Garden vegetables are affected every year by diseases that cause unsightly appearance and possibly ruin the entire crop. You can reduce the risk of loss by using a combination of disease prevention methods. Many diseases are preventable, and can be kept in check by ridding the garden of debris. If you run across an infected plant, it is best to remove it by the roots to keep the problem from spreading to neighboring plants.
This fungus is common in ripe tomatoes, but can also affect green tomatoes. The first signs of anthracnose are spots that appear as water spots under the skin. Over time, they turn dark and become black. If you are quick to apply a fungicide when you first notice these spots, it may be effective in controlling the disease. Be sure to kill off all the fungus, as plants can become reinfected. After harvest of healthy fruits, clean up and destroy all debris.
Fusarium wilt is a fungus that attacks watermelons, cabbages, tomatoes, peas, beans and sweet potatoes. It is recognized by yellowing of the lower leaves on only one side of the plant. There are also two streaks brownish in color in the roots when they are split lengthwise. Plants affected by this disease are typically wilted and stunted. The best control is to use wilt-resistant varieties. When needed, remove infected plants and destroy.
Powdery mildew is a common disease that affects a large variety of vegetables and fruits. White or gray spots usually appear on older leaves first before spreading. They band together and form powdery splotches. Don't over-fertilize, and be sure to wash the affected plants thoroughly, as water kills the spores. Powdery mildew typically appears late in the growing season. Injury to the plant by this disease can include leaf distortion, stunted growth, yellowing leaves and death of plant tissue. Using a fungicide will generally take care of the problem. Begin applying as soon as the first white patches are noticed. You may want to contact your local Cooperative Extension Office for more information.