Submitted to: International Journal of Agronomy
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/29/2009
Publication Date: 8/31/2009
Citation: Nandula, V.K., Poston, D.H., Reddy, K.N., Whiting, K. 2009. Response of Soybean to Halosulfuron Herbicide. International Journal of Agronomy. 2009(754510):1-7. Interpretive Summary: Drift injury to soybean from halosulfuron when applied to neighboring rice fields is a concern among soybean farmers. Sulfonylurea-tolerant (ST) soybean varieties have enhanced tolerance for sulfonylurea herbicides and might provide an option of mitigating injury from halosulfuron drift. Scientists from Delta Research and Extension Center, Mississippi State University; USDA-ARS, Southern Weed Science Research Unit; and DeltaPine Land Company have conducted experiments to test sensitivity of selected soybean varieties to halosulfuron. The varieties with no ST-trait were sensitive to halosulfuron and severe halosulfuron injury in two non-ST varieties resulted in yield loss. Halosulfuron did not have a significant effect on yield of ST varieties. These results indicate that commercial soybean varieties with ST trait alone or stacked with Roundup Ready trait can be planted in areas around rice fields and could tolerate halosulfuron drift from applications made in rice fields as drift rates are only a fraction of label use rate.
Technical Abstract: Recently, halosulfuron injury in soybean through off-target movement of halosulfuron when applied to rice fields has been reported. Sulfonylurea-tolerant (ST) soybean varieties have enhanced tolerance for sulfonylurea herbicides and might provide an option of mitigating injury to soybean from halosulfuron drift. Experiments were conducted to evaluate the effect of halosulfuron on growth and yield of selected soybean varieties with ST trait alone and stacked with glyphosate resistance trait. Soybean plants were treated with halosulfuron at 0, 0.0043, 0.0087, 0.017, 0.034, and 0.069 kg ai/ha rate at the V3 growth stage in the greenhouse and at 0.034 kg/ha rate (label use rate in rice) in the field studies. All soybean varieties containing the ST trait exhibited some halosulfuron injury, but survived the halosulfuron application in the greenhouse. In a field studies, a single POST application of halosulfuron at 0.034 kg/ha to soybean at three-trifoliolate leaf stage or at full bloom stage resulted in halosulfuron injury to certain extent regardless of ST trait. Halosulfuron did not have a significant effect on yield of ST varieties compared to their respective nontreated controls. Severe halosulfuron injury in two non-ST varieties resulted in yield loss.