Troubleshooting tomato troubles

Published 10:46 pm Friday, June 16, 2017

We’ve had somewhat of an early spring this year. Many of our gardens have gotten off to a great start. If you’ve noticed that your tomato plants are growing well but you don’t have any flowers, this may be a fertilizer problem. Lush, vegetative growth is usually due to over fertilizing with water soluble liquid fertilizer. Many of these fertilizers are high in nitrogen which stimulates the vegetative growth at the expense of flowering. Bob Westerfield, UGA extension specialist, recommends halving the ratio that is recommended on the container.

Some problems such as leaf curl are caused by fluctuations in moisture condition. The tomato plant goes from very wet conditions to very dry conditions. Even out the moisture swings. Mulch the plants with pine straw, pine bark, compost, or newspapers to maintain an even soil moisture. Do not let the plant become water stressed but don’t over water. Tomatoes need 1.0 to 1.5 inches of water per week. Avoid hoeing that may dry out the soil near the plant as well. If necessary, hoe shallow. Be aware that black plastic mulch may cause overheating of the tomatoes as well. The point is not to cause extreme fluctuations in soil moisture that may cause Blossom End Rot.

Blossom End Rot looks like a small darkened or water soaked area around the blossom end of the fruit. Usually it becomes inedible plus it’s very unsightly. It’s caused by a lack of calcium in the fruit. You can have plenty of calcium in the soil and the correct pH and it will still happen. It happens more often when the pH and the calcium level are low. Calcium in the soil is dissolved and transported up through the plant.

Most of us tend to over fertilize tomatoes with nitrogen. This spurs rapid growth in the leaves and the vegetative part of the plant. When it gets hot and dry, water will be transported to the leaves first. This is where most of the calcium will end up instead of the fruit. Most of this water will be lost to transpiration as the plant strives to stay cool. Blossom end rot usually shows up in the first cluster of fruit. When fertilizing tomatoes, limit the nitrogen by using a 5 – 10 – 10 fertilizer ratio. Ratios such as a 10 – 10 – 10 or 13 – 13 – 13 may cause problems. The first number is the percent nitrogen in the fertilizer.

Using the spray on liquid calcium products usually don’t work because by the time the fruit is set, it’s very difficult to get the calcium through the skin of the tomato which is much thicker that the leaves. 90% of the calcium that the fruit requires should be there by the time the tomato is the size of your thumbnail. As the tomato matures, the bottom shrinks due to the lack of calcium. Now some of the calcium that you spray on may end up in the soil and absorbed by the roots and moved up to the new fruit sets. You can mix your own calcium chloride (95 percent Calcium Chloride) solutions at a rate of four level tablespoons per gallon of water.  Apply every seven to 10 days until you have made three or four applications. This will salvage your remaining crop.

Other preventive measures are to soil test. Then lime and fertilize to test recommendations. The pH needs to be between 6.0 and 6.5.  Mix the lime and fertilizer into the root zone prior to transplanting the tomatoes.

Wet weather also stimulates diseases. The best bet against diseases is to select resistant varieties but diseases can still be a problem. When examining plants for disease problems, the lower leaves will usually show symptoms first. Warm, wet weather is usually indicative of disease problems in tomatoes. Septoria Leaf Spot and Early Blight usually attack the lower leaves first and both may be present at the same time.

Septoria first appears as small, water-soaked spots that become circular spots about 1/8th inch in diameter. It progresses to grayish white centers. Tiny, black specks may appear at the center. These are the fruiting fungal bodies. Spores may be spread by splashing rain. The lower leaves turn yellow, whither and fall off.

Early Blight most obvious symptom is the premature loss of the lower leaves. Brown to black spots ¼ inch to ½ inch with dark edges appears on the lower leaves. The spots merge forming a “target” appearance. The fungus may also attack the stem end of the fruit causing concentric rings and black, velvety appearance. Pick off these contaminated leaves and hopefully this will curtail the spread of the fungus. Make sure you have plenty of airflow as well. This keeps the leaves dry and hinders the fungus growth.

These diseases are difficult to control. Rotating where you plant both tomatoes and peppers every three years will help to prevent a buildup of the funguses in the soil. Removing dead leaves and debris from the base of the plants will also help. Mulching beneath the plants as previously stated will also prevent contaminated soil holding the spores from splashing onto the plants during a rain. Rotating approved fungicides for tomatoes at the beginning of the growing season may help as well.

Producing a good crop of tomatoes is not always easy. If you run into any problems, try some of these solutions.

What’s going on in Extension?

Summer 4-H program sign up is now. Call Melanie Dabb at 706.302.8784 or email for more details.

Market on Main: Every Saturday at the Carmike parking lot from 8 a.m. to 10 a.m.; The freshest produce in Troup County.

June 19: Beekeepers Meeting, 7 p.m. at the Ag Center; Keith Fielder: Mite Control

June 20th: Troup County Cattleman’s, Philip Brown, NRCS: Grazing Management, Dinner is at 7 p.m., cost $6, call ahead and the program begins at 7:30 p.m. at the Ag Center.

If you have any questions or concerns, stop by or call the office.

Brian Maddy is the ANR Agent for Troup County Extension. The Troup County Extension office is located at 114 Church Street, LaGrange, GA. 30240 (706) 883-1675. Monday – Friday/8 a.m. to noon and from 1 p.m. to 5p.m.