Among recent canola releases is Karoo. an early maturing triazine-resistant type.
And among the growing number of farmers to try this variety is Garry Hansen of Coomandook in SA's upper south-east.
This area was not traditionally regarded as a canola district, but innovative farmers and plant breeders have stretched the canola-growing boundaries in recent years.
Mr Hansen, who continually crops about 2,300 hectares a year in this 420 mm rainfall zone, first tried canola four years ago with Rainbow. However, brassica weed in the form of radish and mustard proved a problem, so in 1996 he planted triazine-resistant Karoo which has a flowering date similar to Rainbow's.
Using a Connor Shea airseeder Mr Hansen cultivates his sandy loam soils to a depth of about 6 cm and applies urea, 100-120 kg/ha before seeding.
When germinating weeds have been controlled (Mr Hansen used a strategy based on triazine chemicals - rates depending on weed spectrum and size), the canola is sown with 'narrower points' and a prickle chain to seeding depth of about 2 cm. During seeding he applies DAP at 90 kg/ha with 2.5 per cent zinc.
The paddock is rolled straight behind the airseeder to compact the seedbed and roll in stones. Mr Hansen says the deeper-than-normal seeding seems to suit canola germination in his area because he doesn't have a soil crusting problem but rather a soil that can dry out quickly.
"We aim for 50- 70 plants per square metre and do sap nitrate tests to monitor crop nutrient status," Mr Hansen said.
"We had been told that triazine-resistant types would yield less than varieties like Rainbow. That wasn't the case with Karoo last year although there could have been some yield losses in the Rainbow due to heavier weed infestations."
Mr Hansen's Karoo crop in 1996 yielded 2 t/ha with more than 40 per cent oil, and earned him an Encouragement Award in the Meadow Lea National Canola Awards.
It also encouraged him to sow the variety again this year along with two other new releases, Pinnacle and Clancy.
"Pinnacle and Clancy don't look too bad (early August) but let's wait to judge them after the grain is in the bin," Mr Hansen said.
His overall assessment: " I'm surprised how easy canola is to grow. It just needs a bit more monitoring"
Subprogram 2.5.2 Contact: Dr P Salisbury 03 9344 7315