CANOLA growers are likely to suffer yield losses if they use grain from hybrid crops as seed for planting the following season's crop.
Pacific Seeds southern region sales manager Michael Uttley said farmers were "bloody stupid" to retain hybrid seed for sowing future crops.
Speaking at the Grains Research and Development Corporation research update in Ballarat last week, Mr Uttley said trials from 2007 to last year in Victoria and South Australia growing canola crops using seed from five hybrids had shown yield declines of 10-30 per cent.
He was "alarmed" about reports agronomists were advising farmers to use hybrid canola seed to grow the following season's crops.
When seed is derived from cross-pollination of two pure parent lines, it produces a hybrid known as an F1 cross, with superior improvement in performance.
Seed taken from an F1 hybrid to grow the following season's crop is known as F2 seed.
Mr Uttley said seed from an F1 crop (F2 seed) or subsequent generations (such as F3, F4) was not a hybrid, but an open-pollinated variety.
Trials last year using hyola50 at three research sites in northern Victoria showed a mean yield of 2.09 tonnes/ha for the F1 cross, 1.75 tonnes/ha for the F2 line and 1.59 tonnes/ha for the F3 line.
Mr Uttley said that translated into a $134/ha loss for the F2 crop and a $190/ha loss for the F3 crop, based on a canola price of $400/tonne and 42 per cent oil content.
He said the trials showed F1 hybrids had 10 per cent greater plant establishment and higher visual biomass than the F2 lines.
He said F2 populations showed a 10-day variation in flowering, 10 per cent higher lodging and 30 per cent variation in height than its parent.
On top of that, 25 per cent of the F2 crop was sterile.
Mr Uttley said he would "question the direction or logic in retaining either hyola50 or hyola571CL seed for an F2 crop".
"Any recommendation based on keeping hybrid seed for the next generation is poor and misguided advice," he said.
Trent Potter, senior research scientist with the South Australian Research and Development Institute, told the conference using retained hybrid seed also ran a higher risk of blackleg infection.
But Mr Potter said it depended on which hybrid variety the seed was sourced from to grow an F2 crop.
"On an individual plant basis, our trials showed more internal infection from blackleg when retained seed was used than with the hybrid," he said.
