http://www.facebook.com/NicoleStonerHorticulture and follow on Twitter @Nikki_Stoner.