Most read





Plant growth regulators (PGRs) may be the next big wave of crop management tools helping farmers to increase cereal crop yields and profitability, but the products that have been widely used in Europe and other parts of the world for decades still have to earn their stripes in Canada.

It’s not that they don’t work to reduce and strengthen crop stature and therefore help to reduce lodging. It’s a question of whether the growing conditions here are suitable, whether crop management is up to the rigours of the specific timing for application, and whether regulations and attitudes need to change to allow farmers better access to the products.

Bayer CropScience has had Ethrel on the market for some time, and BASF has a product called Cycocel Extra. Both are more widely used in the horticultural industry, although Ethrel is also registered for use in cereals and Cycocel Extra for use on winter wheat. Because of their narrow window of application and other limitations, neither has been widely promoted to western grain growers. In fact, Ethrel is not readily available across Western Canada because timing of application is so critical that the company requires producers to sign a liability waiver before they can access the product.

Syngenta, which already markets cereal crop PGRs in the U.S. (a product called Palisade) and Europe (Moddus), is conducting research on a similar trinexapac-ethyl-based product in Canada.

In the meantime, Engage Agro, based in Guelph, ON, may have the most exciting news on the PGR front. It hopes to have a product, Manipulator, registered for use on Canadian cereal crops in mid-2014 and available for producers in 2015. Based on a different active ingredient than other products, Manipulator is said to be more user friendly. It is effective at a wider temperature range, has a much wider window of application and can effectively be used in tank mixes with many herbicides.



The value of plant growth regulators needs to be kept in perspective, said Sheri Strydhorst, a research scientist with Alberta Agriculture and Rural Development in Barrhead. While they can play an important role, they won’t have a fit in all growing areas, and they do have a very specific purpose.

“There may be a bit of confusion over what plant growth regulators do,” said Strydhorst, who is conducting research and field trials with PGRs. “The goal of a PGR is not to increase yield. The goal is to increase harvestability of the crop—to help crops stand better. But in doing that, if crops don’t lodge they are likely able to fill better, which can improve yield. And if a crop isn’t plastered to the ground, then, again, farmers are able to harvest more grain. But the main purpose of the PGR applied to the crop is to prevent cells from elongating and to lower the rate of cell division so you have a shorter-stature crop with stronger stems.”

Strydhorst said PGRs have been used extensively in parts of the world where cereals are grown under relatively high moisture conditions. Figures from the U.K., for example, show that between 80 and 90 per cent of winter wheat, winter barley and winter oat crops are produced with one to two applications of a PGR each year.

In Canada, Strydhorst sees PGRs having the best fit in irrigation districts and in higher-moisture growing areas, generally regarded as the black soil zone. However, in recent years, as many farmers in Western Canada know, higher moisture conditions have prevailed in many areas outside the black soil zone.

“With higher moisture conditions, more farmers are seeing the potential to increase crop yields by using higher rates of nitrogen and a wider range of crop-protection products,” she said. “But one of the limitations as producers push for higher yields is the risk of crop lodging. So with PGRs we have a potential tool that may allow for higher yields and improved standability.”

Strydhorst’s research with both Ethrel and Cycocel Extra PGRs did not produce dramatic results in 2013. It was only one year, and growing conditions vary, but she said she saw only a slight improvement in lodging and a crop height reduction of about seven centimetres (two to three inches). However, she is planning to expand the research to 15 sites in 2014, from southern Alberta’s irrigation district to the Peace River region.

“Growing conditions can certainly play a factor, and the other thing to remember about PGRs is that some varieties are more responsive than others, so their effectiveness can depend on the year and the variety.”



That was the general observation of central Alberta farmer Dallas Dau in 2013. He was involved in a PGR research trial organized by his local crop consultant. Dau said a research plot on his Three Hills-area farm didn’t produce any dazzling results showing the effectiveness of PGRs on preventing cereal crop lodging, but he said he is hopeful that over the next two or three years it will emerge as another useful tool in increasing crop yields and overall efficiency.

Dau said the biggest problem in 2013 with products applied to reduce lodging in both wheat and barley was probably that it was just too good a growing year.

“The products have very specific timing and they were probably applied on the later end of the window,” he said, “but it was a year with such ideal growing conditions, I think the crops just blew right through the products—just kept growing.

“Our wheat and barley were both just growing gangbusters, and even after we applied the products they didn’t slow down a bit.”

The 40-acre field had plots of wheat and barley seeded with varying rates of fertilizer from a standard check level to double the fertility rates.

“Lodging can be a concern so we have to watch how much fertilizer we apply,” said Dau. “On these plots, I think the wheat did stand a bit better but it wasn’t a huge difference. I think because it was such a good growing season, it might have been a bad year to try this. But it was only one year and I’m hoping we do it again for at least two or three more years to get a better idea of how it works. It will be an excellent tool if it works.”



While field research is important, Elston Solberg, president of Agri-Trend Agrology and a longtime crop consultant, said he believes the broader use of PGRs should be a “no-brainer.” He said that the industry needs to do a better job of education to ensure the proper product is applied at the proper rate and at the proper timing, but that there is no doubt PGRs can be a valuable tool in helping farmers increase crop production efficiency by getting higher-yielding crops to stand better.

Solberg was involved in research work with PGRs in Canada nearly 30 years ago, “and at that time these products had already been in use in Europe for about 20 years.”

Even back in the late-1980s, the use of PGRs in trials showed a reduction in lodging, which translated into easier combining, improved crop quality and, in many cases, higher yields.

But because timing and management of product use is so critical, some mistakes were made and interest in the products never took off.

