Effect of Herbicide Suppression of Tall Fescue Sod in Winter with Metsulfuron or Glyphosate on White Clover Establishment.

Tall fescue forms a dense sod which makes establishment of small-seeded legumes difficult without sod suppression or sod disturbance. Suppression of fescue sod with herbicide in winter may improve establishment of white clover without excessive sod damage. Two field studies were established in tall fescue pastures in north-central Arkansas. White clover was no- till planted in fescue sod at 2 lbs/acre on February 20, 2007 and 2008. In the first trial, metsulfuron herbicide was applied at the rate of 0 and 0.33 oz/acre immediately after planting.  In the second trial, glyphosate herbicide was applied after planting at 0, 4, 6, 8, 12, and 16 oz/acre. Clover stand was assessed by counting the number of squares containing clover in a 5x5 wire frame at monthly intervals during the growing season.

Treatment with metsulfuron suppressed the tall fescue, but also reduced clover establishment. Visual observation indicated an increase in orchardgrass and Kentucky bluegrass and a suppression of fescue in treated plots.  The average percent clover stand for the treated plots was 2.5% and was 60.9% for the untreated control. Glyphosate suppressed the tall fescue, but did not increase clover establishment compared to the untreated control. Clover percentage ranged from 76% to 84%. Results indicate that herbicide treatment in late winter did not improve establishment of white clover in tall fescue sod.