Retaining seed: RISKS TOO HIGH by Gary Alcorn
GroundCover™ Issue: 39
WHILE FARMERS traditionally retain future planting stocks of cereal seed using simple precautions, keeping canola seed is fraught with unacceptable financial risk, according to Canola Association of Australia president Steve Brill.
He fully supports the 1999 research findings by Victorian pathologist Steve Marcroft which identified uncertain seed germination and vigour, and genetic drift as the major hazards associated with farmer-retained canola seed (FRCS). That research was supported by growers and the Federal Government through the GRDC.
"As a professional canola seed grader with 21 years' experience, I know it's cheaper to keep your own seed rather than buy fresh certified stock each year, but there are hidden costs in this DIY strategy.
Weed seeds are just one hazard, which can be reduced by cleaning. However, uncertain germination and resulting overcompensation in sowing rates can play havoc with plant populations, management decisions and yields."
He said certified canola seed had less than 0.1 per cent (mostly nil) weed seeds based on sample analysis, while some new seed protectant coatings could only be applied professionally and were not available to FRCS.
Mr Brill believes around 30 per cent of farmers in his home base of Young, NSW, retain canola seed while the CAA has reports that 70-90 per cent of WA canola growers use FRCS.
In comparison, 80 per cent of Canadian growers use certified seed. There, recent research showed a 7 per cent yield penalty . from retained seed. Australian trials have established similar yield penalties.
"In WA the major concern with multiple generations from FRCS is the build-up of erucic acid and glucosinolates, which are unwelcome in the margarine industry, while on-farm seed treatment with fungicides can be inconsistent," he said.
Seed storage conditions must be just right
On-farm storage conditions for canola are much more critical than for cereals. Seed moisture percentage control is a key factor in on-farm canol a because overheating (above 34°C) is a risk. The combination of high moisture content and 40- 50 per cent oil means canola seed can deteriorate quite quickly, he says.
So the CAA's official line is 'Don't keep your own seed' - it's not in your best interest and it doesn 't help the quality reputation sought by the canola industry, Mr Brill advises.
Western Victorian grower Brian Uebergang agrees. This season, as in most years, he grew 105 ha of canola for certified seed supplier Dovuro and doesn' t keep one seed for his own purposes on his property at East Lynne in the Natimuk district. "It's not worth the trouble and the risks - the bought seed has known germination, it's pure with no throwbacks and can be delivered pretreated with chemicals to control false wireworm. The most important thing with certified seed is you keep the varietal line true to type;' he said.
Dr Marcrof! found that growers were risking crop failure or inferior yields in order to save, in most cases, less than $10 per hectare when the cost of grading, storage and testing FRCS was considered. Problems with canola seed viability were exacerbated when compared to other crops due to canola's small seed size.
Program 2 Contact: Dr Stephen Marcroft 0353622111 email Steve.Marcroft@nre.vic.gov.au