Innovations around sowing time are transforming farming practices in ways that make yields more stable and cropping more adaptable to varying climate conditions.
By Elizabeth von Perger, Stirlings to Coast Farmers
Wheat varieties are being tested at a range of different sowing times to optimise options for growers facing increased seasonal variability in Western Australia.
While a broad range of research activities are underway, two projects driven by the National Grower Network (NGN) in particular are testing very early and late sowing times.
Growers have played pivotal roles in both projects, showing keen interest in sowing time innovations through the NGN and through direct involvement in the Stirlings to Coast Farmers group.
The early sowing trial got underway this year, 2023, in the Albany port zone with the aim of better exploiting a climate trend towards more late-summer rainfall in the region. Winter wheats form the basis of these trials.
While this class of wheat might have started out in grain-and-graze enterprises, it is gaining popularity as a way to close the yield gap in crop-only systems. The winter wheat varieties are:
- RGT Accroc;
- DS Bennetta;
- IGW6755 (Intergrain);
- RGT Cesarioa; and
The trials involve strip lengths of at least 250 metres, with the last 70 to 80m remaining fungicide free to understand issues around disease resistance.
The strips were sown in the first week of April. Yields and performance are due to be compared with an adjacent paddock of spring wheat (Scepter) sown at a typical seeding date (mid-May).
The trials are being monitored for:
- soil characteristics;
- plant counts;
- plant tissue tests;
- disease scoring; and
- harvest yield.
Extensive issues with waterlogging throughout 2020–22 motivated efforts to understand how late a paddock can be sown while still achieving economic returns on WA’s southern coast. This region is prone to waterlogging that can reduce yields by up to 36 per cent, so the trials are exploring an important local agronomic issue.
The 2022 trials pushed the envelope on sowing time to an extraordinary extent – with sowing taking place as late as September.
The project comprised four plot trials scattered from Albany (Green Range and Needilup) to Esperance (Munglinup and Condingup). Each site included:
- three sowing times – late August, mid-September and late September;
- a main season and a quick-maturing wheat variety (Scepter and Vixen) and three barley varieties (Maximus CL, RGT Planet and Rosalind); and
- two nitrogen treatments (80 and 40 units of nitrogen).
Crop establishment, growth stages, yield and quality were all monitored. With seasonal conditions providing a soft finish, the trial was remarkably successful.
Barley did exceptionally well, returning yields as high as 8t/h in the Esperance region and more than 5t/ha further south-west towards Albany. Wheat did not lag too far behind, yielding at more than 5t/ha and around Albany wheat out-performed barley. It was also noted that a split nitrogen application regime (especially in wetter conditions) might further boost yield and grain protein.
Due to grower interest in understanding what happens to yield and quality in a more typical season – with a more-characteristic dry and hot finish – the project is being extended in 2023. Overall, the trial demonstrates the adaptability of cereal cropping systems in this region and generates confidence in late sowing decisions where waterlogging has occurred.
More information: Elizabeth von Perger, [email protected]
Long coleoptile wheat
By Mike Lamond, SLR Agriculture
Increases in wheat coleoptile length have proven possible using the novel Rht18/Rht13 dwarfing genes. They allow an increase in coleoptile lengths from 40 to 60 millimetres in varieties such as Mace; and Scepter; to lengths of 120 to 140mm. This increased length opens the way to explore earlier sowing dates, even in the absence of a break, by chasing moisture deeper in the soil profile.
Scoping studies have been undertaken in WA to assess various aspects of including long-coleoptile wheats in WA farming systems. Six field trials were undertaken in 2021 followed by seven trials in 2022.
These studies found that the extra coleoptile length allows for greater sowing depths, which translates into numerous benefits. There are opportunities to chase moisture lower in the soil profile, especially during dry sowing early in the season. The long coleoptile genes also translated into increased:
- weed competition; and
- avoidance of Rhizoctonia.
The genes also increased plant establishment rates and improved emergence:
- through warm soils;
- in ameliorated soils; and
- through furrow-fill from wind and rain events.
Overall, long-coleoptile wheat lines were found to have the potential to provide greater control around sowing windows. These characteristics could prove especially advantageous in the face of climate variability and a shift in main-season breaks.
Additional information and resources about integrating long coleoptile wheat in the west region have generated and are available on the GRDC website.
