F – Fusarium Wilt (Race 1)

Scientific Name: Fusarium oxysporum

Type: Fungus

Fusarium Wilt, Race 1, is a fungal disease that affects the growth of tomatoes. It is one of the most devastating of all soil-borne diseases. Race 1 is the most widely found throughout the United States, especially in warm regions of the country. It attacks the roots of the plants and moves up the stems. Symptoms include yellowing and browning of the older bottom leaves, stunting, and wilting. Often the entire plant will die. Usually little or no fruit develops. The infected plants will produce inferior and unmarketable tomatoes. It can cause significant yield loss and even total crops losses. If you stick with Fusarium Wilt Resistant tomato varieties you don’t have to worry. Many of the older heirlooms don’t have any resistance to the disease, so if you grow these then you should keep an eye out for it. The infected plants should be removed and burned to avoid further infestation. Plan on using a 5 to 7 year crop rotation and avoid planting in the same location, year after year, as the disease can survive in the soil up to 10 years. The best option is to use disease resistant varieties.

N – Root-Knot Nematode

Scientific Name: Meloidogyne spp.

Type: Parasites

Nematodes are soil dwelling parasites that feed on plant roots and affect cucumbers, okra, peppers, squash, and tomatoes. Symptoms include yellowing of the leaves, wilting, and stunting of the plant. The plant will have galled and decayed roots. Nematodes are most active when soil temperatures are 85 - 95 F and usually occur when the soil is moisture. Plan on using a 3 year crop rotation and avoid planting in the same location, year after year. Nematodes are most active in warm soils and they need water to thrive so take advantage of summer’s heat to wither them away. Withhold water from nematode infested areas of the garden and turn or till the soil every 7-10 days during the summer to expose nematodes to the drying effects of the sun. Proper tillage practices may be helpful in managing the disease. Certain types of marigolds work by excreting a substance that is damaging to nematodes as well as trapping them in their roots and preventing reproduction. Elbon rye is an effective nematode control that can be planted as a cool season cover crop that is turned under in early spring. The use of soil fumigants like Vapam has been helpful and a fungicide called Actinovate can also be helpful in managing the lowering of the nematode population. Using transparent plastic mulches for 4 to 6 weeks have been shown to kill nematodes. The best option is to use disease resistant varieties.

TMV – Tobacco Mosaic Virus

Type: Virus - Potyvirus

Tobacco Mosaic Virus is a world-wide virus disease that affects the growth of eggplants, peppers, and tomatoes. Tobacco mosaic virus may cause significant losses in the field and in the greenhouse. The virus does not usually kill the plant, but it does cause damage to flowers, leaves, and the tomato. Symptoms include stunted or dwarfed plants, yellow-green mottling, blistering of the leaves, a light-green and dark-green mosaic pattern on the leaves, leaf distortion and curling of the leaves, fernleafing, and reduced growth rate and yields. Blooms may have brown streaks. Pepper plants may have yellow spotting on the leaves. Slightly sunken brown rings will appear on tomatoes. The virus is spread primarily by mechanical methods. The virus is not spread by aphids. Smokers can infect plants by handling them. Gardeners contaminate the plants when they touch tobacco products or infected plants or weeds and spread the virus to healthy plants. The virus can stay alive in dead plant material for long periods of time. It can survive on infected seeds, plant debris, and even clothing for months or years. Tobacco mosaic is one of the most highly persistent tomato diseases because it can remain viable for many years and is able to withstand high heat. The virus can survive for up to 50 years in dried plant debris. The infected plants should be removed and buried or burned to avoid further infestation. Plan on using a 3 year crop rotation and avoid planting in the same location, year after year. Keep your garden weed free. Wash your hands thoroughly and disinfect tools. Try to avoid smoking while working in the garden. Spraying plants with 20 percent nonfat dry milk has been shown to be somewhat effective in preventing the spread of the virus. The best option is to use disease-resistant varieties.