- Endophyte levels in ryegrass seed drop off over time.
- On-farm, store seed with novel endophytes in a cool, dry place. Sow seed within one month of purchase.
- Commercial ryegrass seed with novel endophyte (e.g. NEA2, AR37) is carefully carried over between seasons using controlled humidity cool storage.
Endophyte in seed
Seed is a living organism and should always be stored in cool, dry conditions. But endophyte is particularly important as its levels in ryegrass seed drop over time much more quickly than seed germination levels. This speed of decline in endophyte is influenced by humidity, temperature, and endophyte strain.
More planning for seed purchase is now required when dealing with novel endophytes such as AR37 or NEA2. Ideally seed should arrive on farm within a couple of weeks before sowing, and we recommend it be sown within one month.
Store seed on-farm in a cool, dry place until sowing. Seed containing novel endophyte should not be carried over between seasons on-farm as the endophyte is likely to be lost. Therefore ordering the correct amount of seed is important.
Barenbrug has set up a cool store seed distribution plant at Rolleston to provide a just-in-time inventory system. Seed is kept in low temperature and relative humidity storage as long as possible to maintain its endophyte levels, with seed delivered within 3 days of order.
Storage between seasons
Not all seed can be sold in the year it is harvested, due to the limited time between harvest (particularly of late heading cultivars) and farmer pasture sowing requirements.
Endophyte levels are safely maintained between seasons in low humidity, low temperature storage. All seed with AR37 or NEA2 endophyte carried over is placed in cool storage as soon as possible after cleaning, and endophyte levels are re-tested prior to sale.