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Fig 14. Winter wheat showing FHB, Winkler. Fig 15. Winter wheat heads showing FHB, Photo courtesy Tao Wang, CargillAgHorizons . from 15% to 100% spike infection.
Photo Courtsey Earl Bargen,MAFRD.
Minute leaf spots are showing up on flag leaves in spring wheat; some of the fields are just about to reach the critical FHB sensitive stage. If the forecasts indicate that the critical flowering period will coincide with high FHB risk – then FHB control fungicide application will be helpful. If the forecast risk for FHB is low (based on weather or flowering), then a flag leaf application could be considered, depending how the lower crop canopy and the flag leaf look - with respect to leaf diseases. Warm and humid conditions can still favour leaf diseases.
Emergence of Wheat Midge
The following maps show the emergence of wheat midge and its key parasitoid Macroglenes penetrans. So far there have been no reports of high levels of wheat midge in Manitoba, and emergence may still be in the early stages in northern Manitoba and the northern Interlake.
A reminder that once wheat has flowered (produced anthers) it is no longer an acceptable host for wheat midge and scouting for wheat midge would not be necessary in these fields. Wheat midge that are present would still be flying in these fields, but the crop is no longer an acceptable host for the larvae.
Also note that the emergence of the parasitoid is synchronized quite well with that of the wheat midge. So hopefully when the wheat midge are emerging the parasitoids will be waiting to lay their eggs into the eggs of the wheat midge.