SOD-SEEDING BIRDSFOOT TREFOIL IN ESTABLISHED ORCHARDGRASS WITH OVERALL OR BANDED HERBICIDES

Birdsfoot trefoil (Lotus corniculatus L. ’Viking’) was seeded directly into a predominantly orchardgrass (Dactylis glomerata L.) sward following overall or banded applications of paraquat (1,1′-dimethyl-4, 4′-bipyridinium ion, as dichloride salt) or glyphosate [N-(phosphonomethyl)glycine, as isopropylamine salt] to determine the degree of sward control necessary for stand establishment without tillage. Effects of the herbicide treatments and the seeding on botanical composition and dry matter production were determined by a vertical intercept technique and by hand separations of harvests into botanical components. Trefoil establishment was proportional to the degree of sward control during the seeding year. Little trefoil was established by direct seeding without herbicides. The banded herbicide treatments were less effective than overall herbicide applications for trefoil establishment. Trefoil yield obtained following overall application of paraquat was approximately 65% of that obtained following overall glyphosate treatment.Key words: Dactylis glomerata, glyphosate, Lotus corniculatus, herbicide, no-tillage, paraquat