Optimised canola profitability project (2016 results)

Author: Rohan Brill(1), Rick Graham(1), Ian Menz(1), Leigh Jenkins(1), Don McCaffery(1), Colin McMaster(1), John Kirkegaard(2) and Julianne Lilley(2) | Date: 10 Mar 2017

1NSW DPI
2CSIRO Canberra

Take home messages

  • Early sowing of canola exposes the inherent phenological differences between commercial canola varieties – understand your optimum flowering window, and select varieties with correct genetics to flower in this period!
  • In 2016 (with the exception of the most northern site Breeza) slower developing varieties maintained relatively consistent yield across sowing dates.
  • Early sowing of faster developing varieties increases exposure to fungal diseases and reduced biomass and yield potential.
  • There was a strong relationship between final biomass and grain yield
  • Certain varieties convert biomass more efficiently into grain yield (higher HI)
  • 2016 reinforced the need to consider adequate nitrogen so as to optimise yield potential
  • Aim to plant canola in paddocks with a high starting nitrogen availability or be prepared to feed it
  • Seed colour change (SCC) should be measured on a whole plant basis not solely the main stem, as seed development is being underestimated impacting yield and quality

Introduction

Optimised Canola Profitability (OCP) is a collaborative project between NSW DPI, CSIRO, SARDI and GRDC. A strong focus of the research to date has been on investigating the interactions between sowing date and variety choice of canola as it relates to phenology, biomass accumulation, grain yield and oil concentration. Variety by sowing date experiments were planted across the Northern and Southern GRDC regions in 2016, from the Darling Downs in SE Queensland, Canowindra on the central-west slopes of NSW, Horsham in the Wimmera region of Victoria and west to the Eyre Peninsula in South Australia. This paper presents an overview of results from across NSW including nitrogen trials.

Phenology of commercial cultivars - 2016

An understanding of varietal phenology as well as characterisation of a particular environment enables variety choice and sowing date decisions to target optimum flowering time to reduce frost, heat and moisture stress risks during reproductive development. Radiation also influences the optimum flowering window due to the positive relationship between intercepted radiation and seed number. Record low radiation levels in 2016 together with high rainfall, warm winter temperatures and low spring temperatures made this an important issue.

To determine the varietal response to sowing date, a diverse set of varieties was sown in experiments at a range of locations in 2016 (Table 2). This paper reports on phenology and grain yield results from five sites – Wagga Wagga (eastern Riverina, NSW), Ganmain (north-eastern Riverina, NSW), Condobolin (CW Plains NSW), Trangie (CW Plains NSW) and Breeza (Liverpool Plains, NSW). Common across these sites in 2016 was well above average (or near record) rainfall, cool spring temperatures (no major heat events) and very low incoming solar radiation during winter and spring (lowest on record for the period from May to October).

Table 1. Location, fallow rainfall (November to March), in-crop rainfall (April to October), soil nitrogen at sowing and nitrogen applied to five canola experimental sites across NSW in 2016.

Region

Nov 15-Mar 16 Rainfall

Apr 16-Oct 16 Rainfall*

Available N (sowing)

Applied N

Wagga

Riverina

243 mm

625 mm

133 kg/ha

200 kg/ha

Ganmain

Riverina

233 mm

530 mm

129 kg/ha

0-200 kg/ha

Condobolin

CW Plains

198 mm

498 mm

253 kg/ha

0-125 kg/ha

Trangie

CW Plains

251 mm

530 mm

NA

NA

Breeza

Liverpool Plains

218 mm

426 mm

106 kg/ha

167 kg/ha

* To ensure timely establishment, early sowing experiments were irrigated with small amounts of water.

Archer was the slowest variety to flower (determined as 50% of plants with one open flower) from early sowing at each site, with the most consistent flowering date across sowing dates (Table 2). At Wagga Wagga, there was 19 days difference in flowering date of Archer between sowing on 31 March and 29 April. In contrast, there was 59 days difference in flowering date for the same sowing dates of Nuseed Diamond. The ability of Archer to flower in a tight flowering window regardless of sowing date means that it has a wide and flexible sowing window. Other varieties with a similar (but lesser) ability to regulate their flowering window at earlier sowings (early April) include ATR Wahoo, Pioneer 45Y25 RR, Hyola 725RT and Hyola 600RR. Varieties that are generally very quick to flower from early sowing include Nuseed Diamond, ATR Stingray, IH30RR and Hyola 575CL.

Table 2. Date of flowering (50% of plants with one open flower) of canola varieties sown at two or three sowing dates at five sites across NSW in 2016.

