Integrated control of wheat blossom midge - HGCA

MATERIALS AND METHODSVarietiesExperiments were conducted at five sites each year (Table 3). In 2001/02 a selection of varieties grown in1993 variety trials (Oakley 1994) were included to represent the range of susceptibility found at that time.This was done to assist prediction of field performance of similar varieties against the assessments of theCereal Quality survey results from 1993 and 1994 (Oakley 1994 and 1995). The mean value of visible graindamage found relative to the 1993 control varieties is shown in parentheses:Beaver (120), Cadenza (92), Hereward (93), Hussar (70), Lynx (165), Rialto (142), Riband (88), Soissons(129) and Spark (75).In each year the RL control varieties were grown plus the industrial partners’ recommended varietiesincluding other lines showing potential resistance to wbm (Table 4).In 2001/2 two replicates of each variety were sown in a randomised block design. In the succeeding yearsfour replicates were sown, two of which were treated with chlorpyrifos at 450 g ai/ha when the majority ofvarieties were between GS 55 and 59.Table 3. Experimental sites - location, sowing date and attack on control varietiesLocation 2001/2 2002/3 2003/4ADAS Boxworth, Cambridge 2 November 15 October 29 OctoberAdvanta, Wolferton, Norfolk 9 October 11 October 1 OctoberElsoms, Weston, Lincolnshire 18 October 5 November 28 SeptemberTAG, Morley, Norfolk 19 October 9 October 20 OctoberNickersons, Maldon, Essex 6 OctoberAssessment of wheat blossom midge attackSampling and storage• Samples consisted of 10 ears per plot taken in two groups of five. One ear was chosen at random at twopoints and the four nearest ears included in the sample.13