Survey work conducted in 2012 by Stratus Agri-Marketing Inc. for Monsanto Canada shows the farmer practice of spraying off-label is becoming more common.
The Stratus research results - compiled from online surveys with over 1,700 farmers - confirm 45 percent of farmers sprayed above label rates, up eight percentage points from 2011. The survey findings also showed that 30 percent of farmers sprayed after the six-leaf stage, as well as spraying above label rates, up four percentage points from 2011 results.(1)
After reviewing all the information, Monsanto Canada's technology development team conducted field trials to test potential crop injury from spraying Genuity Roundup Ready canola off-label. The results provide valuable information for farmers about the negative impact this practice has on their yields.
"Over a two-year period and 53 data points, our research confirmed that farmers are losing 3 bu./acre or more in yield by spraying Genuity Roundup Ready canola above recommended rates or outside the application window,(2)" said David Kelner, canola technical lead with Monsanto Canada based in Winnipeg. "The symptoms of injury are very subtle and not easy to diagnose so most farmers probably don't even realize there is a significant financial impact because their crop doesn't show any obvious signs of injury."
Over the past several years, the retail price of glyphosate has dropped significantly. While most farmers will agree that's a good thing, the price decrease is actually making it more affordable for farmers to spray higher rates of glyphosate on their Genuity Roundup Ready canola in an attempt to enhance weed control on their farms.
The recommended label rate of a Roundup brand agricultural herbicide over-the-top of Genuity Roundup Ready canola is either two applications of 0.33 litres/acre or one application of 0.5 litres/acre applied at the zero-to-six-leaf stage.
Jesse Hamonic, canola trait marketing lead with Monsanto Canada, acknowledges that farmers encounter stressful weather conditions and tough-to-control weeds every year, making the decisions around spraying difficult. By sharing the Stratus survey results and the Monsanto field trial research, he's hoping to help farmers make better spraying decisions that will put more dollars in their pockets.
"Effective control of weeds is critical to producing a high-yielding crop so we understand that farmers want to do a good job of managing their weeds," said Hamonic. "But they may not fully appreciate how spraying too much, or spraying outside the application window, can have a detrimental impact on yield, and ultimately their bottom line. At today's market value, losing 3 bu./acre translates to a loss of roughly $40/acre or more due to crop injury caused by spraying off-label."
Hamonic added that Monsanto's objective in sharing these research results is to quantify that impact for farmers and encourage them to spray within label recommendations. "It really is the best way to ensure an ideal growing experience with the Genuity Roundup Ready canola system," he said.
Farmers can learn more about practical and effective weed management solutions at the Roundup Ready Weed Management Solutions website http://www.rrwms.ca/.
(1) Stratus agri-marketing inc. Post-glyphosate rates in RR canola, Western Canada, 2012
(2) Monsanto Canada TD Research Trials, 2011-12. N=53