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The trick is in the timing with plant growth regulators

FarmTech: The hormone reduces lodging and makes harvest a lot easier, 
but proper staging is a challenge

PGRs can be a valuable tool, but use with care, say Alberta producers 
Tom Eppinga (l) and Greg Stamp.
Reading Time: 3 minutes

Plant growth regulators can work, but use with caution.

If the conditions aren’t right, you could have a wreck, said participants in a plant growth regulators panel at FarmTech.

“If you’re going to use a plant growth regulator, focus it on situations where you are pushing yield limits,” said Emile deMilliano, manager of training with Crop Production Services. “Plant growth regulators should be used when lodging is an issue and where you are pushing yield potential.”

Plant growth regulators (PGRs) are growth hormones that naturally occur in the plant. If applied at the right time, they can stop cell division or stem elongation, reducing the height of the plant and making it easier to harvest.

But if applied at the wrong time, they can have serious effects on plant growth and yield. Manipulator can be applied at growth stage 12 to growth stage 37, while Etherel can be applied between growth stages 37 to 45.

PGRs, which are only registered for spring and winter wheat, can reduce plant height by as much as 40 per cent and lodging by up to 70 per cent when used properly. But types and varieties of wheat will respond differently. Growing conditions can also affect the way the products affect the plants.

“When you apply a PGR, you want optimum growing conditions to be occurring. That is really important,” said deMilliano.

Agronomists, growers, and researchers are just starting their work on PGRs and how they work in Western Canada. They’ve been used for years in Europe, but Europe has 200 growing days, while Canada has only 90 to 100 growing days, said Ryan Adams, manager of agronomic services with Crop Production Services.

Grower experience

Tom Eppinga of Triple T Farms near Bon Accord has experimented with PGRs on his farm and has found both positives and negatives.

The biggest pro is increased yield, along with increased standability, and reduced lodging and disease. He loved that he was able to harvest more bushels an hour, and not have to deal with as much straw the following year. Eppinga also saw a heavier bushel weight, which translates into more yield and better quality.

And using plant growth increased morale on his farm because the harvest was so much easier, he added.

On the other hand, if things are dry, PGRs do not offer any benefit, and managing the timing can be difficult. Eppinga said he also worries about consumer push-back to the use of the hormone, and many companies are not taking Manipulator-treated grain because the product isn’t registered in the States.

“You have to be really careful — every CPS and hard red has different characteristics that will change how it responds to the product,” said Eppinga. “You have to try this on every farm and see how your variety responds. It’s not for every farm and every area.

“It’s kind of a combination of high fertility, high seeding rate and sufficient timely rains that will give you that lodging problem. If all of those three things come together, then it’s a nice tool to pull out of your tool box. If the timing is perfect, hit it and your dream will come true.”

Greg Stamp of Stamp Seeds has also used PGRs on his family’s farm near Enchant. Stamp has used Manipulator, Etherel and a Syngenta product called Parlay that works well on perennial ryegrass seed production.

“Where I had a miss in the field, you could actually see that it was lodging quite a bit,” he said. “But we were high fertility in those fields.”

Stamp has also tried Grocel, a gibberellic acid that promotes plant growth. He sprayed it on winter wheat this fall to help the crop overwinter and grow faster. He saw a benefit from applying it to the winter wheat seed, as it allowed him to plant the winter wheat a little later, while allowing for faster growth in the fall.

There is no benefit from applying a growth regulator on shorter wheat varieties like Gateway, which is only knee-high.

Manipulator needs to be applied at the five- to six-leaf stage. Stamp used Manipulator on the majority of his cereal acres under irrigation and tank mixed it with herbicides. He used glyphosate and a pre-pass with his burn-down to delay broadleaf weeds in the crop and planted his crop early. He was able to wait until the five- or six-leaf stage before herbicide application, and applied the Manipulator and herbicide together. He then was able to manage his irrigation and spray again at fusarium timing.

“I didn’t have to go in at flag leaf, so that saved me on my irrigation management,” he said. “This saved us a pass this year, and was really nice.”

The Stamps have used Etherel for the past eight years, and have found that if the head is out a few inches from the top of the stem, the field needs to be sprayed that day or the day after.

“If only 10 per cent of the beards are poking out at the top, I would still spray, but if it’s more than 10 per cent, you’re too late,” he said.

In some varieties or growing conditions, the heads will first pop out the side of the stem, which can take some people by surprise when they are staging their application, he added.

About the author


Alexis Kienlen

Alexis Kienlen lives in Edmonton and has been writing for Alberta Farmer since 2008. Originally from Saskatoon, Alexis is also the author of two collections of poetry, a biography, and a novel called "Mad Cow."



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