Eighteen acres of greenhouse tomatoes may not sound like big business compared to several million acres of traditional agronomic crops planted each year in Mississippi, but to the crop's 125 growers, it is.
Greenhouse tomatoes taste  as great as they look.		Fusarium crown and root rot  was a real killer disease when  resistant varieties were  not available.

IPM Training for New Growers Emphasized

IPM practices for greenhouse tomato production include early pest detection, biological controls, environmental management, and use of disease-resistant varieties.
    In promoting these practices, education has been essential, and the Mississippi program emphasizes training for new growers as well as providing all growers access to the most current IPM information available.
    Growing greenhouse tomatoes in Mississippi used to be more difficult than it is now. Disease-resistant varieties were not available in the past and IPM practices were largely nonexistent. As grower Wayne Smith said, "In the 1980s, my approach was to try and spray away insects and diseases with insecticides and fungicides. I'm lucky I'm still in business because I lost a few crops with my brand of pest management."
 

IPM Now Used Routinely

Smith is typical of most of Mississippi's greenhouse tomato growers, who now routinely rely on IPM to handle insect pests (whiteflies, leaf miners, pinworms, aphids, and thrips) as well as diseases such as Botryt is gray mold, Fusarium crown and root rot, Pythium root rot, and powdery mildew-all of which are capable of reducing fruit yield and quality.
    Growing consumer demand for greenhouse tomatoes produced with limited use of pesticides has also influenced increase use of IPM for this product.
    One of the key components of the IPM program is provided by a technician who visits greenhouses on a regular basis, training new growers on pest identification, scouting, record keeping, and other IPM techniques.
 

Early Detection Is Key

The key to successful IPM is to identify and manage the inevitable pest problems before they become widespread. Need for this approach really hit home in 1995, when scouting in several south Mississippi greenhouses revealed symptoms of late blight, a highly destructive fungus disease. That early detection saved an estimated $35,000 for one grower, who was able to implement management procedures before the disease wiped out his crop. The discovery probably also prevented pathogen spread to other nearby greenhouses.
    Growers are now turning to biological strategies as an alternative to insecticides. For example, a small predatory wasp, Encarsia sp., is used to control whiteflies, the number-one insect pest of greenhouse tomatoes. The wasps are released inside greenhouses at intervals during the season, and they destroy whiteflies as soon as they appear.
 

Environmental Changes Effective

Humidity in greenhouses creates an environment highly favorable to fungus diseases. Growers, however, have learned to use air circulation and other techniques to keep humidity levels below the point where Botrytis gray mold and other fungus diseases are likely to develop. Growers also now have more disease-resistant varieties available. Through selection of varieties resistant to the highly destructive diseases of Claclosporium leaf mold and Fusarium crown and root rot, they have been able to prevent problems.
    Continuous IPM program updates are available. Monthly articles are published in the Mississippi Vegetable Press, a newsletter distributed not only to Mississippi growers, but to growers in 16 other states. Additionally, Extension publication Greenhouse Tomatoes-Pest Management in Mississippi No. 1861 is annually revised and distributed to growers at the Mississippi Greenhouse Tomato Short Course. In 1998, growers from 14 states and two foreign countries attended this course.
 

More IPM Information on Web

Up-to-date information also will be available on the Web site of the Department of Entomology and Plant Pathology, which is currently under construction.
    IPM has had major positive impact on the greenhouse tomato industry in Mississippi. Growers who use IPM practices as part of their greenhouse tomato production program maintain a 30 percent yield advantage. That means an extra six to seven pounds of fruit per plant over the year a net benefit of slightly more than $11,500 per quarter acre.
 
 

This is about as good as it gets for a greenhouse tomato grower, but the crop has to be protected from diseases and injurious insects through an IPM program.	Botrytis gray mold is greenhouse tomato public enemy number one; however, this fungal disease responds to an IPM program, and severe fruit loss can be avoided.
Vine ripened and ready for harvest.	For more information contact:  Clarence Collison  Department of Entomology and Plant Pathology  Drawer Box 9775  Mississippi State, MS 39762  (601) 325-2086