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Responses of summer cereal aphid populations to reduced rate aphicide applications in field plots of winter wheat |
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| Authors: | J N Oakley‡ S A Ellis M Watling† K F A Walters‡ J E B Young† |
| Institution: | ADAS Rosemaund, Preston Wynne, Hereford, HR1 3PG, U.K.,; ADAS High Mowthorpe, Duggleby, Malton, North Yorkshire, YO17 8BP, U.K.,; ADAS Boxworth, Boxworth, Cambridge, CB3 8NN, U.K. and; CSL, Sand Hutton, York YO41 1LZ, U.K. |
| Abstract: | Abstract 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. |
| Keywords: | Aphicides application rate Metopolophium dirhodum population development Sitobion avenae yield |