Harvesting of South Australia's network of multi-site, multi-year wheat variety trials is about to get underway to provide crucial production data that will help inform growers' crop choices for coming seasons.
This year, 35 sites were sown to newly released and commonly-used wheat varieties through the National Variety Trials (NVT) program - which is a Grains Research and Development Corporation (GRDC) investment on behalf of Australian grain growers.
Trial results for crop yield, grain quality and disease tolerance will feed into the SA Crop Sowing Guide, which will hit mailboxes in coming weeks to underpin decision-making for season 2021.
The SA wheat NVT trials were sown across the South East, Mallee, Lower Eyre Peninsula, Upper Eyre Peninsula, Yorke Peninsula and Mid North.
There were several new varieties released in 2020 that have been assessed through the NVT program.
These include milling wheats, BASF Ascot and Australian Grain Technologies' (AGT) latest lines Ballista, Denison, and the Clearfield variety Hammer CL, along with the feed wheat Anapurna.
There were also six durum wheat varieties in the mix at many of the SA NVT sites, including recently released DBA Spes, DBA Artimus, Westcourt and Bitalli.
The GRDC NVT 'early break' trials will be particularly useful to assess the performance of Denison, as it may provide another option for sowing in mid-late April, and Anapurna, which is a slow developing winter wheat with feed classification and has achieved high yields in the high rainfall zones of the South East.
Catapult was another release from AGT and is promoted as a 'longer season' Scepter, with a mid-slow maturity that has potential for high yields when sown in late April.
Hammer CL Plus has been found in trials to be the highest yielding AH Clearfield wheat variety for SA.
Yield and grain quality data from all the wheat varieties tested through this year's NVT will be released by GRDC when available and be included in the 2022 SA Crop Sowing Guide.
There will also be comparisons between developmental speed and disease resistance for each variety and, as always, growers are encouraged to consider long-term yield performance data.
South Australian Research and Development Institute (SARDI) research scientist Kenton Porker said trial sites were looking good this year after an excellent season start across most of SA and limited spring frosts. But this was slightly tempered by a prolonged dry period in late winter.
He said the majority of NVT wheat sites were able to be established on time due to widespread ANZAC Day-breaking rains through to mid-May.
Two 'early break trials' were sown in mid-April to assess the performance of slower developing wheat varieties.
Dr Porker said it would be interesting to compare performance of the newer, faster developing wheats - such as Vixen and Ballista - to the slightly slower developing wheats - such as Catapult, Trojan, and Rockstar.
"Based on environmental conditions in 2020, it is feasible to speculate that many of the fast maturing wheat varieties may have suffered from drought stress at the critical pre-flowering stage, which could impact on grain yield and quality," he said.
Dr Porker said late spring rainfall in many areas of the state would have boosted yield expectations for the slow maturing crops and later sown crops that could still capitalise on late spring rainfall.
"While there is always significant frost damage in SA, damage across the trials appears to be less severe compared to previous years - although there will be crops affected in regions that did get some frost at the critical grain fill time," he said.
Dr Porker said the NVT wheat trials coordinated by SARDI and Frontier Farming Systems in the Mallee region were on track to be much better than the past two seasons, as this area - particularly the southern Mallee - had an exceptional spring.
He expected yields would be above average - at about three or four tonnes per hectare.
"The past two years have been very dry in this region, so it has been great to see a turn-around in conditions," he said.
Dr Porker said the northern Mallee region NVT sites may have wheat yields of about 2t/ha, while parts of the upper Eyre Peninsula were looking at below average yield potential.
GRDC NVT manager - south, Rob Wheeler, said key to reaping the best information from the NVT trials was consistent crop management practices across all trial sites.
He said these strict protocols were based on 'good district practices', without aiming for high-input, optimum-yielding systems.
Mr Wheeler said many trial sites had experienced relatively high levels of crown rot this season, which may impact on yields - especially for durum wheat varieties that were more susceptible.
"We may get some really valuable data from the trials about crown rot tolerance among the new wheats," he said.
Mr Wheeler said growers are best advised to use the new 2020 SA Crop Sowing Guide when planning rotations for next season.
"Coupled with this, it is good to note any issues that you see at harvest time in regards to potential yield fluctuations due to factors such as weeds or disease," he said.
"And always choose a suitable variety for the location and environment."
For the NVT wheat harvest results, keep an eye on the website at www.nvtonline.com.au.
And watch out for the latest SA Crop Sowing Guide, compiled by SARDI, now available via https://grdc.com.au/NVT-south-australian-crop-sowing-guide and NVT Online.
