By Top Crop Manager
Nov. 30, 2015 - The wheat stem sawfly forecast and wheat midge forecast maps are now up on Alberta Agriculture and Forestry (AF)'s website.
According to Scott Meers, insect management specialst with AF at Brooks, the risk of economically significant sawfly populations in 2016 will be limited to only a few areas in the province.
"For the wheat stem sawfly, we go into the wheat fields after harvest, look at four spots and count the number of stems that are intact and the number that have been cut by the sawfly," he says. "This system gives us a percentage cut, and from that we can make a fairly good forecast on what to expect for the next year."
Meers says the forecast calls for fairly low numbers, especially in the traditional areas such as the M.D of Acadia, County of Forty Mile and the Special Areas, although individual fields may vary.
"We found a fairly significant hot spot in the eastern portion of Willow Creek and the western portion of Lethbridge counties where the two are side-by-side. There are fields in that area that absolutely should be have solid-stem wheat planted there next year if wheat is to be planted. Numbers are high, but not extreme like during the height of the outbreaks in the early 2000s. However, there are high enough that there could be yield losses."
As for wheat midge, Meers says during the past year, samples were taken from over 300 fields. "We aim for a minimum of five soil samples per county from wheat-heavy counties and a few less samples from where wheat is less prevalent. This gives us a good read on what the general trends are."
Overall, he says the survey shows wheat midge are the lowest seen in a number of years, probably because wheat midge tends to do better in wet years, and this last one was quite dry. "However, there is a hot spot for the second year to the east of Edmonton, and a residual population in the Falher area where there was a lot of wheat midge two years ago," Meers says.The wheat stem sawfly map is available on AF's webpage as is the wheat midge map. Meers adds that the rest of the forecast maps should be up in mid January.