Impact of sowing time on ryegrasses in the South Island

In winter 2019, we set out to learn more about Winter Star II and Supercruise. We ran tests and measured the accumulated dry matter production (kgDM/ha) to find out what role sowing dates play, and which conditions each variety prefers on our test farm in Lincoln, Canterbury. 

Impact of sowing date on Winter Star II Production

In autumn 2019 the impact of two sowing dates (6th March 2019 and 10th April 2019) on Winter Star II production were evaluated. Key findings are presented below:

6th March Sowing

• 63 days to first grazing on the 8th May 2019
• Accumulated 11,281 kgDM/ha to final yield assessment on 31st October 2019

10th April Sowing

• 146 days to first grazing on 30th July 2019 – essentially no grazing until late winter
• Accumulated 8,216 kgDM/ha to final yield assessment on 31st October 2019 

From August onwards sowing date had no impact on daily growth rates. Both sowing dates had average daily growth rates of approximately 72 kgDM/ha/day.

Key takeaway

Only consider planting annuals in late autumn if feed is not required until late winter/early spring. If significant winter feed is required, consider oats or ryecorn for late sowings.

Winter Star II vs. Supercruise - Late Sowing

On May 3 2019, we also set up a demonstration to compare Winter Star II annual ryegrass and Supercruise Italian ryegrass was established. Key observations from this demonstration are presented below:

Key takeaways

Winter Star II

• Great later winter and early spring production
• Growth slowed in late spring as plants went reproductive and began to die off
• By mid-December plant numbers were less than 50%; production was minimal and mostly stem/seed head
• Accumulated 10,256 kgDM/ha to final cut on 24th December (no further production possible)

Supercruise

• Slightly less early season growth than Winter Star II but greater late spring and early summer growth
• Accumulated 12,705 kgDM/ha to latest cut on 9th March with pasture suitable to produce for another 12 months
• To maintain quality during summer stick to tight rotations to avoid plant producing stem and seed head
• Will persist for 18-24 months so can carry through the winter and into next spring

You can download this trial update in PDF format via the link below.