Potential Impact of Group 2 (ALS Inhibitor) Herbicide Residue on Winter Wheat Survival - Early Reconnaissance
Hammermeister, E.H. K.J. Greer and C.D. Ball . 2012. Soils and Crops
Abstract
Next to the coinciding harvest of spring crops, the biggest challenge winter wheat seeding faces
is finding early matured and harvested crop land for seeding at the optimum window from late
August to early September. Pulse stubble provides an opportunity to get winter wheat seeded in a
timely basis. Growing winter wheat on pulse stubble is commonly discouraged due to the very
limited residue and potential for snow trap. As overwinter success is connected to snow cover
and subsequent insulation against cold temperatures. We propose another challenge that may be
limiting success on pulse stubble. The repeated use ALS inhibiting (Group 2) herbicides and
soil residual that can inhibit root growth, nutrient uptake and subsequent fall seedling
establishment. A reconnaissance study was conducted on two locations, each with pulse stubble
but with differing Group 2 herbicide residue. Soil temperature monitoring showed that of the
three winter wheat cultivars examined, all should have easily survived the winter of 2010-11.
Significant impact on stand survival and yield was observed on the soil having Group 2 residues.
A cultivar interaction was also noted. Further investigation would facilitate identifying potential
crop nutrition management techniques to overcome agronomic challenges of successfully
growing winter wheat on pulse stubble. Investigation of winter wheat cultivar tolerance to ALS
inhibiting herbicide residues would also be of value
Key Words
Winter wheat agronomy, Crop rotation, ALS inhibitor soil residue, Winter Cereal Survival Model, PRS™ Technology
