Establishment and management of novel endophyte ryegrass pastures to minimise contamination from wild-type toxic endophyte
Establishment of Novel Endophyte Ryegrass Pastures
Aim: To start with a clean paddock free of any growing perennial ryegrass and free of any existing ryegrass seed. This will generally mean elimination ryegrass from the old pastures between November and Autumn sowing.
Thus sow novel endophyte ryegrass seed only in the following situations:
- Following a winter/spring/summer forage crop such as a brassica (turnips, Pasja, Kale, Rape), oats, forage maize, sorghum, or nil endophyte ryegrass (i.e. annual or short term hybrid only).
- Following a summer fallow, with cultivation commencing prior to November, when reproductive development is occurring in ryegrass, and eliminating any re-growth ryegrass plants over summer.
- Following an arable crop such as wheat, maize, barly, peas, etc, or after maize with subsequent winter fallow or crop.
- Following a double spray with glyphosate (or similar herbicide), spraying in late November and again in February.
- Following a closely grazed and managed pasture through summer that has prevented any seedhead production, in a high rainfall area where seed fall or dormant seed are not usually a problem. Then sprayed out with relatively high rates of glyphosate (or similar herbicide) and conventionally cultivated or direct-drilled.
- Following a silage crop that has been cut before ant visable seed has been produced, and then sprayed out using relatively high rates of glyphosate (or similar herbicide) and conventionally cultivated or direct-drilled.
- As endophytes are not effective during germination and establishment period (six weeks), seed coating and insecticide is strongly recommended.
- In summer dry regions (Canterbury, Otago, East Coast North Island), particularly where ryegrass exists in resident pasture, the paddock should ideally be out of ryegrass for two summers to ensure ‘pure’ novel endophyte ryegrass effects.
- Do not feed out hay made from high endophyte (wild type) perennial ryegrass pastures in the novel endophyte ryegrass paddocks for the 12 months prior to establishment.
- Livestock that have grazed high endophyte (wild-type) ryegrass pastures with seedheads should not be moved directly on to the paddock sown in novel endophyte ryegrass during the summer and autumn prior to sowing, in order to prevent ryegrass seed being transferred in dung. The “with-hold period” should be three days.
- It should be emphasised to users that direct grass to grass renovation is not a suitable method of establishing novel endophyte ryegrass pastures, because of the high potential for contamination.
- If sowing other ryegrass in the seed mixture, these must be nil endophyte (i.e. annual or short-term hybrid) or another ryegrass cultivar with novel endophyte ryegrass.
Management for established pastures of novel endophyte ryegrass
Aim: To prevent seed of standard endophytes being transferred into novel endophyte ryegrass paddocks by:
- Do not feed out hay made from standard endophyte ryegrass pasture in novel endophyte ryegrass paddocks.
- Try to prevent the movement of livestock from standard endophyte ryegrass pastures that have seedhead present, to novel endophyte ryegrass pastures, as animals can spread seed through dung. The “with-holding period” should be three days.
- Minimise contamination from seed carried on farm machinery that enters novel endophyte ryegrass pastures.
- Renovation of novel endophyte ryegrass pastures by undersowing should only be done with novel endophyte ryegrass seed.
- Very little can be done about transfer of seed in pelts.