SURVEYS OF BEET CYST NEMATODE (HETERODERA-SCHACHTII-SCHMIDT) IN ENGLAND

In 1977, all restrictions on cropping imposed by successive Beet Eelworm Orders, in force since 1943, were removed. To monitor the effect of this relaxation, surveys for beet cyst nematode (Heterodera schachtii), were undertaken annually between 1977 and 1988 in seven sugar-beet-growing areas thought to be most at risk from the nematode. In Area 1 (approximately the "Scheduled Area" of the Beet Eelworm Orders, comprising mainly the East Anglian fens), detectable infestations increased from 8.3% of fields sampled in 1977 to 34.0% in 1985, and thereafter stabilised at about 30% of fields sampled. Detectable infestations increased in only one other Area (West Norfolk and West Suffolk, adjacent to Area 1). The incidence of detectable infestations was directly related to the length of the break between host crops. Soil-applied pesticides, principally targetted at arthropod pests, had no apparent effect on the incidence of detectable infestations of H. schachtii.