Soil Sampling for Potato Root Eelworm Cysts

The National Agricultural Advisory Service (Advisory Entomologists) has adopted a uniform soil‐sampling technique for potato root eelworm. In Part I the recommended technique is quoted in full. In Part II an account is given of some experimental sampling done by the Advisory Entomologists, on which the recommendations are partly based. In trying to estimate the average cyst content of the soil of a field, a statistical problem is encountered of deciding on an adequate sampling procedure. A similar problem was investigated in the wartime wireworm survey, but the rather different features of eelworm sampling call for fresh consideration of points of detail.