BS - Bacterial Speck

Scientific Name: Pseudomonas syringae

Type: Bacterium

Bacterial Speck is a disease that affects the growth of peppers and tomatoes. Symptoms include small brown spots brown in the center surrounded by a yellow ring on the leaves and curling of the leaves. In severe cases, the spots will spread to the tomato. It is caused by infected seeds and is spread by farm equipment, tools, workers, wind, and water. The infected plants should be removed to avoid further infestation. Cool moist conditions contribute to the development of the disease. The disease is favorable when temperatures are 63-75 F and usually occur when moisture and humidity are very high. Plan on using a 3 year crop rotation and avoid planting in the same location, year after year. Increasing space between the plants can help control and prevent the disease, as the disease can be spread from plant to plant in crowded conditions. Keep the fields weed free. Copper fungicides can help manage the disease. The best option is to use disease resistant varieties.

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.

ToMV – Tomato Mosaic Virus

Type: Virus - Tobamovirus

Tomato Mosaic Virus is a world-wide virus disease that affects the growth of peppers and tomatoes. Symptoms include dark green mottling or mosaic appearance on the leaves, yellowing of leaves, and stunting of the plant. The leaves tend to be fern-like and younger leaves may be twisted. The tomatoes will will be deformed and have yellow spots and the interior is brown. Infected plants usually wilt and die. It can cause significant yield loss and even total crops losses. It is a seed-borne virus and can be spread by farm equipment, workers, clothing, and contaminated tools. The disease can stay alive in dead plant material for long periods of time. The infected plants should be removed and destroyed to avoid further infestation. Plan on using a 2 year crop rotation and avoid planting in the same location, year after year, as the disease can survive in over winter on crop debris for 50 years. Keep your garden weed free. The best option is to use disease resistant varieties.

TYLCV – Tomato Yellow Leaf Curl Virus

Type: Virus - Geminivirus

Tomato Yellow Leaf Curl Virus is a disease that affects the growth of tomatoes. It is primarily found in California and Florida. Symptoms include severe stunting, yellowing of leaves, reduction in leaf size, and leaves curling upwards. Flowers do not develop fully and fall off. Tomatoes will drop off the infected plants. Severe infection can lead to the death of the plant. The disease can cause substantial yield loss and total crop loss. It is spread by the whitefly. The disease does not survive in soil, but can survive in weeds, so use weed management techniques. Plan on using a 3 year crop rotation and avoid planting in the same location, year after year. Keep the fields weed free. Proper tillage practices may be helpful in managing the disease. Covering plants with floating row covers of fine mesh can help protect plants from whitefly infestations. Home gardeners should carefully cover the plant with a plastic bag and tie at the stem at soil line to collect the entire plant and any whiteflies that may be on the plant, then cut off the plant at the soil line. Dispose of the plastic bag in the trash. Insecticides for can help control whitefly infestation. The best option is to use virus-free seeds and disease resistant varieties.

V – Verticillium Wilt

Scientific Name: Verticillium dahliae

Type: Fungus

Verticillium Wilt is a soil-borne disease that affects the growth of lettuce, peppers, spinach, and tomatoes. This disease is most common in the United States and Europe. In lettuce symptoms include wilting of the lower leaves and then the outer leaves turn yellow, wilt and die. Brown and black streaks appear on the taproot and crown The disease can cause substantial yield loss and total crop loss. It is a seed-borne disease that is spread by farm equipment, wind, and water. The infected plants should be removed and burned to avoid further infestation. The virus can live in weeds, so use weed management techniques. The fungus is very difficult to eradicate once it has been introduced into a field. Plan on using a 4 year crop rotation and avoid planting in the same location, year after year, and can survive in the soil for 14 years. Keep the fields weed free. Deep tilling may be helpful in managing the disease. Thoroughly clean equipment after working in a field. Fumigate fields with methyl bromide. The best option is to use virus-free seeds and disease resistant varieties