Beet eelworm (Heterodera schachtii Schm.) in East Anglia, 1934‐1943

Abstract

Observations made on the beet eelworm (Heterodera schachtii Schm.) between 1934 and 1943 are described. This eelworm confines its attacks to crop plants of the families Chenopodiaceae and Cruciferae. Cysts similar to those of the beet eelworm have been recorded on many weeds. Records of beet eelworm on weeds of the above families are probably authentic, but those of other families require confirmation. In the field, the four so‐called strains of Heterodera schachtii (viz. the beet, oat, pea and potato strains) behave as distinct species. Some evidence is given for the possible existence of a cruciferous strain.Attempts were made to ascertain the distribution of beet eelworm in East Anglia. A general search was conducted throughout the area and special attention paid to beet‐sugar factories, beet‐loading sites, sewage farms, and to certain important beet‐growing areas located in the Isle of Ely and neighbouring counties. Throughout the search, diagnosis was based on the finding of lemon‐shaped cysts on the roots of sugar beet, red beet or mangolds. Details of our present knowledge of the distribution of beet eelworm are given. It appears to have been present in Britain for a considerable time but is not yet widely disseminated.The spread of beet eelworm is considered in detail, and it is concluded that the establishment of the beet‐sugar industry has led to a considerable increase in the rate of spread.Measures for the control of beet eelworm are described. In the early days of the industry, beet was grown without regard to rotation, thus providing conditions similar to those existing in Germany before 1870 when 'beet‐sickness was becoming a serious problem. The first control measure was the introduction of a clause into contracts forbidding the growing of beet after beet or mangolds. More effective measures, which were adopted in 1939, are described. In 1943, the Sugar‐Beet Eelworm Order was issued enforcing these measures over a wide area and extending them to cover all susceptible crops.Effective control measures may result in a reduced rate of spread of the beet eelworm but cannot eliminate it.