CR – Clubroot
Scientific Name: Plasmodiophora brassicae
Type: Fungus
Clubroot is a world-wide fungal soil-borne disease that affects the growth of cabbage, cauliflower, broccoli, Brussels sprouts, kohlrabi, radishes, rutabaga, tomatoes, and turnips. This disease can cause severe crop yields and total crop loss. The fungus infects the plant through root hairs or wounds. Symptoms include wilting and yellowing of leaves. Young plants are stunted and may die. The roots are usually swollen and distorted (clubbed). The disease is spread by farm equipment, wind, and water. The infected plants should be removed and burned to avoid further infestation. The disease is favorable when temperatures are 54-81 F and usually occur when soil is moist. The disease is primarily associated with acid soils. Plan on using a 7 year crop rotation and avoid planting in the same location, year after year, as the disease can survive in the soil up to 20 years. Use proper weed control techniques. Proper tillage practices may be helpful in managing the disease. It is essential that hydrated lime be added each year to the soil unless the soil pH exceeds 7.5. Thoroughly clean equipment after working in a field. Plant crops in well drained soil. The best option is to use disease resistant varieties.
FCRR– Fusarium Crown & Root Rot
Scientific Name: Fusarium oxysporum f. sp. asparagi, Fusarium proliferatum, and Fusarium moniliforme
Type: Fungus
Fusarium Crown & Root Rot is a devastating world-wide soil borne disease that affects the growth of asparagus and tomatoes. The disease affects the roots. Symptoms include wilting, stunting, yellowing, and dry rot of the crowns. Often the crown turns a brown color when it is infected with the disease and then rapidly dies off. Once the plant is infected, it is extremely difficult to manage the disease once the fungus is established in the field. Plan on using a 5 year crop rotation and avoid planting asparagus in the same location, year after year as the disease can survive in the soil for a long time. The best option is to use disease resistant varieties.
R - Rust
Scientific Name: Puccinia asparagi, Puccinia sorghi
Type: Fungus
Rust, also known as Common Rust, is a world-wide soil borne disease that affects the growth of asparagus, cantaloupes & melons, corn, and lettuce. It is one of the most destructive disease in growing asparagus in the United States. The disease affects the ferns on asparagus. Lesions develop and turn cream-orange color, then turn a reddish-brown color, then eventually turn a brick red or rust color. During the winter the lesions will turn a black color. Severe infestation stunts or kills young asparagus shoots. The infected plants should be removed to avoid further infestation. When corn is infected the disease affects the upper and lower leaf surfaces, where small specks appear on the leaves, then develops into small tan spots, and distinguished by cinnamon-brown pustules. These pustules blister and turn dark brown to black late in the season. Corn stalks are weakened and stalk rot potential increases. Significant damage to upper leaves results in significant yield losses. Common rust spreads by windblown spores. The disease is also favorable cool and moist conditions when temperatures are 68-72 F, and usually occurs when there is nine hours of wet weather. The best option is to maximize air movement between the plants and to use disease resistant varieties.