In-crop herbicide application season can be a busy time, and there are many factors to consider to make your herbicide application efficient.
Technical marketing specialist of herbicides with BASF, Andrew Reid, talks herbicide efficacy with RealAgriculture’s Kara Oosterhuis in this episode of Pulse School.
Before you jump in the sprayer there are a few questions to ask:
- what product am I using?
- what stage is the crop at?
- what water volume am I using?
- what weeds am I going after?
- what else can I put in the tank (and should I really)?
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In terms of water volumes, “the label is always your default” says Reid, but sometimes water volumes are provided in units western Canadian farmers don’t use, such as litres per hectare. Reid suggests to consult the tech sheets, visit the product website, or call in to the helpful company phone-lines to ask for the most accurate conversion. More water often means better efficacy, especially for in-crop herbicides.
Nozzle selection plays into herbicide efficacy and affects coverage. For a product like Viper, which has a contact herbicide in it, adequate coverage is important, says Reid. Ensure the right nozzle is matched with the right water volume to get good droplet size and you’ll have good weed control.
Poor growing conditions will also affect herbicide efficacy. Especially in pulses, in-crop products are primarily based on imidazolinone or ‘imi’ chemistries are reliant on the plant’s metabolism to be effective. “If it’s super hot or super cold outside you’re not as likely to see good efficacy and you’re also more likely to see injury on the crop itself,” says Reid. “If you have poor growing conditions, if you have cold nights, you can see a lot more injuries start to shop up, even though you’ve sprayed at the correct timing or staging.”
Lentils are very tolerant to ‘imi’ based chemistries. “Please don’t spray Viper on lentils,” warns Reed. Lentils are labelled up to the nine node stage, explaining that the first two scale nodes are not counted, only above-ground nodes. Peas have a bit tighter staging than lentils do, where application staging is from three to six aboveground nodes. Check peas first if you’re growing both pulse crops.
“The key is, to get out and take a look,” says Reid. “Timely scouting is absolutely essential.” Ten to 14 days after an application is sprayed, go out and check those fields to make sure that herbicide is working.
If a farmer is seeing escapes after spraying and the crop is already in flower, it’s too late for a rescue spray. Those escapes will have to wait until a pre-harvest pass. Then there is concern for pre-harvest products posing export marketability challenges for some crops.
One last piece of advice, double-check your tank mixes, Reid says. Supported tank-mix lists can be found at your local retailer or available from your local chemical sales representative.