Using glyphosate before harvest can make for an effective perennial weed control strategy, but to protect crop quality (and international market access), producers should be leery of timing.
“I want to remind producers that if you are going in with pre-harvest glyphosate, it is not a desiccant – it is a pre-harvest glyphosate,” says Jeremy Boychyn, agronomy research extension specialist with Alberta Wheat and Barley Commissions. “So you want to go into the field, and you want to make sure you are at 30 per cent moisture in that kernel.”
According to Boychyn, testing moisture levels can be done in the field, but you must select the greenest areas.
“There are two things you need to do [to moisture test]. You want to check to make sure that the peduncle — so that’s the area right underneath the head at the top of the stem — is dried down. You don’t want any green in that material,” Boychyn says. “If that’s dried down, and it looks like there isn’t any green at all, then what you do is break that head, hand thresh, and do that thumbnail test, where you are pushing your thumbnail into the kernel, and if it idents into the kernel — but doesn’t mush the kernel up or change the shape of it, and holds that indent — then you are at 30 per cent.”
With the added pressure of a multi-stage wheat crops, Boychyn emphasizes the importance of keeping an eye on any late tillering if you are considering using pre-harvest glyphosate.
“Those late tillers coming in, depending what their timing is, they are now the least advanced part of your crop. So if you are thinking of going through with the glyphosate, it is those parts of the crop that you need to assess, and make sure they are at that 30 per cent moisture.”
To learn more about considerations you should keep in mind headed into the harvest season, check out this RealAg Radio clip of Shaun Haney and Jeremy Boychyn: