Pasture Persistence & Genetic Gain

Cáthal Wims on behalf of colleagues in the Feed and Farms Systems Team

Pasture Persistence Project

• Improve our understanding of pasture persistence

• Collect information on:

– Perennial Ryegrass cultivar

– Sowing rate

– Characteristics of surviving plants

vs.

How are we doing this…• 4 cultivars

– Nui SE– Commando AR37– Alto AR37– Halo AR37

• 5 sowing rates– 6, 12, 18, 24 and 30 kg/ha

• 3 sites– Northland; Waikato; Canterbury (irrigated)

What we found so far…

• Modern cultivars are not less persistent than Nui – In fact, could be reverse

• Nui based pastures higher % weed species

• Sowing rate – 12 – 24 kg seed/ha = similar performance– Opportunity to lower seeding rates under ideal sowing

conditions

Genetic Gain in Ryegrass • Gain delivered by plant breeding?

– Old vs. modern cultivars?

• Trials established in Waikato and Canterbury

• Cultivars included– Mid and late heading Diploids– Late and very late heading Tetraploids

Measuring gains in…• Dry Matter Yield• Pasture Quality • Persistency

• Evaluated under grazing

gains in profitability being delivered by plant breeding to NZ dairy farmers

• Late and very late heading cultivars

– Delayed reproductive development

– Fewer reproductive tillers

Less of this in late spring and early summer

Heading dates

In summary• Work underway to…

– better understand perennial ryegrass persistence– Comparing old vs. modern cultivars

• No evidence that modern cultivars are less persistent than Nui

• Plant breeding has successfully altered heading date– Delayed reproductive development in spring