Fusarium is a soil-born fungus that is found throughout the U.S., especially in warm regions of the country. It has been found that plants that are in sandier soils are more susceptible to the disease. Additionally, high nitrogen levels accompanied by low potassium levels in soil increase a plants susceptibility to Fusarium. Symptoms and Diagnosis Fusarium often causes yellowing on one side of the plant or leaf. Yellowing of the leaves begins with the older, bottom leaves, followed by wilting, browning, and defoliation.
Growth is stunted, and little or no fruit develops.
Brown, vascular tissue can be found when the infected stem is cut at its base. Infected plants often die before maturing. Life Cycle Fusarium fungi survive in the soil or on plant debris for up to ten years. Disease development is favored by warm soil temperatures and symptoms are most prevalent when temperatures range from 80-90 degrees Fahrenheit. The fungi enter the plants through their roots and are then spread throughout the plant by the plant's water-conducting vessels.