Establishment of Perennial Forages I. Subsequent Yields 1

The effects of five establishment methods on subsequent yields of six perennial forages were studied in two similar experiments. The methods of establishment used were a check with natural weed growth, two oat companions ( Avena sativa L. and A. byzantina L.) with contrasting canopies, hand weeding until mid‐July, and planting in mid‐August after a crop of oats was removed. Percentage of incident solar radiation was significantly greater under the oat companion with the less‐dense canopy when weed competition was light. Conversely, with severe weed competition, significantly less radiation was observed under the same companion because of greater weed growth. Yields of forages established with the two companions did not differ significantly the year following seeding. Alfalfa ( Medicago sativa L .) stands were less sensitive to interspecies competition than were crownvetch ( Coronilla varia L.) and birdsfoot trefoil ( Lotus corniculatus L.) stands. Inverse relationships existed between interspecies competition and tiller densities of smooth bromegrass ( Bromus inermis Leyss), reed canarygrass ( Phalaris arundinacea L.), and orchardgrass ( Dactylis glomerata L.). With adequate moisture and fertility, treatments resulting in low tiller densities showed a rapid recovery by the second harvest of the year after seeding. Summer sowing of alfalfa and the three grass species in dry summers resulted in greater yields from three harvests taken the following year than were obtained when these species were planted in mid‐April, weeded until mid‐July, and then harvested twice in the seeding year. During the first 2 years, increased production resulting from weeding normally would not have compensated for yield of the companion crop. Harvesting both the companion crop and undersown species .for forage at an early stage would very likely result in greatest total production.