OBSERVATIONS ON THE CONTROL OF POTATO‐ROOT EELWORM (HETERODERA ROSTOCHIENSIS WOLLENW.) UNDER GLASS BY D‐D* AND SOLUBILIZED p‐m CRESOL†

Abstract

D-D injected at 400 Ib.jacre into light loam in two glasshouses in Wiltshire killed 03.9 and 91.5 "4 of the eelworm population, respectively, in the 0-9 in. soil layer.Growing tomatoes in pots in house I on top of the treated soil resulted in an overall fall in eelworm population to approx. one-seventh of its original value. Tomatoes grown in the treated soil in house z built up the population to approx. J $ times its original level.Combined treatments, using solubilized cresols as a surface seal instead of water, increased the kill in the 0-3 in. soil layer, but a higher degree of kill here is still required.All populations have been estimated by the root diffusate technique.

The efficacy of fumigation of nematode‐infested soil following different methods of soil sealing

“…Increased nematode control by incorporation of a second toxicant in the surface of fumigated soil has been reported by several workers. Peters (1955) and Stone (1956Stone ( , 1957 improved control of potato cyst nematode with dichloropropane-dichloropropene by drenching the soil with a water-soluble nonvolatile chemical, p-m-cresol. Because of difficulty in handling this material and the large volume of water needed for drenching, the method has not been widely used.…”

“…Large amounts of water are needed for sealing the surface and as with rolling wetting is diflicult to practise effectively. Methods of seahng chemically have included drenching the soil surface with solubilised ;7-w-cresol (Peters, 1955;Stone, 1956Stone, , 1957 and incorporating dazomet in the surface layer (Seinhorst, 1973;\yhitehead et al, 1973). This paper reports the effect of sealing fumigated soil surfaces with easily applied resin sprays and of incorporating dazomet with the Rumptstad Combiject during the injection of a liquid fumigant.…”