THE INFLUENCE OF ORANGE WHEAT BLOSSOM MIDGE (Sitodiplosis mosellana Géhin) DAMAGE ON HARD RED SPRING WHEAT QUALITY AND THE EFFECTIVENESS OF INSECTICIDE TREATMENTS

Abstract

Orange wheat blossom midge damage can impart serious loss of quality to Canadian hard red spring wheat. The extent of wheat quality deterioration is highly variable and not well related to degree of visual midge damage. Midge-damaged hard red spring wheat exhibits very high protein content, reduced flour yield, dark flour color, increased flour ash, weak sticky dough properties, low baking absorption and poor bread quality. Midge-damaged wheat contains normal levels of α-amylase and proteolytic enzymes. Severely midge-damaged wheat exhibits inferior gluten protein quality, but the cause remains obscure. The poor baking quality of severely midge-damaged wheat is associated with an unusually low sodium dodecyl sulfate (SDS) sedimentation volume. Samples with visual evidence of midge damage can be rapidly screened for quality defects on the basis of protein content and SDS-sedimentation volume. Aerial applications of Cygon and Lorsban to fields of midge-infested hard red spring wheat significantly reduced visual midge damage, and significantly reduced the extent of wheat quality deterioration.Key words: Midge (orange wheat blossom), wheat (spring), insecticide treatment