Canola — understanding what varieties to plant and when to plant them

Take home messages

• HyTTec® Trophy, InVigor T® 4510, Pioneer® 43Y92, Pioneer® 44Y90 and Nuseed Quartz all performed well in SA National Variety Trial (NVT) canola trials in 2017.
• Time of sowing experiments demonstrated benefits from matching sowing date to variety phenology with canola.
• Optimal start of flowering time for canola provides a target range for flowering to start within to minimise frost, heat and water stress and maximise yield for a particular environment.
• Once the development triggers and phenology for a variety are understood, an optimal sowing date for canola can be derived to match the optimal flowering time for specific localities.

Background

The selection of the most suitable canola variety for a particular situation needs consideration of maturity, along with timing of sowing opportunity, herbicide tolerance, blackleg resistance, and relative yield.

Canola variety evaluation in SA occurs at 12 sites that form part of the NVT network (DAS00163). Evaluation of triazine tolerant (TT) and imidazolinone (Imi) tolerant lines, in separate trials, occurs at each of the 12 sites, and evaluation of conventional lines occurs at seven sites.

Research to better understand the yield drivers of canola in eastern Australia commenced in 2014 and has continued ever since, with the aim to improve canola profitability through gaining a better understanding of how phenology and environment can be best matched to improve canola yields. This research is targeted at low to medium rainfall zones of eastern and southern Australian cropping regions and is a collaboration between CSIRO, NSW DPI and GRDC, in partnership with SARDI, Charles Sturt University (CSU), Mallee Sustainable Farming (MSF) and Birchip Cropping Group (BCG) (CSP00187). The project links closely with similar GRDC supported projects in Western Australia (WA) and high rainfall zones (HRZ).

2017 season

The break to the 2017 season was variable and quite patchy across much of SA. Where it occurred before May, it was followed by a lengthy dry and well below average rainfall period through much of May and June. This resulted in poor canola establishment in some areas, particularly on Eyre Peninsula (EP) and parts of the Mallee.

Growers on Lower EP reported that, despite poor establishment and the delayed start to the season, dry sown canola crops were still profitable. However, on Upper EP, there were many instances of canola crops failing.

Elsewhere in the state, parts of the South East experienced waterlogging and several frost events negatively impacted canola crops in the Mallee. Otherwise canola yields were in line or slightly above recent averages.

SA NVT canola 2017 results

In 2017, NVT canola trials in SA yielded from 1.2t/ha at Lameroo to 3.29t/ha at Arthurton (Table 1). The top yielding triazine tolerant (TT) varieties were newly released Nuseed variety, HyTTec® Trophy, as well as Bayer’s InVigor® T 4510, both hybrid varieties. Open pollinated TT varieties yielded significantly less than the top performing hybrids at all SA sites in 2017.

Highest yielding entries in 2017 Imi tolerant canola trials were newly released 43Y92 CL and 44Y90 CL, both from Pioneer Brand Seeds. Conventional trials saw the newly released Nuseed Quartz as the top performing variety in 2017.

All three 2017 EP canola trials were abandoned due to the late break to the season. The trial site at Bordertown was also abandoned.

Table 1. 2017 SA NVT canola yields (expressed as % of site mean yield).

Variety x time of sowing experiments (Optimised Canola Project; CSP00187)

In 2017, experiments were established at Yeelanna (Lower Eyre Peninsula (EP)), Hart (Mid-North), and Lameroo (Mallee) aimed at discovering the best match of sowing time with variety in each environment.

Results from the experiment at Yeelanna (Table 2), where canola was established using irrigation on 14 April and 8 May, found that the highest yielding treatments were the quicker maturing varieties Diamond and 44Y90 CL, when sown on 8 May, yielding similarly to the longer season variety, Archer sown on 14 April.

The trials at Hart and Lameroo found that Diamond and 44Y90 CL were again the highest yielding varieties, with ATR Stingray also performing well at Lameroo, when sown on the first sowing date. The first time of sowing in both of these experiments was later (21 and 27 April) than at Yeelanna. There was a consistent yield penalty for delaying sowing beyond the first time of sowing at both Hart and Lameroo.

Table 2. Summary of yields from canola time of sowing x variety experiments conducted at Yeelanna (Lower EP), Hart (Mid North) and Lameroo (Mallee) in 2017.

*bird damage

** established using dripper hose irrigation

***including irrigation

Similar to previous years, these experiments concluded that yield for each variety is maximised when sowing time matches an optimal flowering window, where frost, heat and water stress are all minimised.

Optimum start of flowering

Following four years of field experiments and considerable effort to improve simulated modelling in APSIM®, the Optimised Canola Profitability project has been able to identify the optimum start of flowering date* for canola so that yield is maximised and frost, heat and water stress are all minimised. This information has been used in conjunction with historical meteorological records to produce an optimum start of flowering date (and acceptable range – in days) for a number of SA localities (Table 3).

Table 3. Optimum start of flowering date for 13 localities in SA.(Modelling conducted by Julianne Lilley, CSIRO, Canberra).

*start of flowering is defined as when 50% of plants have one open flower.

This information can now be used to extrapolate when a particular canola variety should be sown to maximise yield and minimise environmental stresses (based on historical information) for a specific locality. However, this requires an understanding of the development triggers and phenology for each variety, particularly in early sowing situations. Table 4 provides some of this information based on measurements and observations by the Optimised Canola Profitability project across south eastern Australia over recent years.

Table 4. Proposed ‘phenology ratings’ of canola varieties compared with commercial ‘maturity’ ratings.

Twenty two canola varieties (above) were included in the Optimised Canola Project from 2014 to 2016. Phenology differences between varieties were a major yield determinant in the project, however phenology did not relate to commercial maturity ratings for early sowing. The project committee is encouraging industry to adopt more accurate phenology terminology as described above to guide sowing date decisions and target the optimal start of flowering period.

Other or newer varieties are available that may also be suited to early sowing, including those indicated above (*).

Conclusion

HyTTec® Trophy, InVigor® T 4510, Pioneer® 43Y92, Pioneer® 44Y90 and Nuseed Quartz all performed well in SA NVT trials in 2017.

Time of sowing experiments demonstrated benefits from matching sowing date to variety phenology. Optimal start of flowering time provides a target range for flowering to start within to minimise frost, heat and water stress and maximise yield for a particular environment. Once the development triggers and phenology for a variety are understood, an optimal sowing date can be derived to match the optimal flowering time.

Useful resources

2018 Sowing Guide SA

National Variety Trials

GrowNotes™ - GRDC -  Southern Canola

10 Tips Early Sown Canola

Acknowledgements

The research undertaken as part of this project is made possible by the significant contributions of growers through both trial cooperation and the support of the GRDC — the authors would like to thank them for their continued support.

This work is a component of the 'Optimised Canola Profitability' project (CSP00187), a collaboration between NSW DPI, CSIRO and GRDC in partnership with SARDI, CSU, MSF and BCG.

Thank you to the numerous SA growers and Hart Field Site group for making their land available for the field trials and to the technical officers of the SARDI New Variety Agronomy group for their assistance in conducting the field trials.

Contact details

Andrew Ware    
1 Hindmarsh St, Port Lincoln SA 5606
0427 884 272
andrew.ware@sa.gov.au