Effect of Picloram on Production and Quality of Seed in Several Grasses

Abstract

Twelve field trials were conducted in western Oregon during 1963 to 1966 to evaluate the effect of 4-amino-3,5,6-trichloropicolinic acid (picloram) on the seed production and seed quality of eight grass species. Seed production of creeping bentgrass (Agrostics palustris Huds., vars. Penncross and Seaside), Colonial bentgrass (Agrostis tenuis Sibth., var. Highland), perennial ryegrass (Lolium perenne L., var. Linn), Italian ryegrass (Lolium multiflorum Lam., var. Gulf), and tall fescue (Festuca arundinacea Schreb., var. Alta) treated with picloram was not statistically different from the untreated check. Seed production of Colonial bentgrass (Agrostis tenuis Sibth., var. Astoria) was reduced by picloram at rates of 1.0 and 1.5 lb/A. Seed production of Kentucky bluegrass (Poa pratensis L., var. Newport) was not statistically different from the untreated check when picloram was applied in October but was significantly lower than the check following some March treatments. Seed production of orchardgrass (Dactylis glomerata L., var. Potomac) and creeping red fescue (Festuca rubra L., var. Pennlawn) was reduced by most picloram treatments made either in October or March. Germination of the creeping red fescue seed was significantly reduced when picloram was applied at 2 lb/A in March. None of the treatments affected seedling development.