“Fast-forward to 2013 and now the world has had another 30 years’ experience with the products,” said Solberg. “These products have proven themselves in high-producing, high-yielding environments, so I think we should be able to figure it out here.

“The other thing we keep hearing is that over the next 36 years we need to be producing 70 per cent more crop on each acre of land we have now, which means higher rates of fertilizer to produce higher yields, which predisposes us to a higher risk of lodging—which, to me, means that if PGRs aren’t already a no-brainer, they soon will be.”

Solberg said PGRs won’t be effective on every acre of cereal crop in Western Canada, but they will have a fit in higher-producing environments and on farms able to apply a higher level of management.

“It isn’t just about the timing of the product, it is about the whole crop production system,” said Solberg. “They need to be used in a system that uses the proper (higher) seeding rate, proper fertility, and good management of crop-protection products. PGRs can be a useful tool in a system where all these management factors are integrated.”



Another longtime central Alberta farmer and crop consultant, Steve Larocque of Beyond Agronomy said that, after four years of field research and some trial and error, he is convinced PGRs can be an effective tool in helping “malt and feed barley growers attain higher yields in our semi-arid climate.”

Larocque said the increased risk of lodging is the limiting factor in achieving consistently high barley yields.

“In our area, applying nitrogen rates above 100 pounds per acre usually resulted in lodged barley and would void any gains we made through intensive agronomy,” he said. If he applied 120 pounds of nitrogen, his barley crop would go flat.

Obtaining the products for research purposes, Laroque worked mainly with Ethrel and Cycocel Extra. He said he found Ethrel to be the most effective on wheat and barley. He also did some trials with Manipulator on wheat. Manipulator is expected to be registered in 2014 and available for commercial use in 2015.

Timing and temperature were indeed critical, he said, adding he also used a lower rate of Ethrel than the 400 millilitres per acre recommended for crops grown under irrigation. He said he had the most success using 250 millilitres per acre. That rate reduced lodging in barley, but didn’t shorten the height too much. If the crop is shortened too much, a combination of rainfall, sunlight and open canopy can encourage late tillering, which he didn’t want.

With Champion barley, for example, Larocque said he found he could apply up to 180 pounds of nitrogen and, with the properly timed PGR, the crop remained standing. Crop height was about 10 inches shorter compared to untreated crop.

“Overall, I am very encouraged by what PGRs can offer farmers with the proper management,” he said. “I believe they will take us to the next level by giving farmers a tool to manage their lodging risk. On average, I think we’ll be able to apply another 20 to 30 pounds of nitrogen and realize between 10 to 20 bushels per acre higher yields.”

His main caution, however, is that “the timing of Ethrel is absolutely critical for the PGR to be effective and not cause crop injury.

“Apply Ethrel at late flag leaf or just prior to awn emergence. You want the main stem and the tillers to be in full flag leaf stage. Application before flag can kill off tillers, while application at awn emergence will reduce kernel numbers.”

While he said he likes the price point of the product—ranging from $4 to $6 per acre—he said management is critical and the challenge for producers with a lot of acres is to use the product at the proper time on every acre.

“If you’re thinking about using a PGR like Ethrel, understand the risks, proceed with caution, but realize it could be a valuable tool in your quest for higher barley yields,” said Larocque.



Tom Tregunno, Engage Agro product manager for Manipulator, said the flexibility of the product will help to attract more farmers to the concept of using a plant growth regulator.

“It’s not something all farmers will use, but it will probably have the best fit in the irrigation areas and within the black soil zone, or in areas where growing conditions are good even on a year-to-year basis,” Tregunno said.

“It is amazing to see how this product works in Europe. Of course, much of the U.K. has perfect growing conditions for wheat. They can apply up to 200 pounds of nitrogen and, even with lower seeding rates, achieve yields well over 100 bushels per acre. And they may be applying multiple applications of a PGR during the growing season. We’ll not likely be doing that here, but it is an example of how it is used.”

Tregunno said because Manipulator can be used within a wider temperature range and a wider timing range, in many cases it can be applied by itself or tank-mixed with herbicides, appealing to producers looking to optimize yields.

With Manipulator expected to enter the marketplace in 2015, the company has already done considerable research with the product across Western Canada.

“We are planning more extensive field trials again in 2014, not only to demonstrate the product to producers, but also to further support our registration,”

he said. “Our main focus in research trials this year will be to increase fertilizer rates to further test the effectiveness of the product. So our trials this year will be looking at rates ranging from 10 to 25 to 50 and even up to a 100 per cent increase in fertilizer rates, with different varieties, to see where the limit is.”

Tregunno said that while the main purpose of Manipulator is to reduce the risk of lodging under higher fertility rates, in many trials they have seen that the product itself appeared to improve yield without added fertility.

When Manipulator was applied with no fertility over the regular rates, wheat trials conducted at AAFC Indian Head Research Farm produced up to a seven per cent yield increase between 70 and 80 per cent of the time, said Tregunno.

“It is primarily intended to reduce lodging but the thinking is that, because plants are shorter and putting fewer nutrients into longer stems, they are putting more resources into seed development.”

Since varieties can respond differently to the PGR, Tregunno said the reduction in plant height can range from five to 20 per cent, depending on the variety.

“We see it as a tool benefiting farmers looking to make use of good growing conditions, who are prepared to supply the inputs, provided they can keep the crop standing,” he said. “And it is a product that offers flexibility. If you have improved growing conditions this year, then increase your fertilizer rates to take advantage of those conditions and apply Manipulator to keep the crop harvestable and capture that increased yield.”

Tregunno said the initial registration will be for all classes of wheat, including winter wheat, and Engage Agro may look at adding barley to the registration down the road.



Be the first to comment on this article

Leave a Reply

Go to TOP