Responses of summer cereal aphid populations to reduced rate aphicide applications in field plots of winter wheat
1 Recommended and reduced rate applications of pirimicarb and alpha-cypermethrin were applied to winter wheat crops to control summer infestations of grain aphid (Sitobion avenae) and rose-grain aphid (Metopolophium dirhodum).
2 Aphid numbers were assessed weekly and the yield response to treatment application was compared with accumulated aphid days on the crop.
3 Responses to aphicide treatment varied between sites according to variations in the subsequent development of aphid populations under varying weather conditions and differential pressures from aphid natural enemies.
4 Alpha-cypermethrin treatment reduced spider density at most sites, and also resulted in a resurgence of aphid populations at three sites.
Document Type: Research Article
Affiliations: 1: ADAS Rosemaund, Preston Wynne, Hereford, HR1 3PG, U.K., 2: ADAS High Mowthorpe, Duggleby, Malton, North Yorkshire, YO17 8BP, U.K., 3: ADAS Boxworth, Boxworth, Cambridge, CB3 8NN, U.K. and 4: CSL, Sand Hutton, York YO41 1LZ, U.K.
Publication date: August 1, 2005