EXPERIMENTS WITH MOLD INOCULATION IN COTTON ROOT ROT AREAS

Charles Thorn and Marie B. Morrow, Bureau of Plant IndustryU. S. Department of Agriculture, Washington, D. C.

This preliminary work follows upKing's hypothesis that continuous produc-tion of cotton on certain neutral-to-alka-line soils has brought about an unbalancedsoil population in which Phymatotrichum(cotton root rot) has become dominant.Surveys in rot-infested areas showed theabsence, or only sporadic presence, of thespecies of Trichoderma and other molds

which have been designated antagonistic inrecent investigations. A selected seriesof molds including Trichoderma, were inoc-ulated into experimental plots of cottonand recovered sufficiently consistently atthe point of inoculation to justify furtherexperiments toward such utilization in con-trol of detrimental species.