Integrated control of potato cyst nematodes using small amounts of nematicide and potatoes with partial resistance

Abstract

SUMMARY The control of potato cyst nematode (PCN) by less than approved amounts of nematicide combined with partially resistant potato clones was studied in a series of field experiments. On a site heavily infested with Globodera pallida only the most resistant clone (12380ac2) decreased the population density in untreated soil. With aldicarb at its full approved rate (3·36 kg ha ‐1 ) numbers of PCN were decreased under all the genotypes, including the non‐resistant Maris Piper. Aldicarb at 1·68 kg ha ‐1 significantly decreased populations on all clones except 12380ac2. Aldicarb at 0·84 kg ha ‐1 still significantly decreased population densities and multiplication rates of G. pallida on two clones with intermediate resistance (12243acl and 11233ab22). At two G. rostochiensis sites with light infestations nematode multiplication rates were greater and the control given by aldicarb and partially resistant genotypes of potato was not as great as that at the site with G. pallida. Tuber yields were not increased by the application of aldicarb at the G. rostochiensis infested sites. However, at the site heavily infested with G. pallida the yield of the most intolerant genotype (12380ac2) was increased seven‐fold by the full rate of aldicarb (3·36 kg ha ‐1 ) and four‐fold by the quarter rate (0·84 kg ha ‐1 )‐Yield of the most tolerant genotype (12243acl) was unaffected by the application of aldicarb.