SEED YIELD RESPONSE OF THREE FORAGE GRASSES TO THINNING

Abstract

Orchard grass, timothy, and bromegrass were grown for seed production in 35.5- and 71.0-cm row widths, containing plants in a solid or in a 35.5-cm thinned row arrangement. Seed yield, head numbers, head length, seed per head, and seed weight data were collected for 3–5 crop years. Orchard grass produced its highest yield of seed from the 71.0-cm thinned rows. Yield differences were present for the first 3 years only. Yield components were affected to a larger extent by row width than by thinning. However, with timothy, row widths did not influence yield and components some years. The production methods affected the bromegrass seed crop in the 1st crop year but had no influence by the 3rd year. Although some relations were established between seed yield and the components with the species studied, none appeared to clarify the physiological relations involved.