More information: Mike Lamond, [email protected]
By Chris O’Callaghan, The Liebe Group
Early sowing trial of canola in WA. Photo: The Liebe Group
In early 2022 in WA, weather forecasts detected the formation of a tropical cyclone system (Charlotte) with the ability to deliver high March rainfall.
Growers on the research and development committee at the Liebe Group saw the incoming rain as an opportunity to close an information gap around how early canola can be sown in the northern area of Kwinana West.
Within two weeks of the forecasts, the Liebe Group had finalised protocols and received investment from GRDC through the NGN to run the early sown canola trials. The cyclone system delivered 114mm in the Dalwallinu region between 26 and 30 March. These weather events could become more common as changes to climate see more late tropical low systems coming further south and providing a non-traditional season break.
A small plot trial was implemented in Xantippe to test whether non-conventional rain events present an early sowing opportunity. The trial compared yields from plots sown on 5 April versus 6 May. The following varieties were used:
- Emu: an early maturing TruFlex® hybrid;
- Battalion: an early maturing hybrid with both TruFlex® and Clearfield® technologies;
- InVigor® R4022P: an early-mid maturing TruFlex® hybrid;
- Invigor® R4520P: an early-mid maturing TruFlex® hybrid; and
- GT53: a mid-maturing TruFlex® hybrid.
Yield data found that sowing any variety in early April outperformed any variety sown in early May. Pioneer® 44Y27 had the highest yield at 3.02t/ha. This was nearly double the yield achieved by this variety when sown a month later (1.8t/ha). In fact, a near-doubling in yield was observed for all varieties sown early.
There were no yield differences among varieties sown at the later date.
An economic analysis has been performed and more information is available through the Liebe Group, which is repeating the trial in 2023 and will be conducting field days at Boyd Carter’s Jibberding property.
The 2023 trial also took advantage of an early break, but one that delivered less rainfall, and will test risks associated with early sown canola, given that 2023 is unlikely to deliver the soft finish seen in 2022.
Additional information is available on the GRDC website.
More information: Chris O’Callaghan, [email protected]
Barley and wheat
By Tom Price and Nick Poole, Field Applied Research Australia
In western areas of NSW, when soil moisture allows, there are opportunities to sow early in April. However, the available range of winter barley and winter wheat varieties often experience heat and water stress in their critical growth period that reduces yields. Early sown, main-season barley and wheat types – typically spring germplasm – experience a high risk of frost damage.
In contrast, longer-season, faster-finishing cultivars offer opportunities to exploit early rain events, with a better balance of heat and frost risk.
With a view to exploiting these opportunities, a project was launched through the NGN to define the advantages and disadvantages of longer-season spring varieties compared with winter and early spring types. This approach aims at better water-to-grain conversion when faced with early sowing opportunities in typically low rainfall settings.
The project runs from 2022–24 and involves replicated field trials located at sites in Daysdale (hosted by Peter Hanrahan, managed by FAR Australia) and Beelbangera (hosted by Barry Haskins, managed by AgGrow Agronomy) near Griffith, NSW.
These trials are testing early sowing of long-season cereals and their management requirements. A mid-April sowing date will be compared with a mid-May planting in regions where lower rainfall and higher temperatures typically influence productivity.
The project is led by FAR Australia in collaboration with AgGrow Agronomy & Research.
Key measures being compared between the two sowing dates are:
- crop structure;
- dry matter production; and
- grain yield and quality.
The barley varieties included in the trial are:
- Newton (winter barley);
- RGT Planet (spring barley);
- Beast (spring barley); and
- Maximus CL (spring barley).
The wheat cultivars are:
- RGT Waugh (slow winter);
- Anapurn (slow winter);
- RGT Accroc (slow mid-winter);
- Illabo (medium winter);
- Mowhawk (quick winter);
- Longsword (quick winter);
- Stockade (very slow spring);
- LongReach Nighthawk (slow spring);
- LongReach Raider (slow spring);
- Rockstar (slow spring);
- LongReach Lancer (medium spring);
- Scepter (quick mid-spring);
- Sunmaster (quick mid-spring);
- Vixen (quick spring);
- Boree (mid spring) by FAR only; and
- Zanzibar (mid-late spring) by FAR only.
The trial design also allows an exploration on how best to manage the biomass of early sown wheat cultivars and how to adapt them to a lower-rainfall, higher-temperature region where too much biomass has the potential to negatively impact yield. This is explored through the use of seed rates and defoliation of early sown canopies. Field days for these trials are typically held in September.
Additional information is available on the GRDC website.
More information: Tom Price, [email protected]