Evaluation Soybean Cultivar for Potential Tolerance to Dicamba.

Evaluating Soybean Cultivar for Potential Tolerance to Dicamba

Kansas soybean research plots experienced accidental dicamba herbicide drift from an application on a nearby wheat field in Hays, Kansas in 2016. One cultivar, with no known dicamba tolerance reported, did not exhibit any visual symptoms of dicamba injury. This lead to the question of whether the unaffected soybean cultivar could have natural tolerance to dicamba. To test for natural tolerance to dicamba, a dose response will be performed on the unaffected soybean cultivar, along with known susceptible and resistant cultivars. The test will be replicated five times. Cultivars will be planted in individual pots and then plants sprayed 21 days after emergence with a 0, 1/4, 1/2 and 1X field rate of dicamba. The rates proposed will simulate the amount of herbicide that would be present in a drift scenario. One week after treatment, the plants will be visually evaluated for dicamba injury. If tolerance is observed in this cultivar, further testing will be done to characterize the mechanism and level of tolerance. This trait potentially could be utilized in soybean breeding programs to provide better protection against dicamba weed treatment in post-emergence applications.

Kansas soybean research plots experienced accidental dicamba herbicide drift from an application on a nearby wheat field in Hays, Kansas in 2016. One cultivar, with no known dicamba tolerance reported, did not exhibit any visual symptoms of dicamba injury. This lead to the question of whether the unaffected soybean cultivar could have natural tolerance to dicamba. To test for natural tolerance to dicamba, a dose response will be performed on the unaffected soybean cultivar, along with known susceptible and resistant cultivars. The test will be replicated five times. Cultivars will be planted in individual pots and then plants sprayed 21 days after emergence with a 0, 1/4, 1/2 and 1X field rate of dicamba. The rates proposed will simulate the amount of herbicide that would be present in a drift scenario. One week after treatment, the plants will be visually evaluated for dicamba injury. If tolerance is observed in this cultivar, further testing will be done to characterize the mechanism and level of tolerance. This trait potentially could be utilized in soybean breeding programs to provide better protection against dicamba weed treatment in post-emergence applications.