Key Features
- Wilt or dieback
- Vascular streaking
- Drought-like symptoms
Symptoms
The first symptoms of Fusarium wilt are foliar: infected seedlings have scattered yellow, unusually small, or curled leaves followed by tip dieback, wilt, and stunting as the disease progresses. Infections in mature plants result in wilting and drought symptoms. In wet conditions, the pathogen can cause dead spots on leaves and stems. Diseased root systems show a lack of fine root development. A key diagnostic sign of this disease is the production of cushion-like masses of oozing, pinkish-orange spores on the crown of young plants. Fusarium root and crown rot symptoms can be confused with those for Phytophthora, Rhizoctonia, and other soil-borne pathogens and abiotic conditions. Send diseased plant samples to a plant disease diagnostic clinic for analysis.
Biology
Fusarium is a common soilborne fungus. Although initial infections are usually random, spread within a landscape is most likely due to spores splashed from diseased seedlings during irrigation. Limited spread means infected plants will be very close to one another. Fusarium is present in most soils, and disease only develops when plants become stressed by drought, excess or too little fertilization, or other factors. The roots or crown are the most common sites for infection. When the plant dies, spores in the plant will become trapped in the soil, ready to infect the roots of susceptible plants.
Management Recommendations
Correct fertilization, irrigation, and soil drainage will increase plants' natural defense against the disease. Remove and destroy all Fusarium infected plants and plant debris to reduce the spread of disease and number of overwintering spores. Diseased plant material must be burned or removed from the property; composting will not kill the pathogen. Replace diseased plants with less susceptible plants. Protect seedlings and transplants with a thiophanate-methyl fungicide labeled for Fusarium control.
Effective Pesticides
Active Ingredients include: Thiophanate-methyl
Resources
- Not satisfied with ID? Contact the Purdue Plant and Pest Diagnostic Lab
- Sign Up for the Purdue Landscape Report
