Chemical solutions are finite. Weeds are dynamic and evolving.
Growers have various approaches and systems for managing weeds in their fields. In areas of glyphosate resistance, agronomists regularly encourage producers to utilize pre-emerge herbicides in their weed control program. In more severe cases, some growers opt for a mechanical means of control such as tillage. Narrower row spacing and cover crops are additional tools that have demonstrated measurable improvements in weed control. In a chemical weed control program, good stewardship means using multiple different modes of action throughout the season. There is no “silver bullet” pesticide or weed control program.
Dicamba has been around for over 50 years but has recently come back into the spotlight due to the development of new seed traits and associated release and use of in-crop Dicamba products.
An inherent challenge of Dicamba technology is volatility. Off-target movement due to volatilization can occur up to 48 hours after application, especially in hot weather or with temperature inversions that favor the suspension of droplets.
Many times, the most basic of all tools available to manage drift is overlooked – the spray nozzle. Enhancements in modern rate control technology work in tandem with an operator’s general knowledge of herbicide application to provide added layers of risk management. By defining the nozzle being used and establishing a droplet profile, the operator will know at a glance what size droplet is being applied at all times. Using a simple visual cue, fine droplets can be avoided. “Fines” are highly susceptible to drift, are at a higher risk of not containing adequate amounts of active ingredient, and easily become suspended in the atmosphere.
Herbicide resistance is the main impetus for recent seed trait development. I’m reminded of a quote from the movie Jurassic Park: “Life finds a way.” Repeated exposure to the same chemistry is a recipe for resistance. Use of lower than labeled rates is a sure way to create a problem in your fields. The new trait technology is a great tool but it must be protected by farmers who use it in the correct way. By utilizing a rate controller on your sprayer that maintains accuracy at all times, the likelihood of under application can be minimized. Gen 2 DirectCommand does this by using pressure based control in lower flow situations where a flow meter’s accuracy may diminish. I’ve seen the effects of under application at low speeds in many fields as I travel, and I bet you have too. Where do we typically see the weeds? Edges of the field. Think about what is happening as the sprayer enters and exits the edge of the field.
Read about all the ways technology can overcome today’s application challenges here.