Syngenta highlights new aphid management system

Date:08-06-2009

Syngenta Seeds will highlight its new aphid management system for soybeans at its Farmfest seed plots.

The aphid management system will be available for purchase by farmers for the 2010 growing season, said Luke Christensen, a Syngenta agronomist. A price hasnt been established.

The new varieties are in several plots across the state, including NK, Garst and Golden Harvest plots at Farmfest.

The Syngenta aphid management system includes three components: A Cruiser Maxx seed treatment, an aphid resistant trait in the seed and money back to clean up with an application of Warrior insecticide if the population exceeds threshold levels.
University of Minnesota Extension soybean specialist Seth Naeve said the aphid management system may be a fit for some acres, but its not a cure-all and it wont replace scouting. He suggested farmers interested in adopting the technology try it on limited acreage.

The worst thing would be for farmers to plant the varieties and think they dont have to scout, Naeve said.

Likewise, Dave Ragsdale, professor and head of the University of Minnesota Department of Entomology, said there is definitely farmer interest in this type of product, but he urged caution.

The new varieties with the aphid resistant traits should reduce peak aphid density and yield loss, but they are not immune to aphids, he said.

There are two identified sources of genetic resistance, RAG1 and RAG2, and aphids have already shown an ability to overcome RAG1, Ragsdale said.

He said seed treatments are a waste of money for aphid protection because they are only persistent to the third- or fourth-leaf stage, well before aphid pressure is at its peak.
However, Christensen said soybeans treated with Cruiser Maxx were showing lower levels of aphids at this point in the season.

Christensen said the aphid resistant varieties planted in the Farmfest plots were completely clean when he scouted on July 29, while aphids were present on the other varieties.

Soybean aphid numbers are on the rise across Minnesota, according to the July 31 issue of the Minnesota Pest Report, and some fields were expected to soon meet the 250 aphid per plant with 80 percent of plants infected threshold.

Christensen said spraying was under way in parts of southwest Minnesota last week, with planes in the air and ground rigs at work as well. He looked at some fields and found 300 to 400 aphids per plant in some and five to 10 per plant in others.

Its important for farmers to scout a couple times a week during this period, Christensen said. Soybean aphid repopulating peaks when temperatures are 75 to 80 degrees.

Farmers could see significant yield losses if they arent scouting and treating if needed.

The aphid-resistant varieties look like other soybeans grown in Minnesota, but the soybean aphid doesnt reproduce as well on these varieties, Christensen said. The aphid resistance trait is not a biotech trait, it has been bred into varieties sold in Minnesota from a Group 8 soybean grown in the southern United States, he said.