New study eyes nematode damage in corn
A new university report released today left unclear the value in many cases of using nematicides in corn. In the Ohio Corn Performance Test, in which hybrids were evaluated for grain yield and other characteristics, seed companies submitted hybrids that included nematicide seed treatments.
The results from the 2011 Ohio Corn Performance Test locations found no visible evidence of nematode injury, according to Terry Niblack, an Ohio State University plant pathologist.
“The testing was done as nematodes are receiving more attention as a potential yield-limiting factor in corn,” the Ohio State Extension report said.
In all but one test location, the risk index for the different nematode populations was either non-existent or low.
“While it is unclear if Ohio corn growers will have a problem with nematodes, farmers, growers and researchers are taking a closer look at the issue to see if the tiny organisms negatively impact corn yields and if seed treatment nematicides are needed,” the Ohio report said.
HEAVY DAMAGE POSSIBLE
In a recent Successful Farming magazine article, How to Manage Corn Nematodes, researchers described the potential for the pests to inflict heavy yield damage in corn.
“In corn, nematode damage is frequently misdiagnosed,” said Glen Dappen, a biologist and nematode specialist for Nebraska Wesleyan University. Nematode damage can be manifested as stunted plants, often showing small ears and kernels later in the season.
“The ears will not fill out,” Dappen told Successful Farming. “It's just like the corn plant ran out of gas.”
A number of factors can be blamed for “the seeming sudden rise” in nematodes in corn: more conservation tillage; few carbamate and organophosphate insecticides; and more continuous corn.
Two new seed treatments have recently appeared on the market: Avicta Complete Corn from Syngenta and Poncho/Votivo from Bayer CropScience, says Tylka. Avicta Complete Corn contains a nematicide that kills nematodes. Poncho/Votivo contains a biological compound that forms a protective barrier across corn roots that helps halt nematodes from feeding on corn roots.