KEEPING hybrid canola seed for next season could save up-front seed cost, but could cost a 20 per cent yield penalty.
That's the view of the Department of Agriculture and Food (DAFWA) researchers who are running a hybrid canola seed trial at Dalwallinu and Merredin this year to establish the level of vigour degradation when seed is retained.
Speaking at the Liebe Group post seeding field walk last week, DAFWA senior research officer Bob French said as seed companies reduced their research in open pollinated (OP) varieties, growers may be forced to use old OP seed or switch to hybrids.
"Most seed companies are putting the bulk of their effort into developing new hybrid varieties, however the advantage with OP varieties is that growers can keep their own seed so the initial seed cost is much cheaper," he said.
Dr French said due to the upfront cost of hybrid seed, DAFWA's research aimed to see if it was practical for farmers to keep their own hybrid seed for two or more generations before the hybrid vigour degraded too much.
While not an option for Roundup Ready (RR) hybrids, this could be of benefit for triazine tolerant (TT) hybrids.
Dr French said hybrid seed retention was particularly attractive in the lower yielding areas.
"CSIRO research suggests that in low yielding areas when the yield potential is below 1.3 tonnes per hectare, there are no advantages to growing hybrid vigour in terms of gross margins when you take seed cost into account," he said.
"To get the best out of hybrids, you need to be in a good yielding area so for large areas of WA's low rainfall environments that don't produce more than 1.3t/ha, growers might find that in the future they are forced to use hybrids but not get the advantage, so seed retention could help with keeping costs down."
Dr French said trials conducted by DAFWA last year showed a penalty in canola yields when growing second generation (F2) hybrid seed.
"On average, we saw a 20pc decrease in yields from Hyola 450 F2 hybrids, with the penalty tending to be lower in lower yielding sites.
"This result is consistent with Canadian research and earlier Australian research," he said.
Trials have shown that the yield penalty could be mitigated by grading the seed or using different rates.
This year the trial was expanded to include a second hybrid variety, Hyola 559, and would also include third generation (F3) Hyola 450 seed.
"We have added an additional variety as different hybrids might behave differently and Hyola 559 has been one of the best performers," Dr French said.
So far this year, results have been neck-and-neck in regards of germination, with only slight differences in crop vigour.
"We haven't seen any difference in establishment of the two varieties," Dr French said.
"However, we are monitoring crop vigour using WeedSeeker technology and this is showing that the true hybrids are more vigorous than the F2 and F3 generation."
Dr French said when larger seeds were graded out in the F2 and F3 plots they retained the same vigour, but it remained to be seen if this would translate to a difference in yield at harvest.