Farmers are being urged to take extra care when storing seed delivered before sowing.
The Plant Breeders and Research Association (PBRA) says appropriate storage of seed is vital to ensure good germination and growth to its full potential.
Graham Kerr, pasture specialist with PBRA member company Barenbrug, says once seed leaves the specially designed cool stores operated by most seed companies and is delivered to a retailer or farm, speed to sowing is critical.
“We have to remember that a seed is a living thing that is constantly breathing. So, it responds to how we store and treat it,” he says.
Mixes containing ryegrass bred with desirable endophytes are particularly sensitive to changes in humidity and temperature during storage.
“Endophyte is the first thing to fall off over time, depending on the storage conditions, and then germination will drop later too,” Kerr says.
Clover keeps for longer than grass seed because it has a hard seed coat, and most lines contain a good percentage of ‘hard’ seed.
Kerr says seed companies like Barenbrug take the care of their product very seriously.
“Seed stewardship is in our DNA as a seed company. It’s paramount to what we do. We live it and breathe it.”
“We take every care to ensure the seed is in the best condition when it leaves us. Then we’re reliant on resellers and farmers looking after that living product from then on,” he says.
The company works closely with resellers to ensure just-in-time delivery and advises farmers to get their seed sown within four weeks of it arriving on farm. When seed is stored on farm, keeping it dry and as cool as possible is important.
Small seeds destined for the retail trade are grown by specialist growers and supervised by agronomists to ensure it is well cared for through to harvest.
After dressing, seed is tested for purity and germination through a prescribed sampling and testing regime which is independently audited. Seed laboratories in New Zealand must maintain accreditation to the International Seed Testing Authority, ensuring a high standard of testing, and tests have a six-month life.
Ryegrass samples containing endophyte are also tested to assess endophyte levels.
To preserve ryegrass seed endophyte at the required levels, seed companies have invested in temperature and humidity controlled cool stores.
Kerr says endophyte levels on ryegrass lines stored in a cool store will last many years compared with just 12-18 months when stored in an uncontrolled facility.
“And, it’s worth noting that a number of those months are actually spent prior to us getting it in a cool store because the seed harvested in late January and February and it might be on farm for a month and then it could take up to six months to dress it,” he says.
Another PBRA member, Genetic Technologies, also operates a ‘just-in-time’ approach to delivering its maize seed to merchant stores ahead of the hectic planting window between early September and early December each year.
The company’s Maize Product Manager Barry McCarter says the aim is to have the product delivered to merchants near to the time it is due to be planted by a contractor or farmer.
“Seed is a living organism, and it needs to be treated accordingly. So, if it gets thrown around in the distribution process or stored in a hot shed, at high temperatures, the seed is not going to enjoy that,” he says.
“Fortunately, maize seed is treated and distributed during the cooler months of the year, so the inherent quality of the seed is maintained with the application of reasonable care over this period.”
Genetic Technologies builds quality into the end-to-end maize seed production process from the paddock to the bag at its Gisborne production facilities. The final step requires the rigorous testing of every hybrid, seed size and treatment combination to ensure genetic purity, germination and vigour of each batch of seed.
The PBRA and its members offer extensive advice to farmers on cultivar selection, seed storage and planting while also providing regular training sessions for technical advisor teams at reseller companies and contractors.