Computer mapping of records of beet cyst nematode (Heterodera schachtii), 1928–77

Early records of beet cyst nematode ( Heterodera schachtii Schmidt) in Britain and the history of regulatory measures to control it are summarized. Data collected between 1928 and 1976 were computer mapped on a 10 km grid scale to illustrate the cumulative distribution of beet cyst nematode in Britain. The distribution of the nematode was compared with that of its principal host, sugar beet. Data collected between 1962 and 1977 in East Anglia were computer mapped on a 1 km grid scale to show the detailed distribution of beet cyst nematode in that area. The advantages of computer-generated distribution maps over manually produced maps are discussed.     

Surveys of beet cyst nematode in England 1977–80

Surveys of sugar beet crops for beet cyst nematode ( Heterodera schachtii Schmidt) in seven selected areas of England have provided data on distribution of the pest and on some factors affecting its occurrence. These data were mapped by CAMGRID computer program.
Infestations occurred mostly on the East Anglian fenland (14% of fields infested) and in this area were more frequent nearer the sugar beet processing factory. In the remaining areas the few infested fields (5% or less) were generally scattered but a small concentration of infestation occurred in the West Midlands in an area of intensive horticulture with frequent brassica crops. The survey data did not support the view that beet cyst nematode infestations occur more frequently near access points to the crop. In the surveyed areas frequency of host crops appears to be more important than soil type in determining the likelihood of infestation.