The number of generations of Heterodera schachtii completed on oilseed rape ( Brassica napusL.) during the UK growing season

The number of generations completed by a UK field population of Heterodera schachtiion winter and spring oilseed rape (OSR; Brassica napusL.) during the growing season of 2010/2011 was investigated. The experiments were conducted in pots outdoor using UK OSR winter cultivars (cvs) Flash and Castille and spring cvs Belinda and Heros. The results indicated that temperature was crucial in determining the number of generations completed on OSR during the growing season. At least one generation was completed on cv. Castille, whilst two generations were completed on cvs Flash, Belinda and Heros during the growing season. Development of H. schachtiiwas faster on hybrid OSR cvs Flash and Belinda, suggesting that the hybrids were better hosts of H. schachtiithan the conventional cvs Castille and Heros. Cultivar Flash was more susceptible to H. schachtiiinfection than cv. Castille, while cv. Belinda was more susceptible than cv. Heros. However, no major plant growth differences were observed between the cvs investigated. This is the first report on the number of generations of H. schachtiicompleted on current cultivars of OSR in the UK