Tips to help diagnose and correct tomato problems


By Robert Bourne - Guest columnist



Recent rains and the high humidity have set tomato plants up for lots of potential problems. Below is a listing of the more common tomato problems you may encounter and ways to correct them.

Early Blight

Symptoms: At first, the leaves have a few oval brownish areas in scattered locations. In a short time, infected leaves turn yellow. Leaves anywhere on the canopy can be affected, but symptoms show up on the lower limbs first.

Control: Weekly applications of products that contain Chorothalonil, Mancozeb, or copper sulfate.

Septoria Leaf Spot

Symptoms: Leaves start out with many small, circular gray to black spots about the size of a No. 2 pencil lead. The leaf quickly turns yellow, then brown, and drops from the plant. Leaves on the lower portion of the plant are most affected.

Control: Weekly applications of products that contain Chorothalonil, Mancozeb, or copper sulfate.

Blossom-end Rot

Symptoms: A single large black spot forms on the blossom-end of the tomato fruit.

Control: Before planting, add organic matter to the soil. After planting, mulch tomatoes with grass clippings or wheat straw. Water every 3 days, instead of weekly waterings. Soil test and add lime if needed.

Aphids

Symptoms: Tomato leaves may look pale and unthrifty, and have small clear specks of honeydew, which is secreted by the aphids as they feed on the plant sap. Aphids can quickly build up large numbers and will be visible on close inspection of the leaves and blossoms. They are pear-shaped, a little larger than pinhead size, and range in color from light green to tan to brownish gray.

Control

Spray as needed with insecticidal soap or a product that contains one of the active ingredients listed: Acetamiprid, Cyfluthrin, Esfenvalerate, Imidacloprid, Lambda-cyhalothrin, or Permethrin. Be sure to get thorough coverage with the spray, on both the top and underside of the leaf canopy.

Spider Mites

Symptoms: The first symptom is the loss of green color near leaf veins and petiole end of the leaf blade. The color change goes from green to creme or yellow and has a stippled appearance. When leaves are shaken over a white piece of paper, the dust-like particles move. Leaves at the bottom of the plant are the first ones attacked by spider mites.

Control: 3-4 applications of Insecticidal soap 3 days apart or Malathion

Tomato Fruitworm:

Symptoms: This green caterpillar is hard to find on the leaves. It enters the fruit and feeds on the inside of green tomatoes. Look for holes the size of a No. 2 pencil in green fruit. As fruit that is damaged ripens, fruit rot sets in, so it is best to remove fruit with holes as soon as you see them.

Control: Weekly applications of a product that contains one of the active ingredients listed: Acetamiprid, Cyfluthrin, Esfenvalerate, Imidacloprid, Lambda-cyhalothrin, or Permethrin every 10-14 days.

Tomato Pinworm

Symptoms: The tomato pinworm is a small caterpillar that enters the fruit at the stem end under the calyx. Look for brown frass (sawdust-like material) between the calyx and the fruit.

Control: Weekly applications of a product that contains one of the active ingredients listed: Acetamiprid, Cyfluthrin, Esfenvalerate, Imidacloprid, Lambda-cyhalothrin, or Permethrin every 10-14 days.

Nematodes

Symptoms: Plants grow slowly and are stunted producing little fruit. When plants are removed from the soil, the roots have a knobby appearance.

Control: Rotate tomatoes to new garden areas yearly. Do not plant tomatoes where tomatoes, peppers, potatoes or okra have been planted for at least 3 years. Plant winter cover crops of wheat or annual rye. For faster control, solarize the affected soil area by spreading out a soaker hose and covering the entire area with a clear plastic tarp. Keep soil under the plastic moist and keep covered for 6-8 weeks during June, July or August.

If you have any questions, or would like further information on this or other related management topics, visit us on the west end of the Clay Jones Community Building at 1901 S. 9th Avenue in Durant, or call (580) 924-5312.

The Oklahoma Cooperative Extension Service offers its programs to all eligible persons regardless of race, color, national origin, religion, sex, age, disability, or status as a veteran, and is an equal opportunity employer.

Robert Bourne is a Bryan County Extension Educator.

http://www.durantdemocrat.com/wp-content/uploads/2017/05/web1_Robert-Bourne.jpg

By Robert Bourne

Guest columnist

comments powered by Disqus