Many growers have been sacrificing yield in their glyphosate-tolerant corn because they wait too late to make their weed control applications, according to research completed by DuPont in 2007.

“In Ontario, about two thirds of glyphosate-tolerant corn growers waited to spray until all weeds had emerged. In Quebec, over 96 per cent of growers did not apply a herbicide until all weeds had emerged,” explained Steve Babulal, corn and soybean product manager for DuPont. “In general, they were spraying too late to optimize yields because they were not controlling weeds before the critical three to four leaf stage of the crop.” 

For those who used glyphosate alone for weed control in glyphosate-tolerant corn, the issue came down to timing. Since there was no residual in glyphosate, many growers wanted to wait as long as they could before they sprayed in an attempt to avoid the need for a second application. 

However, independent studies by university and government researchers show that growers needed to control weeds by the time the glyphosate-tolerant corn was at the three to four leaf stage to help maximize yield. In 2006 Hamill, AAFC and Sikkema, Ridgetown College, reported that in the presence of weeds, there was a large yield penalty if weed control was delayed past the three-leaf stage of glyphosate-tolerant corn.¹ 

DuPont™ Galaxy™ herbicide tank-mix - Grower Comparisons Show Improved Yields over Glyphosate alone*

“In grower-applied, side-by-side comparisons, fields treated with DuPont™ Galaxy™ yielded an average of 11 bushels more per acre than fields treated with glyphosate alone,*” Babulal said. 

The trials were conducted in 2007, with Galaxy™ herbicide tank-mix applications made at the two-leaf to four-leaf stage of the crop – the optimal application timing for the product.   These were compared against one application of glyphosate made at or after the six-leaf stage – when research shows most growers typically apply their glyphosate.  

Guy Noiseux of St. Jean Baptiste, Rouville Québec was one of the growers who participated in the Galaxy™ herbicide tank-mix trials. “Normally I would wait until all my weeds are up before applying glyphosate," observed Noiseux.  "Galaxy™ allowed me to spray earlier, and get the weeds before they could reduce my yield.  I was happy to see that my Galaxy™ fields out-performed the fields where I had used just glyphosate alone by more than nine bushels per acre!”

Babulal explained, “The residual weed control offered by  Galaxy™ allowed growers to spray earlier and still control later-emerging weeds. This helped keep the crop free from weed competition during the Critical Weed Free Period (CWFP). The bottom line was improved yield retention.”

DuPont launched Galaxy™ herbicide tank-mix in 2007.   It provides residual weed control and multiple modes of action in the early to mid-post emergence spray window.  

DuPont is a science-based products and services company. Founded in 1802, DuPont puts science to work by creating sustainable solutions essential to a better, safer, healthier life for people everywhere. Operating in more than 70 countries, DuPont offers a wide range of innovative products and services for markets including agriculture and food, building and construction, communications, and transportation. 

^{*2007 DuPont initiated grower applied side by side comparisons.}

^{1Hamil, AAFC & Sikkema, Ridgetown College}

^{With any crop protection product, read and follow label directions.}

^{The DuPont Oval Logo, DuPont™, The miracles of science™ and Galaxy™ are registered trademarks or trademarks of E. I. du Pont de Nemours and Company.}

^{DuPont Canada is a licensee. Member of CropLife Canada.}

For more information, please contact:

Marie Fournier
Marketing Communications Specialist
DuPont Canada
Phone: 905-821-5816

Karen Sample
McCormick Company
Phone: 519-475-4769