Caption 1: CSIRO’s GRDC-funded early sowing of wheat trial site at Wickepin last year shows a range of plant development rates dependent on time of sowing and use of long, mid or short maturing variety. Photo: CSIRO.
Caption 2: DAFWA grains industry research officer Christine Zaicou-Kunesch is analysing early sowing of mid and longer season wheat variety performance as part of the GRDC-funded WA wheat agronomy project. Photo: DAFWA.
KEY POINTS – Considerations for early sowing and use of longer maturing wheat varieties:
- Avoid dry sowing, as seed bed moisture is needed for early establishment.
- Sow at a lower plant density and reduce up-front Nitrogen if not crop grazing.
- Use paddocks clean from weed and disease pressure.
- Protect crops against diseases associated with early sowing.
When planning wheat plantings for 2015, don’t overlook the value of bringing sowing dates forward and using longer maturing varieties.
This tactic can take advantage of any early rain and help to mitigate spring frost risks.
Preliminary results from new GRDC-funded research projects in WA show that sowing early with mid and longer maturing varieties can be a viable option and has potential to lift whole-farm wheat yields and profits, especially in mid-high rainfall zones.
This is driven by the yield advantages of these wheats and opportunities for more timely planting of mid and short maturing varieties when some farm area is sown early.
CSIRO Agriculture and the Department of Agriculture and Food, Western Australia (DAFWA) have set up GRDC-funded trials across the WA grainbelt comparing yields from a range of longer and mid maturing varieties – sown early - with yields from short maturing varieties (mainly Mace ) when these are sown in their optimal window.
Key findings from the first year of these trials in 2014 are outlined below and will be presented at the WA Agribusiness Crop Updates, to be held on February 24-25 at Crown Perth. Registrations and the full program for the Updates are available at: http://www.giwa.org.au/2015-crop-updates
Early sowing of wheat in WA – CSIRO’s first year trial results
The 2014 CSIRO trials at Cunderdin, Doodlakine, Wickepin and Kojonup were carried out in conjunction with the WA No-Tillage Farmers Association, Facey Group, Living Farm and Eurofins and will be repeated this year.
The trials included six ‘best bet’ commercial varieties of varying maturity and four near isogenic lines (NILs) as a research tool to help identify genotypes best suited to early sowing in WA. Times of sowing were mid-April, early May and mid-late May.
As shown in Tables 1-4 (below), the trials generally found the best long and mid maturing varieties – sown early in March/April – produced similar yields as the common mid-short maturing varieties – sown later in or after May/June – when they flowered at the same time.
This was attributed to increased rooting depth and water use, less evaporation and increased transpiration efficiency when sowing early and reflects similar findings from CSIRO trials in south-eastern Australia, according to CSIRO’s Dr James Hunt.
He says this potentially provides WA growers with some alternative variety options if there are sowing opportunities from March through to late April.
This is when the commonly used mid-maturing varieties in WA (eg. Yitpi and Magenta ) are suitable.
At the Doodlakine and Wickepin sites, as shown in Tables 1 and 2, the best long maturing wheats - sown early – yielded as well or better than Mace sown in its optimal window.
The Doodlakine site was dry, but both of these sites were relatively frost-free in 2014 and generally varieties that flowered earliest (Lancer , Magenta and Mace ) tended to yield the highest.
Table 1. Yield results for Doodlakine (Source: James Hunt, CSIRO).
Table 2. Yield results for Wickepin (Source: James Hunt, CSIRO).
The Cunderdin site was sown wheat-on-wheat. Spring wheat volunteers and high levels of rhizoctonia bare patch compromised the earliest sowing date across most varieties, especially Whistler and Wedgetail , as illustrated in Table 3.
James says this reiterates the importance of using clean, weed and disease-free paddocks for early sowing of longer maturing wheats – and after canola or long fallow is ideal.
He says under weed and disease pressure, Mace and Magenta were the outstanding varieties at Cunderdin last year and the trial highlighted the value of tag-teaming these varieties to optimise whole farm wheat yields.
Table 3. Yield results for Cunderdin (Source: James Hunt, CSIRO).
Good late season growing conditions were experienced at the Kojonup trial site and, as shown in Table 4, the highest yielding option was Magenta sown on June 2.
All varieties sown at the earliest sowing date were compromised at this site by high levels of annual ryegrass.
Table 4. Yield results for Kojonup (Source: James Hunt, CSIRO).
Across all of the 2014 CSIRO WA trial sites, results indicated that the short maturing winter wheat, Whistler, appeared to adapt well to local conditions when sown early.
When planted in mid-April, it yielded as well as – or better than – Mace planted in late May at three out of four trial sites.
James says using a variety such as Whistler to bring sowing dates forward would allow growers to take advantage of early planting opportunities across a broad window from late March to early May and its stable flowering date would reduce frost risk.
But he says this variety - and some other longer maturing lines – could be limited by inferior quality classification and low seed availability.
James says this reinforces the value of research to find modern, high quality winter wheat varieties adapted to WA conditions that can help increase production and reduce frost risk. This is a main reason why NILs are included in the WA trials.
In 2014, the NILs confirmed the results of the commercial lines - in that the short maturing winter line (similar to Whistler) achieved the highest yields from the mid-April sowing date. This was 17 per cent higher than the fast spring line (similar to Mace ) sown in late May.
James says this represents the level of yield gain possible if adapted winter wheats able to be sown early were available to WA growers.
He says 2014 was relatively frost free at all trial sites and the short maturing spring wheats performed better than would be expected from the mid-April and early May sowing dates.
DAFWA’s 2014 long season wheat trial results
DAFWA’s new wheat agronomy project ‘Tactical wheat agronomy in the west’ – which started in 2014 – is also evaluating early sowing of mid and longer maturing lines from breeding companies in trials across WA that are designed to maximise yield potential.
DAFWA grains industry research officer Christine Zaicou-Kunesch says the big risks of sowing mid and longer maturing varieties earlier in the season in WA are weeds, disease and poor establishment.
But these risks can be reduced by using suitable varieties and tools such as modern no-tillage techniques, summer fallow management and more cost-effective insecticides and fungicides to protect against pests and diseases.
Christine says mid-long maturing varieties – such as Yitpi , Magenta , Calingiri and Stiletto – have a place in WA cropping systems and still make up nearly 25 per cent of the State’s wheat crop area (with short-mid maturing Mace and Wyalkatchem sown on about 65 per cent of wheat crop area).
She says the National Variety Trials (NVT) system tends to be geared towards evaluating the short maturity lines, but some mid and longer maturity varieties have shown to produce competitive yields in many agricultural zones.
This year’s NVT trial data includes more detail about wheat variety performance across several years in a range of environments.
DAFWA will continue its wheat trial at Merredin in 2015 using irrigation to simulate early sowing opportunities and assess yield response from longer maturing varieties.
Separate wheat agronomy project trials will also continue at sites from Geraldton to Esperance investigating flowering response of wheat varieties sown from early April to mid-June as part of efforts to quantify the impacts of early sowing and spring frost.
James Hunt, CSIRO
02 6246 5066
08 9956 8549
Melissa Williams, Cox Inall Communications
042 888 4414
2015 WA Agribusiness Crop Updates Program and online Registrations: http://www.giwa.org.au/2015-crop-updates
NVT online: www.nvtonline.com.au
2014 Wheat Variety Guide: https://www.agric.wa.gov.au/grains-research-development/wheat-varieties-2014
GRDC Project Code
CSP00178; DAW00218; DAW00229