Genetic marker technology is allowing seed companies to roll out new insect-resistant traits much faster than in the past. The newest insect-control products for 2013 will focus on the soybean cyst nematode (SCN) and aphids. Next-generation insect traits in the pipeline will control other insects such as stink bugs and armyworms.
“We’ve certainly had SCN as a top priority in our genetics program, because it’s the biggest per-acre yield robber for soybeans out there,” says Scott Erickson, Syngenta soybean genetics manager. “Syngenta is doing a lot of work with molecular markers in our field tests that show us which new varieties have high tolerance for SCN, and we are now able to quickly incorporate those genetics into our breeding program for better-yielding, higher-resistance varieties.”
Syngenta is introducing 23 new soybean varieties for 2013, and most will be SCN resistant. “These 23 new varieties represent one-third of our soybean lineup and one-third of our volume of seed for next year,” Erickson says. “We are also beefing up our breeding efforts in northern climates. For example, we will have six different SCN products available in Group I maturities.”
Erickson says that Syngenta has used the leading source of resistance, PI 88788, but also has introduced a second source, Peking resistance, into its lines.
The predominant genetic source of SCN resistance in most soybean varieties is PI 88788, reports Loren Giesler, University of Nebraska–Lincoln Extension plant pathologist. However, he cautions that in many areas in the United States, SCN are adapting to PI 88788 resistant varieties and overcoming the resistance.
“Yet, in most fields, this resistance source is still effective,” he adds. “Even in fields with a moderate percentage adapted to PI 88788, the resistance in this source will still help.”
Monsanto will have a total of 77 new SCN-resistant soybean varieties available to growers for 2013, all with PI 88788 source resistance, according to Bruce Schnicker, Monsanto global plant health. “Nearly all current Genuity Roundup Ready 2 Yield soybean varieties contain resistance to the primary race [Race 3] of soybean cyst nematode, a pest that causes an estimated yield loss of 100 to 200 million bushels per year in the United States,” he says. “Monsanto breeders continue to develop new soybean varieties that will contain traits targeting additional SCN races, with planned introductions in the next several years.”
Other soybean insect-control products from Monsanto include Genuity Roundup Ready 2 Yield aphid-tolerant varieties for the upper Midwest, which were launched in 2011, says Nick Weber, Monsanto public affairs. “This product was developed via breeding, using the Rag1 gene discovered by the University of Illinois. In phase 2 of our R&D pipeline, we have the second-generation of aphid-tolerant soybeans, which will be a stack of multiple-resistant genes.”
A second-generation insect-protection soybean product, which will provide multiple modes of action and include protection against armyworms, is in phase 2 of Monsanto’s research and development pipeline, Weber adds. “This product can offer improved durability of insect control, and additional modes of action,” he says.
For 2013, DuPont Pioneer is offering 42 new SCN varieties available to growers from late Group 0 to mid-late Group V maturities, says Don Schafer, DuPont Pioneer senior soybean marketing manager.
“SCN populations continue to build and move further north, east, west and south,” he says. “Each year we’re striving to provide more resistant varieties in every maturity zone. Not too long ago, South Dakota used to be non-cyst geography, but we’re now bringing SCN-resistant products to that marketplace as well, because SCN continue to move west into South Dakota. We’re even in the testing process for introducing a late Group 00 maturity for the northern Red River Valley in northern Minnesota and into Manitoba and northern Ontario.”
DuPont Pioneer offers three different sources of SCN resistance: PI 88788, Peking, and PI 437654 (the source from which Hartwig was derived), according to Schafer. “Recently, we have been significantly increasing commercially available varieties with Peking resistance and now have more varieties with this source of resistance than any of our competitors,” he says.
“By expanding our sources of resistance, we are trying to stay ahead of SCN race shifts,” Schafer continues. “Recently, we’ve been finding places in central Illinois, near Peoria, where PI 88788 resistance isn’t holding up. One of our new products for 2013 is a mid- to early-Group III variety (93Y25) with SCN resistance from Peking that will be helpful to combat the races that are prevalent in these areas.”
DuPont Pioneer is now moving Peking into both late Group II and Group III maturities, Schafer notes. “A number of our highest-performing products in the early maturity groups are now varieties with Peking resistant sources,” he says. “With new gene-marking technology, we’ve learned how to bring a product along faster without the yield penalties that we once had in the past.
“A majority of our soybean product, over 75% of the volume we sell, is an SCN-resistant variety,” Schafer says. “For 2013, we will also have a new soybean variety (95Y60) available with PI 437654 resistance for mid-Group V maturity zones and we have pre-commercial products in research testing for Group IV maturity zones.”
DuPont Pioneer is also very close to introducing aphid-resistant soybean varieties. “We are working on three different resistant sources (Rag1, Rag 2, Rag 3) and have pre-commercial products in testing,” Schafer says.
Bt traits for soybeans are also in the pipeline. “Bt soybean traits are being developed to control Lepidoptera insects and Hemiptera insects,” Schafer adds. “Our initial target marketplace for them is in Brazil and Argentina, with the southern United States as the secondary target market.”
Most of Mycogen Seeds’ soybean varieties are now SCN resistant, according to John Kalthoff, Mycogen. “We have only a handful that are not,” he adds. For 2012, the company is introducing 10 new SCN-resistant varieties out of 15 new soybean lines. A Dow AgroSciences’ company, Mycogen introduced 20 new SCN-resistant varieties out of 31 new soybean lines for 2012.
“Almost anything we have in Mid Group I or later maturities are SCN resistant,” says Kalthoff. “In 2013, we’re introducing a lot of new early-maturity soybeans.”