By: Mitchell Japp, MSc, PAg, Provincial Specialist, Cereal Crops
Downgrading in cereal crops due to mildew can reduce profitability for producers. In any given year, some downgrading factors will be more common than others. Some causes might be hard vitreous kernels (HVK) in durum, pre-harvest sprouting or fusarium damaged kernels. This year, downgrading because of mildew will not be as severe as it was last year, as grading standards for mildew in nine milling wheat classes were relaxed in early October by the Canadian Grain Commission (CGC).
Mildew was a common downgrading factor for Canada Western Red Spring wheat samples received in the 2014 Harvest Sample Program. The CGC recognized that producers were losing income from downgrading due to mildew. Grading standards are not arbitrary – they are set based on safety, market acceptance and end-use suitability. Recognizing that lost income was significant, the CGC set out to determine if mildew standards were appropriate to meet end users’ needs.
The CGC studied the falling number, wheat and flour protein, milling yield, and water noodle dough colour, as well as gluten strength measurements. The study assessed wheat performance on samples where mildew was the only downgrading factor. After two years they found that mildew primarily affects the appearance of wheat, and the effect of mildew on durum semolina was negligible.
The 2016 harvest has been challenged by frequent precipitation – both rain and snow. Mildew occurs when kernels are affected by fungi that develop when moisture is excessive. Because the implications are significant to producers, the Western Standards wheat sub-committee recommended the mildew standards be adjusted immediately, but not retroactively to grain already delivered. Normally, the CGC introduces changes like this at the beginning of the next crop year, so this is welcome news for a wet harvest.
Mildew is assessed according to the degree of soundness definition.
Affected classes include:
- Canada Western Red Spring (CWRS);
- Canada Western Hard White Spring (CWHWS);
- Canada Western Amber Durum (CWAD);
- Canada Western Red Winter (CWRW)
- Canada Western Soft White Spring (CWSWS);
- Canada Western Extra Strong (CWES);
- Canada Prairie Spring White (CPSW);
- Canada Prairie Spring Red (CPSR); and
- Canada Northern Hard Red (CNHR).