Control Plant Diseases in yard and garden
BP 8-1 February 1974

Tomato Disease Control in the Home Garden
W. R. Stevenson, D. H. Scott, P. C. Pecknold Extension Plant Pathologists

Tomatoes are one of the most important vegetable crops in Indiana, the vast majority being grown for processing or fresh market, in addition, most home gardens have a few tomato plants.

Tomatoes, like all plants, are susceptible to diseases that limit or reduce yield and reduce the quality of harvested produce. You can control certain diseases by using tolerant or resistant varieties, while other diseases can be controlled only through the application ofa suitable chemical fungicide. Losses to several diseases can be minimized by planting tomatoes on well-drained soil with good water-holding capacity and fertility and by staking to keep fruits from contact with wet soil.

WILT DISEASES

Fusarium Wilt

Fusarium wilt is widespread and very damaging. The wilt-causing fungus, which insists in the soil for several years, is in most soils of Indiana where tomatoes have Previously been grown. The fungus, Fusar-ium oxysporum f. sp. lycopersici affects only cultivated and certain wild species. It enters through the roots and moves upward in the plant, growing in the water-conducting vessels. As the disease progresses, leaves yellow, wilt, and die. Woody tissues of in-fected stems show a characteristic brown coloration, which is easily observed by
either carefully removing a lower wilted leaf and sectioning the petiole or cutting away the epidermis of the main stem at ground level. Symptom development may first be localized on one portion of the plant but later spreads to other parts. Plants in early stages of infection may wilt during the day and recover at night.

The disease is favored by hot weather and soil temperatures of 82 to 84 degrees F. Although symptoms might appear at any time during the growing season, they generally appear shortly after bloom and/or set of the first cluster of fruit.

Fortunately, you can control tomato Fusarium wilt by growing resistant or highly tolerant varieties. Most seed catalogs specify which tomato varieties resist or tolerate Fusarium wilt. A few of the more widely used varieties that can be successfully grown on Fusarium infested soil include: Campbell 28, Campbell 1327, Spring Set, Heinz 1350, Heinz 1439, Burpee VF,
Ace VF. If you prefer a susceptible variety such as Beefsteak, Big Boy, Bonny Best, or Rutgers, be sure that disease-free seed or transplants are purchased and planted in an area where tomatoes have not been grown for several years.

Verticillium Wilt

Symptoms of Verticillium wilt resemble closely the symptoms of Fusarium wilt.

COOPERATIVE EXTENSION SERVICE, PURDUE UNIVERSITY, WEST LAFAYETTE, INDIANA