The first biotech trait with the primary benefit of improved yield will be introduced in the Mid-South this spring. Soybean varieties with Roundup Ready 2 Yield (RR2Y) technology, which were planted on about 1.5 million acres in the Midwest as part of a limited release in 2009, will be available in Monsanto-owned and regional company seed brands.

Monsanto says studies indicate a yield advantage of 3.6 bushels per acre for RR2Y varieties over first generation Roundup Ready technology under typical management, according to the results of a three-year testing period from 2007-09. Aaron Robinson, technology development manager responsible for soybean traits and agronomics for Monsanto, says varieties with the trait will offer the same crop tolerance and safety of Roundup Ready soybeans.

According to Tennessee Extension soybean specialist Angela McClure, in limited testing of RR2Y and comparison varieties in strip trials and a replicated test at a research center in west Tennessee in 2009, varieties with RR2Y did not show a definite yield advantage.

“The soybeans were planted in May and harvested on time in September and early October, and yields were good for all the varieties. We did not see yield increases for the RR2Y versus the Roundup Ready varieties in the comparison. It could be in another year where we have drier weather in August that the (RR2Y) varieties may separate out.

“The concern is that there is a higher cost for the technology, and there’s a seed treatment going on the seed. Farmers have to make the higher cost up with higher yields, and based on our experience, it’s a little too early to say that they will yield consistently higher.”

McClure hopes for a more extensive look at the technology in Tennessee’s public testing program in 2010. “They’ll be compared to a lot of other commercially available varieties, and we’ll have a lot more opportunities to figure out where they fit.”

Mississippi Extension soybean specialist Trey Koger said yield trials of early Group 4s with RR2Y technology in 2009 showed “some mixed results, basically due to late planting dates at some locations and damage at some locations. Where we got some consistent results, they did okay. They didn’t yield any better than any of the other early- to mid-Group 4s in the trial, but we don’t plant a lot of early Group 4s, and they were very early.”

Mississippi researchers did not have access to late-Group 4 RR2Y soybean varieties for testing in 2009.

Varieties with the RR2Y trait will be available in Group 3 and Group 4 maturities, according to Robinson, “and we’ll have a handful of Group 6s available. The Group 6s have good resistance to stem canker and southern root knot nematode. The Group 4s are probably the strongest-performing maturity groups in the portfolio.”

RR2Y soybeans were developed by gene mapping DNA regions in soybean that have a positive impact on yield. The RR2Y gene is situated into one of these DNA regions to provide higher yield potential. The increased yield potential is partly attributed to more beans-per-pod compared to first generation Roundup Ready technology, according to Monsanto.

The technology is part of Monsanto’s recent three-point commitment, which includes doubling yield in three of the company’s core crops — corn, soybeans and cotton — by 2030.

Robinson says the yield advantage for soybean varieties with RR2Y is still evolving and will improve as growers “are able to select varieties specifically for their environment, region and for their individual management practices.”

The technology doesn’t require a change in management practices for growers, according to Robinson. But he added that under an intense management regimen, the yield advantage for the technology can surpass an average expectation of 3.6 bushels, given proper growing conditions.

Robinson says plants with the trait “will have more vigorous growth, potentially a denser canopy, more mainstem nodes and a higher percentage of three-bean pods. It’s all about producing more seed per pod, or more pods per plant.”

The soybean RR2Y trait has received approval for export and domestic use. For more information on the trait go to genuity.com.

To see more on the performance of the RR2Y trait, go to Monsanto.com.

e-mail: erobinson@farmpress.com