The NZ Plant Breeders and Research Association (PBRA) says using cheap common cultivars or unknown seed instead of modern options are often false economics for those trying to reduce costs on their farms.
Choosing to go with proprietary seed cultivars, which have been through a rigorous breeding and selection programme, is the wiser option, according to the PBRA.
New seed lines can take more than a decade and cost about $1 million to develop before they go on the market.
PGG Wrightson Seed marketing general manager Alick Elliott said a cheap common cultivar such as Nui or an uncertified or unknown seed might seem appealing until the potential risks were considered.
"Firstly, you know what you’re getting in the bag if you choose a proprietary cultivar or a proprietary seed mix. It’s really that simple. If you’re buying seed that is uncertified or from an unknown source, you could be buying a long-term problem."
He said unknown seed could contain a lot of weed seed that would take years and expensive chemicals to get under control.
Or a rejected low germination line could compromise establishing a crop or regrassing. Animal performance would be lowered if it was full of wild-type endophyte, he said.
"A large part of the cost of establishing a new pasture occurs before the sowing of seed with ground preparation and fertiliser application, so cutting costs on seed after this expenditure is just not worth the risk,” he said
Most PBRA proprietary cultivars are tested in the independently run national forage variety trials. Trial results help farmers select cultivars to improve their farm system and deal with pest or disease challenges.
Germinal Seeds general manager Simon Larsen said farmers could miss out on decades of genetic gain in plant breeding by choosing common seed.
Seed breeders continued to invest millions in breeding new cultivars that come with the latest endophytes which help plants cope with pest issues, such as Argentine stem weevil or black beetle attack, he said.
Mr Larsen said proprietary seed options came with agronomy support and advice.