BW - Bacterial Wilt
Scientific Name: Erwinia tracheiphila
Type: Bacterium
Bacterial Wilt is a disease that affects the growth of cantaloupes & melons, cucumbers, eggplants, gourds, pumpkins, squash, and tomatoes. Symptoms include wilting and drying of individual leaves. As the leaves wilt and shrivel, stems may dry out suddenly. Later, wilting spreads to entire branches and vines. Wilting will occur during the middle of the day during periods with high water stress. The vine may recover at night. Eventually, however, the entire vine will wither, collapse, and die. Bacterial wilt is spread from plant to plant through cucumber beetles that feed on cucumbers. The infected plants should be removed to avoid further infestation. Plan on using a 3 year crop rotation and avoid planting in the same location, year after year. Use insecticides like Admire, Platinum, or Sevin in the spring, between April and June, before the cucumber beetles have a chance to lay eggs. 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.