Senescence and death of herbage during periods of regrowth in ryegrass and red and white clover, and the effect of applied nitrogen.
Abstract
Above-ground yield and the production of senescent and dead tissue were measured in perennial and Italian ryegrasses, white and red clover and in mixtures of these species during 2 regrowth periods in late summer/early autumn. During the first 3 weeks of regrowth, applied N at 56 kg/ha approximately doubled yield of ryegrass without increasing the production of senescent and dead tissue. During the later stages of regrowth in ryegrass and white clover, production of new tissue was approximately counterbalanced by senescence and death. Red clover grew vigorously during late summer to produce a tall high-yield crop which contained a relatively low proportion of senescent and dead tissue. Losses due to decomposition and other causes were extremely low in red clover during this period. During early autumn the growth of red clover was more similar to that of white clover.