|
|
Tomatoes got you down?Oklahoma It's the time of year to start harvesting our favorite summer crop. Unfortunately tomatoes can have a lot of problems around picking time. Some of these are due to unfavorable environments, lack of essential nutrients, and insects. Some common issues include blossom drop, blossom-end rot, leaf rolling, herbicide injury, and insect feeding. Blossom drop is a loss of blooms and failure to set fruit. This could be due to excess nitrogen fertilizer or increased heat and wind. Some more heat tolerant varieties are available, along with "bloom-set" sprays. However, the effectiveness of blossom sprays can be inconsistent. Blossom end rot causes a brownish black decaying region at the blossom end, usually when the tomato is half grown. Roma tomatoes are very susceptible to blossom-end rot. The rot is usually caused by a calcium deficiency or the inability to uptake calcium, and/or uneven watering. To prevent blossom end rot, the use of nitrate, not ammonium forms of nitrogen fertilizers can make calcium more available to the plant. In addition, watering deeply and evenly can help reduce the occurrence of blossom end rot. Leaf rolling is an upward curling of the leaves, which become tough and leathery. Usually this is just a cosmetic issue and the plant still blooms and sets fruit. Leaf rolling can also be a sign of disease, such as curly top virus. Leaf roll does occur more on plants that are staked and pruned, but can also be more prevalent on certain varieties. A well-drained site can be helpful to protect against leaf roll. Another problem with plants can be herbicide damage from surrounding areas or fields. Typically this is caused by 2,4-D or dicamba products. The young leaves will be very distorted: narrow, unfurled, curled, and almost unrecognizable. This will be rather uniform on the plant, which can distinguish herbicide damage from another disease symptom. Holes in the leaves are usually due to a type of larvae feeding on the leaf. Butterfly and moth larvae can be deterred with the use of Bt or hand picked off the plant in low numbers. Bt (Bacillus thuringiensis) is a bacteria that is ingested by the insect and subsequently kills it. Therefore, it is considered an organic control. Stink bugs can also be a problem in tomato plants. Stink bugs are true to their name and have a foul odor when disturbed. They can be green or brown and have a triangular shield shape on their back. These are true "bugs" that can feed on the plant and also leave white areas just under the skin of the fruit. Stink bugs can be controlled by use of products containing carbaryl or other approved insecticides. Aphids are very small, long-legged, plant sap feeding insects. They can usually be knocked off the plant with a firm stream of water. In some cases, water sprays are enough to keep them off the plant. Also, aphids are ladybugs favorite snack and they will usually come in and reduce aphid populations. Be on the lookout for small, black and yellow or red "alligators," which are ladybug larvae. They're a good thing. Access our Fact Sheets online at: osufacts.okstate.edu and enter the keyword in the search box. For more information, call your local Extension office or the Cleveland County OSU Extension Office at 405-321-4774 or come by our office at 601 E. Robinson St. in Norman. 9/29/08 Date: 9/22/08
Copyright/Privacy
Copyright 1995-2011. High Plains Publishers, Inc. All rights reserved. Any republishing of these pages, including electronic reproduction of the editorial archives or classified advertising, is strictly prohibited. If you have questions or comments you can reach us at High Plains Journal 1500 E. Wyatt Earp Blvd., P.O. Box 760, Dodge City, KS 67801 or call 1-800-452-7171. Email: webmaster@hpj.com |
|
