Herbage production and tiller density in five related grasses, their hybrids and mixtures

Abstract

S U M M A R YFour grass species, three hybrids and three mixtures were grown in field swards near Aberystwyth. All swards were amply supplied with nutrients and were cut at 5-week intervals during the year of sowing (1989) and during the following 4 years. The order of the grasses in rate of establishment was: Westerwolds ryegrass > Italian ryegrass (Lolium multiflorum) > Italian ryegrass x perennial ryegrass, Italian ryegrass x meadow fescue, perennial ryegrass (Lolium perenne) > perennial ryegrass x meadow fescue, meadow fescue (Festuca pratensis) > tall fescue (Festuca arundinaceci). During the sowing year as a whole, Italian ryegrass was the highest yielding grass, followed by Westerwolds ryegrass. During the remaining period (1990-93), as a whole, the highest yields were obtained from perennial ryegrass sown alone or in a mixture with tall fescue. Tall fescue sown alone was one of the lowest yielding grasses in the year of sowing, but developed to be the highest yielding in 1992 and 1993. Westerwolds ryegrass persisted least well, although some plants did survive until 1992. Italian ryegrass persisted better than Westerwolds and Italian ryegrass x meadow fescue persisted better than Italian ryegrass. Hybrid ryegrass and perennial ryegrass x meadow fescue persisted satisfactorily but with fewer tillers/m 2 than perennial ryegrass or tall fescue. The yield of tall fescue in March was as high as that of Italian ryegrass in 1990 and 1991 and higher than that of any of the other grasses in 1992 and 1993; the tiller density of tall fescue was particularly high in March. The yield of mixtures (Italian ryegrass with perennial ryegrass, Italian ryegrass with tall fescue and perennial ryegrass with tall fescue) was, on average, 2-5 % more than the mean of the component species when sown alone. When grown with ryegrass, tall fescue was not prominent initially but its proportion in the sward gradually increased. I N T R O D U C T I O Nw ' t * 1 l^e mtr°d uction of new cultivars, old studies become out-dated and new studies are required. The selection of grass species, hybrids and mixturesIn the present study we have included four species, for sowing should be based on as much information three hybrids and three mixtures. Some differences as possible about their herbage production potential, between these grasses in morphology and development rate of establishment and persistence. However, most have already been reported (Gao & Wilman 1994; of the emphasis on grass evaluation, as in the work of Wilman et al. 1994). The present paper considers the National Institute of Agricultural Botany (1994) differences in herbage production and tiller density, in England and Wales, has been on comparisons of cultivars within species, rather than on comparisons M A T E R I A L S AND M E T H O D S of species, hybrids and mixtures.Within the Lolium-Festuca complex, which pro-Eleven sward types were studied: five stands were vides most of the species and cultivars normally sown sown as pure stands of a single species, namely in Britain,...

The silage yield potential of hybrid ryegrass over a 5‐year period in Northern Ireland relative to other ryegrasses and timothy

“…However, despite being significantly more open, the yields of the hybrid and the Italian ryegrass swards did not collapse with time. This may be the primary cause of the difference between the results of Wilman and Gao (1996) and the present study, in which the Italian and hybrid ryegrasses both out‐yielded perennial ryegrass and timothy for the 5‐year duration of each experiment.…”

“…Most notably, this ranking order was maintained throughout the investigation, and there was no evidence of hybrid ryegrass swards declining in yield more rapidly than perennial ryegrass over the 5 years. Wilman and Gao (1996) reported a different response to sward ageing. Italian ryegrass (cv.…”

“…The yield of hybrid ryegrass was significantly higher than Italian ryegrass only in the fourth harvest year. Wilman and Gao (1996) suggested that the decline in yield of Italian ryegrass was as a result of differences in persistency. After the 1992 harvest there were fewer plants in the Italian ryegrass sward but the tiller density in perennial ryegrass plots had increased.…”

“…However, a short‐term sward sown for silage can contain species that are not as persistent, but are capable of producing higher yields than perennial ryegrass, such as Italian ryegrass ( L. multiflorum Lam.). The difference in persistency of these two ryegrasses was demonstrated by Wilman and Gao (1996) in which the tiller density of Italian ryegrass (cv. Multimo) decreased from 2750 in the year of sowing to 1600 tillers m –2 2 years later, compared with perennial ryegrass (cv.…”

A new procedure for evaluating lucerne genotypes for semi‐arid land in west China

“…Plant density of lucerne varied markedly with time (Willman & Gao 1996), and is known to be an important factor in population persistence (Askarian et al 1995), because competition between plants affects their ability to acquire water and nutrients. In this trial, persistence of each cultivar was defined by observing the decline in density with time.…”