Preharvest use of glyphosate on malting barley “should not be a recommended practice”, according to the conclusion of a recent field trial report, because it risks “the quality and residue status” of the grain.
The study was conducted to assess preharvest use on barley at different rates and stages of crop maturity. The unexpected finding was that maximum residue limits (MRLs) of glyphosate were exceeded, “even when glyphosate was applied at the recommended level … and time”. In other words, even when spray label directions were followed.
The report, Effects of different timing and rate of glyphosate application on the residue level, grain quality, and processing performance of two Canadian malting barley varieties, was written by scientists from Agriculture and Agri-Food Canada and the Canadian Grain Commission, and partially funded by the barley industry to better understand the effect of spraying on their crop.
A second article in the Canadian Journal of Plant Sciences was based on the same data, and underlines the findings. The article, The effects of pre-harvest glyphosate rate and timing on yield and pre-malt quality of malting barley, concludes that “alternative agronomic practices” would better serve the barley industry, and also argues that the physical descriptors on labels for when to spray are inadequate.
The conclusion of the reports supports the position already taken by the Canadian malsters on preharvest use.
Reports show premise of PMRA wrong
However the studies’ conclusion – that residue risks arise even with on-label glyphosate applications – fly in the face of Health Canada and its regulatory framework on MRLs. A premise of the Pest Management Regulatory Agency (PMRA) of Health Canada is that residues will not exceed MRLs, provided the spray directions on labels are followed.
The PMRA defines an MRL as the highest amount of residue legally allowed on foods when a pesticide is used according to label directions, and considers an exceedance of an MRL to be the result of not following the label. (The labels require spraying at less than 30% moisture content of the seed, which is when the seeds are more mature and accepting less pesticide. For barley, this is the “hard dough” stage.)
This premise of PMRA is clearly wrong. The research report shows an MRL exceedance can occur even when labels are followed.
The first report suggests factors that can cause exceedances in real farming conditions, such as the nonuniform level of crop maturity in the field.
“In addition, many uncontrollable environmental events (wind, heat, rain) may affect the uniform and accurate rate of glyphosate application and consequently the level of glyphosate residue on the grain. This increases the risk of negative quality and residue effects of preharvest glyphosate applications”.
Reports support legal case of Safe Food Matters
The studies also provide clear support for the arguments made by Safe Food Matters (SFM) in its notice of objection (NoO) to the 2017 re-registration of glyphosate. In the NoO, SFM objected that PMRA had not looked at the health risk arising with preharvest use, and that labels don’t mitigate the risk.
SFM said labels don’t work because: some crops are indeterminate, which means the seeds will not mature all at the same time; the weather can affect moisture content; and the determination of moisture content by visual indicators – eg. “hard dough stage” – is a subjective determination and so subject to error. See: 2017 06 27 – Notice of Objection to PMRA re RVD2017-01.
PMRA provided a response to SFM in 2019 (See PMRA Response to Notice of Objection) which did not address the concern that labels don’t work. SFM sued on its NoO in 2019 in Federal Court Case T-277-19, lost, and won on appeal in 2022. The win meant the NoO was sent back to PMRA, who in a second Response to Objection did not grapple with the issues. Safe Food Matters sued for a second time (see Notice of Application (Amended) December 20, 2022), and case T-2292-22 is ongoing.
Preharvest use already outlawed in Europe
The conclusion of the reports align with the position of Europe on preharvest spraying of glyphosate. In its 2023 renewal of glyphosate, preharvest desiccation was outlawed, as was preharvest use on agricultural crops for weed control within 60 days of harvest. See: Europe to ban Pre-harvest Glyphosate Use on Crops – so should Canada.
Based on the reports, preharvest use must be banned
Preharvest use of glyphosate allows the pesticide to move right into the grains and seeds we eat. Assurances from PMRA that this is OK because labels must be followed are, because of these new reports, now empty assurances.
What this means is the Minister of Health can no longer have a reasonable certainty that no harm arises when glyphosate is used preharvest according to the labels. The legal conclusion is that because this “no harm” standard cannot be met, the approval for preharvest use must be rescinded.
The labels can no longer save glyphosate.
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