Annual and hybrid ryegrass cultivars in New Zealand

Abstract

<jats:p>Results are presented for 16 National Forage Variety Trials of annual and short-term hybrid ryegrass cultivars conducted in Waikato, Taranaki, Manawatu, Canterbury and Southland. In all, 30 cultivars (17 named, 13 experimental) were included. Cultivar effects were significant in all seasons, and for the annual totals. Cultivar differences were greatest in summer. Spring production accounted for over 40% of annual totals and summer production less than 20%, but it was summer production that was more closely correlated with the individual cultivar annual total. Over all trials and cultivars, regrowth in the second autumn accounted for 11% of the total for 12 months beginning in the winter following sowing. Comparing North Island sites with Canterbury sites, there was some indication of cultivar × region interaction, particularly in summer. Patterns of interaction of cultivars with trials were examined, and indicated that some cultivars can be grouped as having similar responses. Repeated trials at the same site were sometimes but not always consistent in ranking cultivars. The results indicate that some cultivars do perform consistently better than others, for particular seasons or for annual totals, so that the trials are a reliable indicator of which new experimental cultivars should be released to the market. The results also indicate that several trials are necessary to determine the merit of a wellperforming cultivar. The error associated with the mean of cultivars present in only one or two trials is high (standard deviation approaching 20% of the mean in some seasons). This may, however, be sufficient to eliminate poorer experimental lines from further consideration. Keywords: Italian ryegrass, hybrid ryegrass, cultivars, Lolium × boucheanum, Lolium multiflorum, pasture agronomy</jats:p>

Genetic origins of perennial ryegrass (Lolium perenne) for New Zealand pastures

“…Advances in perennial ryegrass breeding within New Zealand have taken place on many fronts, including yield, seasonal growth, disease resistance, endophytes, flowering behaviour and development of tetraploids. Estimates of the genetic progress for annual yield are between 0.25 and 1.5% per year (Easton et al 1997, 2001, Woodfield & Easton 2004, a rate comparable with white clover and other crops. However, in practice cultivars are used in mixtures with white clover and any genetic increase in the ryegrass component may partially suppress clovers to limit increases in overall pasture yields.…”

Genetic improvements in New Zealand forage cultivars

“…The 1.18% increase in annual ryegrass annual yield was almost double that reported for annual ryegrass (0.5% per year) in Europe (van Wijk & Reheul 1991). Further evidence of genetic improvement in annual ryegrass yield can be observed from the performance of G. Moata, the control cultivar used by Easton et al (1997). G. Moata was consistently amongst the poorest performing cultivars for seasonal and annual yield (Easton et al 1997), however, when it was first released it yielded 15-20% better than the next best annual ryegrass (Rumball & Armstrong 1975).…”

“…Genetic improvement in seasonal yield of annual ryegrass (derived from Easton et al (1997) data; 11 cultivars with yield from between 7 and 16 trials). and in the associated endophyte strain (Westwood & Norriss 1999).…”

Evaluating perennial ryegrass cultivars: improving testing

“…Genetic improvement of pasture plants has been pursued for over 85 years (Wratt & Smith 1983), with documented gains in dry matter (DM) production, disease resistance and forage quality (Corkill 1949;Kerr 1987;Easton et al 1989;Easton et al 1997;Woodfield 1999;Easton et al 2001). Genetic gains averaging around 0.5% per year for total annual DM yield (Lee et al 2012) have been demonstrated through small plot trials (Kerr 1987;Pennell et al 1990;Easton et al 2001;Hume et al 2007).…”