Published online by Cambridge University Press: 27 March 2009
Potato cyst-nematode, Globodera rostochiensis, was controlled in a three-course rotation (potatoes-sugar beet-barley) by treating the soil with an effective nematicide before growing susceptible Pentland Crown potatoes, or by growing Maris Piper potatoes, resistant to the nematode. In moderately infested sandy loam, Maris Piper potatoes grew and yielded much better in soil treated with a nematicide than in untreated soil. Maris Piper outyielded Pentland Crown only in years with ample rain in August. Sugar beet and barley in some years yielded better after Pentland Crown than after Maris Piper potatoes. Yield loss in Pentland Crown due to potato cyst-nematode varied greatly in the same field. The nematode was controlled better by 5·6 kg oxamyl/ha, or by 448 or 672 kg dazomet/ha, than by 448 kg Telone/ha. Large soil populations of G. rostochiensis declined faster under sugar beet and barley than small soil populations did, suggesting action of a predator or pathogen.