Studies of cereal nematode populations and cereal yields under continuous or intensive culture

In a field experiment on infested sandland from 1955 to 1967, numbers of Heterodera avenae increased only in 1957 and then decreased under both continuous and rotational spring oats (1955-62) and subsequently under spring barley (1963-67). Fluctuations in numbers of Pratylenchus neglectus and Trichodorus primitivus were recorded from 1963 to 1967. Cereal grain yields were generally unsatisfactory, but were consistently higher for cereals grown in rotation rather than continuously. Extra nitrogen fertilizer gave slightly improved yields with higher post-cropping numbers of H. avenae.