Effects of soil fumigation on disease incidence, growth, and yield of spring wheat

SUMMARY Plots were fumigated with various amounts of D‐D or 85% dazomet dust and sown with spring wheat given various amounts of nitrogenous fertilizer. Dazomet increased yield and decreased take‐all disease in the first crop after application, but increased the disease in the second crop. Although D‐D increased take‐all slightly, it increased yield in 1966, but in 1967 it decreased yield and its use was associated with a severe ear deformity. Fumigation had little effect on eyespot, sharp eyespot, root browning ( Fusarium spp.), or browning root rot ( Pythium spp.), but decreased nematode damage where nematodes were numerous.