Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Plants, Soils, and Climate


John O. Evans


An integrated management approach for jointed goatgrass control was investigated at two farms in northern Utah using three tillage regimes and tree herbicides. The tillage regimes included no tillage, conservation tillage, and conventional tillage. Each regime was composed of different tillage practices common in the Intermountain West. A preemergence herbicide, clomazone, and two postergance herbicides, 2, 4-D and glyphosate, were investigated. Greenhouse studies were also conducted to investigate clomazone efficacy and depth of planting of winter wheat and jointed goatgrass.

Differential sensitivity to clomazone between jointed goatgrass and winter wheat did not occur in the greenhouse for the rates tested. A treatment of 0.11 kg ai ha-1 clomazone reduced wheat and jointed goatgrass fresh weights similarly by 49 and 63% respectively.

Jointed goatgrass did not germinate below 6.4 cm and emergence was initially reduced at the 2.5 cm soil depth. Winter wheat emergence was not lowered until the seed was planted 5.0 cm deep or deeper and continued to 8.9 cm deep.