Response of Biennial and Perennial Weeds to Selected Herbicides and Prepackaged Herbicide Combinations in Grass Pastures and Hay Fields

Abstract

Field trials were established in orchardgrass and tall fescue grass pastures and hay fields during 2000 and 2001 to evaluate wild carrot, broadleaf plantain, buckhorn plantain, bladder campion, and yellow crownbeard response to a variety of herbicides and prepackaged herbicide combinations. Picloram plus 2,4-D at 0.23 plus 0.84 kg/ha and higher, triclopyr plus clopyralid at 0.96 plus 0.32 kg/ha and higher, and 2,4-D plus triclopyr at 2.20 plus 1.12 kg/ha provided greater than 84% wild carrot, broadleaf plantain, and buckhorn plantain control at 4 mo after treatment (MAT) in both years. Metsulfuron, picloram plus 2,4-D at 0.30 plus 1.12 kg/ha, and 2,4-D plus triclopyr at 2.20 plus 1.12 kg/ha provided from 56 to 61% control of bladder campion 4 MAT, which was the highest bladder campion control observed in these trials. Greater than 80% yellow crownbeard control was achieved during both years with picloram plus 2,4-D at 0.15 plus 0.56 kg/ha and higher and with triclopyr plus clopyralid at 0.96 plus 0.32 kg/ha and higher. Results from these experiments reveal that good broad-spectrum control of many biennial and perennial broadleaf weeds can be achieved with higher rates of the picloram plus 2,4-D and triclopyr plus clopyralid prepackaged combinations.