Effect of soil fumigants on Fusarium wilt and nodulation of peas (Pisum sativum L.)

Chloropicrin, dazomet, formaldehyde, and D-D soil treatments all decreased the incidence of Fusarium wilt in a wilt-susceptible variety of pea grown in wilt-infested soil, but only chloropicrin and dazomet gave satisfactory control of the disease. All four fumigants decreased root nodulation, but no adverse effects on plant growth were detected. With dazomet, formaldehyde, and D-D, decreased nodulation is largely attributed to the extra soil nitrogen mineralized, whereas with chloropicrin the almost complete suppression of nodulation probably reflects the lethal effect of this material on the Rhizobium bacteria.