Midge Tolerant Wheat
Wheat midge infestations can reduce crop yield and lower the market grade of harvested grain, these losses can range from $20 to $75 per acre. Crop damage occurs when the midge larvae feed on the developing wheat kernel. Grain damage ranges from a slight change in shape, to a kernel that is completely shrunken and deformed, to complete abortion of the kernel. The damaged kernels can cause downgrading in wheat samples. Wheat midge is distributed throughout all wheat growing areas, where it lies in wait for optimal conditions to allow local populations to flourish. Although infestations have been primarily located in central Saskatchewan and western Manitoba, they are moving into Alberta as well.
Proper stewardship is necessary to preserve midge tolerance so farmers can continue to benefit from this technology. Farmers buying midge tolerant wheat are required to sign a Midge Tolerant Wheat Stewardship Agreement that limits the use of farm-saved seed to one generation past Certified Seed. This condition is critical because wheat midge may attack the refuge variety and the level of the refuge in farm-saved seed may change substantially over multiple generations. For example, under an extremely heavy midge infestation, the susceptible refuge variety could sustain up to 50 percent yield loss. To keep the refuge at the desired level of 10 percent of the plant population, it is necessary to limit the use of farm-saved seed to one generation past Certified Seed.
For refuge verification testing of Midge Tolerant Wheat please submit one 500 gram sample of untreated wheat seeds for each field or CSGA Crop Sequence Number to Discovery Seed Labs.