By Mitchell Japp, Provincial Specialist, Cereal Crops, and Clark Brenzil, Provincial Specialist, Weed Control
August 31, 2016
You know the expression “Use it or lose it”? It can refer to many things, from keeping up practice at a skill or sport, to knowledge gained from a recent course or field day, to getting to harvest when the crop is ready before it rains again.
In some examples, though, it needs to slightly modified to “Use it right or lose it”. This is well presented in pre-harvest applications of glyphosate.
Glyphosate on oats
While we are anxiously waiting for new research on the impact of pre-harvest glyphosate on oat milling quality, we know one oat miller has stopped purchasing oats treated with pre-harvest glyphosate. They did their own internal research and determined that milling quality was unacceptably lower when oats had been treated with pre-harvest glyphosate.
In theory, glyphosate applied at the end of hard dough stage (less than 30 per cent moisture) when the crop is fully mature should not affect milling quality or cause shrinkage. At that stage, the grain has senesced from the plant and no longer receives sugars, other nutrients or glyphosate from the plant.
However, if the glyphosate was applied too early, glyphosate could accumulate in the grain and prevent it from reaching its full weight and maturity, which may have an impact on milling quality. This led to one miller’s decision to no longer buy any oats treated with pre-harvest glyphosate, regardless of whether it was applied at the correct stage or not.
Glyphosate on durum
Italy is the top export market for Canadian durum, averaging nearly 700,000 tonnes annually since 2006 (and more recently exceeding 1 million tonnes). There are some brands of pasta that are exclusively Canadian, which probably doesn’t sit well with their producers. Now Italy has introduced restrictions on their producers’ use of glyphosate, which has a major Italian producer organization pointing a finger specifically at Canada and suggesting that Canadian producers should be subject to the same rules as Italian producers.
Among the changes, the key one is that it prohibits pre-harvest use for the sole purpose of optimizing the harvest or threshing. In reality, this is no different from the current label in Canada. Glyphosate is intended for pre-harvest perennial weed control. However, this change in Italy has their farmers asking for imported grain, specifically Canadian imported grain, to be subject to the same treatment.
We can speculate that some growers applied pre-harvest glyphosate to their oats too early (using it off-label in an attempt to “even the crop out” prior to harvest, rather than for weed control). As a result of not being used correctly, glyphosate is no longer a tool for oats in one miller’s marketplace.
Will durum be next? While it is unlikely the Italian government will make rash, rapid changes to allowable residues in imported grain, they may be scrutinizing Canadian shipments more closely. If any Canadian shipments exceed tolerances for glyphosate, it will be costly. The question is – will it be costly for one ship, lead to the loss of glyphosate as a pre-harvest management tool or lead to the loss of Canada’s largest durum market? Every Canadian durum producer can influence this outcome by applying glyphosate correctly. Otherwise, every Canadian durum producer could be the worse for it.