If you have walked into your vegetable or flower garden and yesterday’s beautiful plant suddenly looks a little wilted, your plant may have a disease called Verticillium Wilt or one called Fusarium.
Verticillium willt is caused by the fungus Verticillium albo-atrum. It is a disease of many vegetable and fruit crops as well as ornamentals and shade trees. It affects over 300 plant species. The soil-born fungus enters the plant through the roots and spreads up though the water-conducting vessels of the roots, stem or trunk. This results in partial or complete plugging of the vascular system. With limited water supply, leaves begin to wilt on sunny days and recover at night. Tomato and potato plants may recover somewhat but are usually weak and produce fruit of low quality. Peppers typically collapse rapidly and die.
Fusarium Wilt is a soil-borne fungus. Plants can be infected at all stages of development. Symptoms begin many times in older vine plants by wilting during the hottest part of the day and recovering during the night. They are often stunted and yellowed and leaves have dead areas. Fusarium Oxysporum is well adapted to life in the soil and survives season to season in old diseased vines. It grows at soil moisture and temperature favorable for vine crop growth and can live in the soil for many years.
There seems to be no magic cure for these soil-borne funguses. There are, however, several steps you can take to reduce the likelihood of your plants becoming infected with Verticillium or Fusarium Wilt and managing the disease if they unfortunately do become infected.
1. Plant disease resistant varieties labeled V (for Verticillium) and F (for Fusarium). Designations usually shown in seed catalogues and on plant containers
2. Fertilize and water plants to keep them healthy and vigorous, especially during hot weather. Do not over-irrigate, especially early in the season.
3. A long crop rotation (4-6 years) is necessary because Fusarium and Verticillium fungi are widespread and can stay in the soil for several years.
4. Keep rotational crops weed-free as there are many weed hosts of Verticillium and Fusarium.
5. Whenever possible, remove and destroy infested plant material after harvest.
There is a wealth of information available on these complex diseases.
The Purdue Extension Office welcomes gardening and agricultural questions. The Purdue University Cooperative Extension Service can be reached at (260) 499-6334 in LaGrange County.