Each site of damage is a clue to take into consideration when trying to properly diagnose herbicide damage.
Diagnose herbicide damage, or prevent it in the first place
Sherlock Holmes once quipped, "There is nothing like first-hand evidence." Farmers must strike a similar attitude if they want to properly diagnose any mystery herbicide damage, says Isaac Ferrie, who presented on the topic at Corn College Advanced this past summer. That means farmers must make two important observations before they reach any sound conclusions.
First, look at the whole field, Ferrie says. The pattern of damage distribution can reveal a lot about what caused it. For example, damages limited to field borders and edges are often drift-related. If the entire field is affected, misapplication could be the culprit.
Second, look at where the damage is occurring on the plant. Is it on leaves? Roots? Old growth? New growth?
"For example, if the damage has translocated into new parts of the plant, you’re dealing with a systemic herbicide," Ferrie says. "If it’s only in the old growth, it’s a contact herbicide."
Specific plant damage will further delineate what mode of action to suspect. Farmers should also have the following information handy to make the best diagnosis: variety/traits planted as well as herbicides sprayed on the field during the past and present seasons and in adjacent fields.
"It’s important to take good notes, not just for your safety but also for your neighbor’s safety," Ferrie says.
Industry doubles down. As crops tolerant to 2,4-D and dicamba near commercial launch, the makers of those traits and herbicides are developing low-drift formulations. More importantly, they are ramping up education efforts to eliminate more application mishaps before they happen.
BASF, who has developed various formulations of dicamba for the past 49 years, is releasing its low volatility formulation, Engenia. The company has also put more than 3,000 farmers through its On Target Application Academy, which focuses on proper sprayer calibration, pressure speed and more.
The hands-on training has been helpful to farmers and retail applicators, says Luke Bozeman, BASF herbicide technical market manager. BASF is also incentivizing the purchase of certain nozzles and sprayer equipment.
"BASF recognizes that’s money well spent," Bozeman says.
Dow AgroSciences is in a similar position. The makers of 2,4-D have developed a low-drift glyphosate plus 2,4-D choline formulation called Enlist Duo. Before a single gallon of the herbicide is sold, Dow has spent an equal amount of time and energy developing "Enlist Ahead," a program aimed at tools, training and management recommendations, says David Hillger, Enlist field specialist with the company.
"We’ve been focused on education," he says. "We want to preserve this technology for the long term."
- Mid-February 2014