What is in this article?:
- Widely Variable Soybean Cyst Nematode Makes On-Farm Testing Key
- One tough customer
- Unpredictable response to weather
- Life after SCN
- New seed treatment against SCN coming in 2014
- University research
The widespread drought made 2012 a banner year for SCN in Iowa. “In 25 years I’ve never seen as much reproduction as we did last year,” says Greg Tylka, Iowa State University (ISU) Extension nematologist and plant pathologist. “We don’t understand exactly why SCN seems to thrive when it’s dry, but we also know that nematodes grow best in the greenhouse under dry conditions. “
Conversely, the 2013 growing season began in Iowa with record rains, delaying soybean planting. “But by June 2,” Tylka says, “SCN females were reported on soybean roots in sandy soils just 26 days after planting. In a normal spring, we expect to see female nematodes 40 days after planting.
Very often, the only visible sign of soybean cyst nematode is an egg sac on soybean roots.
New seed treatment against SCN coming in 2014
Syngenta hopes to introduce a novel seed treatment for SCN control in 2014. Clariva Complete Beans nematicide/insecticide/fungicide is a combo treatment that adds a new nematicide to the broad-spectrum seed treatment of CruiserMaxx Beans with Vibrance insecticide/fungicide, says Palle Pedersen, seed care technology manager with Syngenta.
“Clariva Complete Beans includes the active ingredient Pasteuria nishizawae, a naturally occurring SCN predator,” Pedersen says. “It provides a direct mode of action because it must infect the nematodes to reproduce. P. nishizawae penetrates nematode juveniles to lay their eggs. This reduces SCN feeding and reproduction, and ultimately kills the pest.
“Spores of the parasite remain in the root zone throughout the season to offer continued activity against SCN,” Pedersen says.
“This has the potential to revolutionize soybean production,” says Seth Naeve, University of Minnesota Soybean Extension specialist. “We don’t know where this will go, but this naturally occurring bacterial that attacks SCN could be huge if it really works. SCN is our No. 1 pest; its impact has been completely underestimated. Breeders have had difficulty building resistance into germplasm, and we don’t have chemical controls,” Naeve says.
During three years of replicated yield trials, Syngenta found that Clariva improves yield by 3-5% on top of current SCN-control techniques and CruiserMaxx,” Pedersen says. “In addition to comprehensive pest protection, Clariva optimizes root health to deliver better plant emergence and stand, nutrient uptake and water usage, stress tolerance and overall soybean performance.
“The seed treatment does not replace resistance-management technology already in use,” Pedersen adds. “It complements current SCN-control tactics of planting non-host crops and SCN-resistant soybean varieties, and rotating varieties with different sources of resistance,” Pedersen says.