‘Cougar’ Kentucky Bluegrass Seed Production as Affected by Clipping to Stimulate Grazing 1

This study was conducted to determine the seed production responses of ‘Cougar’ Kentucky bluegrass ( Poa pratensis L.) to clipping at different times from early fall through late panicle branching at the onset of panicle elevation in the spring. Treatments were repeated for 3 years. The bluegrass was grown in rows, sprinkler irrigated, and fertilized as needed to maintain high levels of N, P, and K. Some clipping treatments increased seed yields; none decreased yields. Late fall and the onset of panicle development were the two best times for defoliation. Clipping in late fall markedly increased panicle numbers, decreased weight of seed/panicle, and increased seed yield. Clipping at the onset of panicle development in the spring slightly increased panicle numbers and seed yields without materially reducing the weight of seed/panicle. Two clippings produced significantly more Iorage than most single clippings, but not more than one clipping in late fall, apparently because little vegetative growth occurred between late fall and late panicle branching. Defoliation in late fall or early spring prior to secondary panicle branching offers the possibility not only of providing forage but of increasing subsequent seed yield through increased panicle production.