Effects of Poa trivialis L. on growth of perennial ryegrass and white clover

摘要

Abstract Herbage yields from Poa trivialis-white clover, perennial ryegrasswhite clover, and P. trivialis-perennial ryegrass-white clover swards were measured under two cutting managements. 17.8–l5.1 cm (“long”) and 7.6–2.5 cm (“short”). Ryegrass-c1over swards out yielded P. trivialis-c1over swards by 13% per annum (1335 kg/ha dry herbage) and P. trivialis-ryegrass-c1over swards by 11% per annum (1125 kg/ha dry herbage). P. trivialis-clover swards out yielded ryegrass-c1over swards only in winter under long cutting. In limiting periods for herbage production, such as in winter and in summer, differences between swards were less than 6% kg/ha dry herbage. Seasonal contribution of P. trivialis to total herbage yields from the P. trivialis-ryegrass-clover swards was up to %. Interspecific competition in P. trivialis-ryegrass-clover swards was more between P. trivialis and ryegrass than between P. trivialis and clover, because the seasonal growth patterns of the grasses were more coincident than those of P. t...