Plant growth regulator gets green light in U.S.

Western Canadian wheat growers interested in maximizing yields and reducing crop lodging could soon have another tool at their disposal.

Last month, the United States Environmental Protection Agency announced that it has established a maximum residue limit (MRL) for chlormequat chloride, the active ingredient in plant growth regulator products sold under the brand name Manipulator.

Manipulator, marketed by EngageAgro, had already been cleared for use in Canada and in most countries that import Canadian wheat.

However, the lack of an MRL in the United States represented a major impediment to EngageAgro’s marketing efforts in North America.

With an American MRL in place, the product can now be used in Canada and the United States without fear of market disruption.

The next challenge for growers, however, will be sourcing product.

Tom Tregunno, EngageAgro’s North American product manager, told the Western Producer via email last week that the company is sold out of Manipulator.

Production, distribution and marketing efforts in North America will be ramped up in 2018 and ample supplies should be available to Canadian and American wheat growers beginning next year.

EngageAgro representatives were unavailable for further comment.

Plant growth regulators are a relatively new product in the Canadian marketplace but they’ve been used in Europe for decades.

Manipulator now has MRLs established in all major wheat-producing and importing nations.

Here in Canada, independent researchers who have tested the product say it has potential in dryland and irrigated production systems.

When applied at the proper stage of plant growth, Manipulator reduces plant height, resulting in crops with shorter, stronger straw that are less prone to lodging.

Operator stress, machine workload and fuel consumption at harvest are also reduced based on lower straw volumes.

Efficacy of the product varies depending on the type of wheat is being grown, the timing of application and the amount of actual nitrogen being applied to the crop.

Promotional literature provided by EngageAgro suggests that Manipulator resulted in increased yields 93 percent of the time and reduced straw height 94 percent of the time, regardless of nitrogen application rates.

For optimal results, the product should be applied at the one– to two-node stage, or growth stage 31 on the Zadoks scale.

The recommended application rate is 1.8 litres per hectare

At that rate, product costs are expected to come in at about $15 per acre, not including applications costs.

Chris Holzapfel, research manager of the Indian Head Agricultural Research Foundation (IHARF) at Indian Head, Sask., said his experience with Manipulator suggests that the product has a place on modern grain farms that are pushing yield.

In a recent presentation, Holzapfel said Manipulator performed consistently well under Saskatchewan field conditions, resulting in reduced plant height in nearly all trials and higher wheat yields in most cases

A copy of Holzapfel’s January 2018 presentation can be viewed online here.

“It showed really consistent benefits here, particularly on the trials that I’ve looked after at this location,” said Holzapfel.

“There were a few cases where there was no significant yield benefit, just a bit of height reduction or some lodging benefits, but for the most part, I’ve been surprised at the consistency of the yields benefits that we’ve been getting from the product here at Indian Head.”

Holzapfel and his team of researchers have been testing manipulator at Indian Head since 2012.

Similar trials have also been conducted at other Saskatchewan research locations near Scott, Melfort and Yorkton.

At Indian Head, applications of Manipulator showed yield benefits of seven to eight percent over untreated checks, even in dry years when lodging risks were relatively low.

In wetter years, where the risk of lodging was increased, the yield benefits were greater.

“I think the return on investment is probably there,” Holzapfel said.

“They (EngageAgro) are looking at (a product cost of) about $15 per acre so you’d need a few extra bushels to cover that but we’ve gotten that very consistently in our trials.”

“I guess the idea of an extra $15 an acre and an extra pass with the sprayer wouldn’t appeal to all growers but I think there’s certainly an appetite among some growers, based on discussions I’ve had.”

Major grain-handling companies in Western Canada are expected to remove Manipulator from the list of restricted crop inputs that grain producers are forbidden to use.

The Keep It Clean – Cereals program will also remove comments or references to chlormequat chloride from all print and digital materials, said Cereals Canada president Cam Dahl.

Dahl said the announcement that chlormequat chloride has an established MRL in the United States is good news.

“This is a potentially valuable tool that has seen limited use in Canada because of the lack of approval in the U.S. and the market risk that this entailed,” Dahl said.

“That barrier to use has been removed.”

Dahl commended EngageAgro on taking a cautious approach to marketing Manipulator in Canada, even though the product had been cleared for use on Canadian farms before the EPA announcement.

“This is an example of responsible product introduction that reflects potential costs and benefits to all parts of the value chain.”


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