Mississippi researchers find rice seed treatments work
After testing scores of samples taken from rice fields across the state, Mississippi State University scientists found that seed treatments are effective in managing the crop’s most troublesome insect pests.
“In Mississippi, we’ve been evaluating seed treatments for about five years,” said Jeff Gore, entomologist with the Mississippi Agricultural and Forestry Experiment Station and MSU Extension Service. “Our research has shown that rice grown with a seed treatment typically yields from 8 to 12 bushels more per acre than untreated rice. The main reason for that yield increase is rice water weevil control.”
Gore said seed treatments are effective in both conventional rice varieties and hybrids.
“Although they do not provide 100 percent control of rice water weevil, seed treatments do provide significant benefits in rice,” he said. “Because control is not absolute, a foliar insecticide application may be necessary to maximize control in some situations.”
Insect management …
Gore works at the Delta Research and Extension Center in Stoneville. He said researchers take core samples about 4 inches in diameter and 8 inches deep from farms across the Delta, wash them and count the rice water weevil larvae.
“An infestation of one larva per core will result in about a 1 percent yield loss,” Gore said. “Typical infestations in the Delta range from 10 to 25 weevils per core in untreated fields, resulting in a 10 to 25 percent yield loss.”
Gore said that seed treatments provide other benefits to rice producers, too.
“Seed treatments provide good control against a whole complex of other rice pests,” he said. “Seed treatments help manage chinch bugs, grape colapsis, thrips and soil insects, such as wire worms and white grubs, and get the plants off to a good, healthy start.”
Performance under flood …
Seed treatments for row crops, such as corn, cotton or soybean, target early-season pests that are in the soil when the seed is planted. But rice seed treatments are different.
“We’re targeting primarily rice water weevils, and they only move into the field when producers establish the permanent flood about three to six weeks after planting,” Gore said. “So seed treatments for rice have to last longer than in other crops, because they are sitting in the field a lot longer.”
Gore said all of the seed treatments are water soluble, and water can have both positive and negative effects on seed treatments.