University of California Riverside County, Calif., Farm Advisor Mike Rethwisch in Blythe, Calif., is finding that the gibberellic acid inhibitor Apogee from BASF Corp. produces more alfalfa leaves and less stem from high-yielding desert summer alfalfa cuttings.

Rethwisch has been experimenting with the product for about four years and this year is conducting large scale trials that are getting considerable interest from local hay growers who envision getting six diary-quality hay cuttings per year vs. only three, according to Craig Pauly, BASF sales representative in Yuma, Ariz., who reported on Rethwisch’s work at a recent BASF field day at the company’s research farm in Dinuba, Calif.

The payback on an investment of $20 per acre for the PGR could be $40 per ton when dairy quality is bringing $120 per ton and lesser quality hay $70 per ton.

Yield reduced

There is a trade off, however. It reduces yield, as much as 15 percent. "We had a reduction of 300 pounds per acre," said Rethwisch. However that yield loss comes when alfalfa hay yields are the highest of the year, softening the yield loss. "We can produce two tons of hay per acre per cutting in the summer," he said.

The yield tradeoff is not dissuading producers Rethwisch said. Producers are very interested in his research because it could mean the difference between trucking hay to market at baling time or letting it sit in the turn-row awaiting a bargain-hunting buyer.

Dairy quality hay will always sell in California’s growing dairy industry, and Rethwisch is trying to produce that through six cuttings instead of three.

"Hay production is very high during the summer months in the desert because May, June and July are the longest days of the year," he said. "Hay grows so fast because it is also so hot then. This rapid growth means longer stems.

"What we are doing is shortening the internodes and the energy that would go to stems goes to producing more leaves," he said.

Rates used

Rethwisch said he has used rates of from .0625 active ingredient per acre to .25 pounds a.i. "These rates may be a little higher than what a commercial grower would use, but we wanted to test these high rates," he said, adding he said rates of .10 to .125 pounds a.i. per acre would likely be used commercially, applied by air. The higher the rate, the longer the PGR’s effect on stem elongation, added the farm advisor.

If BASF registers the product, it would likely carry a brand name other than Apogee for alfalfa use and likely would be cheaper than the apple product.

If dairy operators could get dairy quality hay through the summer in California and Arizona, it could preclude them from buying alfalfa from Utah, Nevada, Idaho and other northern tier states.

On the other hand, these states could derive the bigger benefit from a PGR like Apogee. "The farther you go north, the longer the days are and therefore the greater benefit from a PGR," he added.

The product makes an ideal management tool because it affects only one cutting. This would allow producers to evaluate the cost of the product against current hay market prices and make an economic decision whether to invest in it or to forego the cost.

"This is the first year we have tested the product on a commercial hay field, and we are pleased with the results," said Rethwisch, whose trials are on Desert Security Farms near Blythe, Calif.

"Tests came back from the May Memorial Day cutting showing the product produced premium hay vs. the check where quality was good," he said. He is awaiting lab results from the June cutting.