WHEAT crops sown before mid-May are likely to reap the highest yields in 2016, according to trial results from the Eyre Peninsula and Mid North.
CSIRO senior research scientist James Hunt said a variety trial indicated that time of sowing and variety selection were crucial to obtain maximum yields.
“The main finding across all SA trials in the GRDC early sowing project is that the yield of Mace and Trojan decreased at 28 kilograms a hectare per day that sowing is delayed past May 8,” Dr Hunt said.
“Therefore, growers should aim to finish sowing wheat by mid-May.
“In years where there is seedbed moisture, they can pick up a yield advantage by sowing the mid-maturing cultivar Trojan in late April before switching to Mace in May.”
Dr Hunt has been working with SARDI, the Mid North High Rainfall Group and Hart Field Site Group, which have run trials across the state since 2013.
“I’ve been leading a GRDC-funded national project looking at sowing wheat earlier than practiced, and how this can be achieved in different regions,” he said.
If there is an early break and adequate seedbed moisture, he said research indicated that farmers should start on April 20 with Cutlass.
He recommended switching to Trojan on April 25 and then moving on to Mace or another fast wheat variety such as Scepter or Corack on May 5.
If there is no seedbed moisture and no rain on the eight-day forecast, growers are advised to sow Mace or a similar variety dry on April 25. In frost-free coastal locations, yields can be further increased by starting sowing in mid-April.
In frosty locations, there are no cultivars suited to SA that can safely be sown before April 20, and slow developing cultivars from other states such Wedgetail wheat do not yield well in SA.
“But, there are new winter wheat varieties under development by breeding companies which performed well in trials in 2015,” Mr Hunt said.
“SA growers will hopefully have some good options for early sowing in the next few years.”
Because most SA environments go from being frosty to hot and dry quickly in spring, the time at which wheat flowers is crucial for yield.
