4th-gen bent: Attack of the stress fighters

LEBANON, Ore. - While work on genetically modified turf that can withstand herbicide use continues, there are several new conventionally bred creeping bentgrasses that will hit the market beginning this fall.

When turfgrass breeders set their sights on the next generation of creeping bentgrass, improving stress resistance was top of mind. Now there are three “fourth-generation” bentgrasses approaching the market featuring dollar spot resistance, heat tolerance and competitiveness against Poa annua.

According to Dr. Virginia Lehman, who developed L-93 creeping bentgrass, the new advancements may not be as dramatic but they are definitely significant.

“When Crenshaw was introduced, it enabled the consistent and broader use of bentgrass much farther south than ever before,” she said. “Today, the Southern use of bentgrass is assumed, not really debated. So the changes with any new bentgrass will be more subtle than with the dramatic switch from bermudagrass to Crenshaw or L-93.”

Lehman’s fourth-generation bentgrass effort will be brought to the market this fall by Links Seed under the LS-44 name.

“LS-44 will improve the stability performance of the greens and fairways, especially during the summer stress months,” said Lehman. “The summer performance will rise to the average higher quality usually maintained during the cooler months.

“The goals with LS-44 were to have improved stress resistance, a higher density without having the level of maintenance required for the As and Gs and disease resistance to brown patch and dollar spot,” she added.

When it came to developing a fourth-generation bentgrass, Turf Merchants Inc. (TMI) also looked to dollar spot resistance. The firm’s new bentgrass, Benchmark, will be available in 2004.

“We spent multiple years infecting plots and letting it run its course,” said TMI’s Steve Tubbs. “We selected the surviving clones and interpollenated them and infected them again. After several years, you end up with a variety that has near total dollar spot resistance.”

While Tubbs said future improvements in bentgrass will be more gradual, he is excited about Benchmark.

“It is a big breakthrough because of the environmental benefits of cutting back on chemical use,” he said. “Chemical companies should be buying seed companies now because we have a naturally dollar spot resistant turf, which will eliminate the need for those expensive chemicals.”

FIGHTING PVP AND POA ANNUA

On the bentgrass front, Jacklin Seed has been busy fighting for L-93’s Plant Variety Protection (PVP) while also working on the development of a fourth- generation bentgrass.

In early June, the United States Department of Agriculture’s Plant Variety Protection (PVP) commissioners decided to abandon protection of Jacklin’s L-93 creeping bentgrass.

“It is all a procedural legal issue that had to do with missing a deadline,” said Joel Barker, vice president and general manager for Simplot Turf & Horticulture. “It was the snafu of trying to buy something out of [the ABT] bankruptcy. We are considering further legal action to reinstate the application.”

Despite the ruling, Barker said, Jacklin retains the right to be the sole provider of certified L-93. “We need to make the point to distributors and superintendents to look for that blue tag,” he said.

Jacklin is also moving ahead with its new bentgrasses with the T1 and T2 series. A limited amount of seed is currently available as samples and seed will be available in 2004.

“We have sent out 3,000 pounds to get it introduced,” said Jacklin Seed research director Dr. Doug Brede. “The results that have come back have been extraordinary. Courses have subjected turf mowed at 1/10 of an inch to a divot test and have seen it fill right back in. It also has good competitiveness against Poa. You can abuse this turf and it bounces right back.”

CONVENTIONAL BREEDING VS. GENETICALLY MODIFIED TURF

While there is no doubt that genetically modified turfgrass will have the ability to change the face of the marketplace, conventional breeding will still play a significant role.

“The fact that when a problem arises and breeders go to work and breed in natural resistance in a matter of years is a pretty powerful message,” said TMI’s Tubbs.

Dr. William Meyer, head of the turfgrass breeding program at Rutgers University, agrees.

“There is still tremendous potential in conventional breeding,” he said. “If you compare turf breeding to corn breeding, we are in the infancy. They have the corn genome and we are starting to do that on bentgrass here. But there are still many opportunities in conventional methodologies.”