Fusarium orthoceras produced necrosis of succulent root tissues of soybean seedlings and infected tips of lateral roots of older plants. Pods and seeds were most susceptible to fungus penetration after maturity. High relative humidity was necessary for infection of seeds. Maximum stand reduction and yield loss under field conditions were obtained when seeds were sown in Fusarium-contaminated soil before rains. In a greenhouse the disease was most destructive when plants were grown in soil at 100-percent water-holding capacity at 21° C. The disease was less damaging to plants grown in soil at the same moisture level at 27°. Seedlings grown in contaminated soil at 100-percent water-holding capacity at 21° for three weeks wilted permanently in a few hours when the temperature was raised to 33°, whereas plants in noncontaminated soil did not wilt.
Proceedings of the Iowa Academy of Science
©1961 Iowa Academy of Science, Inc.
"Fusarium Blight of Soybeans,"
Proceedings of the Iowa Academy of Science, 68(1), 106-113.
Available at: https://scholarworks.uni.edu/pias/vol68/iss1/16