De betekenis van de toestand van de grond voor het optreden van aantasting door het stengelaaltje (Ditylenchus dipsaci (Kuehn) Filipjev)

Field observations indicated that infestation by stem nematodes in rye and other crops depended on the type and condition of the soil. In laboratory experiments the mobility of these nematodes was greater in loams than in sands and much greater above a soil's moisture equivalent than at lower moisture contents. Great mobility could occur at both small and large pore volumes and average pore diameters. The mobility of stem nematodes in soil decreased as temperature increased and was often much greater in partially sterilized than in natural soil. A heat-labile water- soluble substance that reduced nematode activity could be extracted from certain soils in which nematode activity was small. A method of extracting nematodes, from plants was described.