With soybean aphid populations able to increase so rapidly, growers in turn need rapid awareness as populations approach the economic threshold for deciding if and when to spray an insecticide treatment. One way soybean growers can keep up with the latest localized information on this insect pest is by clicking on a new Web site - www.AphidAlert.com. The information for the site comes from university and USDA sources in each state.
Farmers can also sign up to receive free localized text alerts and information when aphids hit their area. The alerts will notify you as to what's going on within a 75 mile radius of where you farm. To get these free localized alerts, growers can text the word APHID along with their ZIP code to 46786 to receive the alerts when aphids infest their area. Standard text messaging rates apply.
"The Web site was created to give growers a one-stop shop for information on the background, scouting and treatment for aphids, says Steve Olson, insecticide product manager for Bayer Crop Science, sponsor of the site."Growers can also go on the site and sign up to receive a free alert via e-mail, voice alert or text message when aphid populations are on the rise in their area."
Warning when aphid infestations are near threshold
The alerts provide a warning when aphids are near the economic threshold level, which is a sign that it is a smart time to scout fields and consider the use of an insecticide application to protect soybean yields.
Although you can't predict what Mother Nature has in store for the 2009 growing season, you can protect your fields from sucking and chewing pests such as aphids, bean leaf beetles and Japanese beetles, says Olson.
It is imperative that you scout your fields or have them scouted regularly, at least once a week to determine if aphid populations are reaching the economic threshold. Check the upper two or three trifoliate leaves and stem for aphids first. Aphids are most likely to concentrate in the plant terminal early in the growing season. They move down into the lower part of the plant later on.
When scouting, you should also look for ants or lady beetles on the soybean plant. "They are good indicators of the presence of aphids," says Matt O'Neal, an Iowa State University Extension entomologist. "Lady beetles feed on aphids, while ants tend the aphids and 'milk' them for honeydew."
Timely application of insecticide can protect yields
Last year, Iowa grower Josh Joyce took the advice of his local crop consultant and applied an insecticide to his field when aphid pressure increased to the threshold of 250 aphids per plant. Joyce, who farms near Graettinger in northern Iowa, says switching to a different insecticide than he had used in previous years paid off in 2008.
"We've had high aphid pressure the past few years and I wanted to try a different product," he says. "In the past, I didn't like the late applications of insecticides with planes coming in or coming in late and applying an insecticide over a lot of soybeans. I was looking for an insecticide product that I could spray only once and it would control the aphids for the rest of the season."
How many times do you have to spray insecticide?
Joyce says he applied Leverage 2.7 insecticide last year and it knocked down the aphids. "We even saw residual activity that kept the aphid pressure down throughout the remainder of the growing season. The greatest benefit was we didn't have to reapply the insecticide. In previous years, we've had to come back and spray two or three insecticide applications in one season."
Leverage has two modes of action, both contact and in-plant, that provide rapid knockdown and residual protection from a broad spectrum of insects, including soybean aphids, bean leaf beetles, grasshoppers and Japanese beetles, says Olson. This insecticide offers other economic value in that it can be tankmixed with fungicides and herbicides, he says.
University researchers recommend applying an insecticide when the infestation reaches 250 aphids per plant on 80% of the plants scouted in the field. Growers who apply Leverage at that threshold should apply 3.8 fluid ounces of the product per acre, according to label recommendations.