WHEAT
Midge Tolerant Wheat
Midge tolerant wheat varieties are a tool in the pest control toolbox which protects growers from damage caused by the orange wheat blossom midge . Orange wheat blossom midge are a pest which affects all classes of wheat by laying eggs in the emerging heads . The subsequent larvae feed on the developing kernels causing them to shrivel , crack and become deformed . Damaged kernels are often mistaken as frost damage when graded for sale . The result is reduced crop yields , lower grading of the harvested grain and ultimately lower profitability for the grower .
Primary control of the orange wheat blossom midge is by seeding midge tolerant wheat varieties . Current insecticidal control options are very limited and are only effective on the adult midge versus the larvae which causes the actual damage . Midge tolerant wheat varieties have the Sm1 gene which stops midge larvae from feeding on wheat kernels . All midge tolerant wheat varieties are sold as varietal blends where 10 per cent of the seed is a refuge variety that is not midge tolerant . This is an important characteristic that slows midge communities from overcoming the tolerance trait by reducing selection pressure for resistant individuals .
density in soil surveys taken each fall . Larvae can stay dormant in the soil for several years but growing seasons with at least 25 mm of cumulative rainfall in May will trigger adult emergence . Midge damage in previous crops can also be an indicator of future pressure .
With the volatile growing seasons that have plagued Western Canada in recent years , seeding a midge tolerant wheat variety provides peace of mind against orange wheat blossom midge . Midge tolerant wheat varieties protect the bottom line .
WHEAT
Midge tolerant wheat varieties come with a stewardship agreement , which allows the use of farm-saved seed only one generation past certified . This is important because it ensures the interspersed refuge of the non-midge tolerant variety remains at a sufficient density . This stewardship agreement is evergreen , so a grower is only required to sign it once .
To help assess risk for orange wheat blossom midge , provincial authorities in Alberta and Saskatchewan have developed forecast maps . Forecasts are based on larval
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