Like most cow-calf operators, Chuck Crutcher looks for ways to make the most of his forages. Last spring, he applied a new plant growth regulator on two of his pastures to promote faster early season growth. The results, he says, look promising.
“I got nearly twice the amount of dry matter from the treated field in the first part of April – an additional 4,500 lbs. With last summer turning into a drought year, that extra tonnage early in the season meant I had to buy less forage later on.”
Working with his Extension agent, Doug Shepherd, the Rineyville, KY, grazier treated 10 acres of alfalfa and orchardgrass, along with a 6-acre pasture of red clover and fescue with RyzUp SmartGrass.
The main ingredient in the new product is a naturally occurring plant hormone called gibberellic acid. According to the manufacturer, Valent BioSciences, it enhances early spring and late-fall growth in cool-season pastures.
The liquid formulation’s recommended application rate is 0.3-1 oz in 10-20 gallons of water per acre. Shepherd coordinated several grower field trials last spring in Hardin County, just south of Louisville. The growth regulator was custom-applied with a surfactant on fields, including Crutcher’s, at the 0.3-oz rate in 15 gallons of water per acre on March 19.
“The manufacturer recommends that RyzUp SmartGrass be applied when daily high temperatures are between 40° and 60° in either spring or fall,” says Shepherd.
Good stands and top fertility are needed to get the most from the product, says Crutcher. “You can’t expect to get great yield results from a marginal field. My fields treated with RyzUp SmartGrass were well-established stands that get regular fertilizer applications at university-recommended rates.”
Soil tests taken after harvest showed Crutcher’s treated field of alfalfa and orchardgrass used an additional 105 ppm of potassium (K) and 13 ppm of phosphorus (P) for the added growth. The treated red clover-fescue field used an additional 47 ppm of K and 8 ppm of P compared to that of an untreated field, notes Shepherd.
Small-scale field tests conducted at Penn State and Michigan State University (MSU) showed that a well-timed application of the product could increase forage yield by nearly 1,000 lbs/acre.
“The faster growth from a well-timed spring application could allow a pasture to be grazed 10-14 days earlier,” says Richard Leep, MSU Extension forage specialist. “But a pasture needs to be greening up and showing early signs of growth before you apply the product in order to get maximum benefit from it.”
In field trials, Leep compared four plots of pure orchardgrass – one control plot with no applications, one where only the plant growth regulator was applied, a third where only 40 units of N were applied and a fourth where the growth regulator and 40 units of N were applied.
“The application of RyzUp SmartGrass increased dry matter yield the equivalent to applying 40 units of N per acre,” he says.
Within six weeks of the early April application, the plot getting the plant growth regulator and the 40 units of N produced twice the yield of the control plot, notes Leep.
Leep’s study and the one at Penn State also measured crude protein and fiber, and saw only minor differences between treated and untreated grasses. “There was a slight decrease in crude protein and a small increase in fiber content of the forages we harvested from the plots treated with RyzUp
SmartGrass. But it wasn’t really significant,” he says.
Crutcher says he will definitely try the product again in the spring, and possibly in fall, if moisture levels are sufficient then.
“We saw the biggest dry matter increase in red clover and fescue. I would like to try it on a pure fescue stand, because I think that would produce the biggest return.”
At a cost of $7/acre when applied at the 0.3-oz rate, RyzUp SmartGrass should prove profitable on the right fields, adds Shepherd. For more information, visit