Wagga Wagga

Ganmain

Condobolin

Trangie

Breeza

31-Mar

13-Apr

29-Apr

7-Apr

21-Apr

6-Apr

20-Apr

1-Apr

14-Apr

17-May

13-Apr

16-May

17-Jun

Diamond

6-Jun

12-Jul

4-Aug

-

-

-

-

-

-

-

-

-

-

ATR Stingray

10-Jun

12-Jul

2-Aug

9-Jul

28-Jul

3-Jul

24-Jul

-

-

-

-

-

-

IH30 RR

16-Jun

20-Jul

8-Aug

-

-

-

-

-

-

-

-

-

-

Hyola 575CL

16-Jun

15-Jul

18-Aug

-

-

-

-

7-Jun

10-Jul

19-Aug

16-Jul

26-Aug

12-Sep

44Y89 CL

23-Jun

22-Jul

18-Aug

22-Jul

11-Aug

12-Jul

2-Aug

15-Jun

13-Jul

9-Aug

22-Jul

25-Aug

12-Sep

43C80 CL

-

-

-

-

-

-

-

25-Jun

19-Jul

*

27-Jul

22-Aug

6-Sep

ATR Bonito

-

-

-

-

-

-

-

-

-

-

-

-

-

ATR Gem

8-Jul

26-Jul

18-Aug

-

-

-

-

-

-

-

-

-

-

45Y86 CL

-

-

-

-

-

-

-

12-Jul

26-Jul

*

25-Jul

22-Aug

16-Sep

45Y88 CL

12-Jul

4-Aug

29-Aug

-

-

-

-

3-Jul

21-Jul

28-Aug

30-Jul

30-Aug

15-Sep

Hyola 559TT

15-Jul

1-Aug

22-Aug

-

-

-

-

-

-

-

-

-

-

GT50 RR

15-Jul

1-Aug

18-Aug

-

-

-

-

-

-

-

-

-

-

Hyola 600RR

22-Jul

2-Aug

29-Aug

-

-

-

-

-

-

-

-

-

-

Hyola 725RT

26-Jul

8-Aug

31-Aug

-

-

-

-

-

-

-

-

-

-

45Y25 RR

-

-

-

-

-

-

-

-

-

-

-

-

-

ATR Wahoo

-

-

-

18-Aug

25-Aug

5-Aug

12-Aug

-

-

-

-

-

-

Archer

12-Aug

18-Aug

31-Aug

23-Aug

30-Aug

7-Aug

15-Aug

29-Jul

5-Aug

31-Aug

11-Aug

5-Sep

22-Sep

*At Trangie for the 17 May sowing date, both 45Y86 CL and 43C80 CL had poor establishment so were excluded from the analysis.

When should canola flower?

Preliminary research in 2016 suggests that the critical stage for yield potential of canola is between 100 and 500 degree days (°C.days), after the commencement of flowering. Stress that reduces growth during this period has the biggest impact on grain yield.

The critical growth period needs to coincide with the optimal environmental conditions (critical flowering windows) that is, when the risk of frost, heat and moisture stress are minimised and yet there is sufficient radiation to provide energy for growth. The critical flowering window for canola across a range of environments is being characterised as part of the OCP project.

Sowing date and grain yield – 2016

At Breeza, there was no interaction between variety and sowing date, meaning that all varieties followed a similar trend across sowing dates for yield. Abnormally, the last sowing date (17 June) was the highest yielding at 4.4 t/ha compared to 3.3 t/ha for the first sowing date (13 April) and 4.0 t/ha for the second sowing date (16 May). This may have been a reflection of season, which was atypical with a mild winter and spring and excellent growing season rainfall, allowing growth and grain development well into spring. The yield potential of the first sowing date was also impacted by poorer plant establishment compared to the other two sow dates, whilst the second sow date was effected by waterlogged conditions post-sowing. There were however, differences between varieties with Pioneer 44Y89 (CL) the highest yielding variety averaged across sow dates.

At Trangie, the four varieties that were sown at each of the three sowing dates all had their highest grain yield from either the first (1 April) or second sowing date (14 April).

At Wagga Wagga, long season varieties such as Archer, GT50 RR and Hyola 600RR maintained consistent grain yield across sowing dates (Table 3), and GT50 RR was the only variety to yield above 4 t/ha from each sowing date. The highest individual treatment yield was Nuseed Diamond sown on 29 April, yielding 4.8 t/ha. Fast developing varieties such as Nuseed Diamond, ATR Stingray, Pioneer 44Y89 (CL) and Hyola 575CL yielded less from early sowing, partly because flowering occurred too early to maximise biomass and seed number.

In addition to the reduced biomass from early sowing, Nuseed Diamond and ATR Stingray had increased disease infection (despite multiple applications of fungicide). The very early flowering (June) of these varieties exposed them to infection events all through winter, with the grain yield of Nuseed Diamond reduced by Sclerotinia (approx. 25% of plants infected) and the grain yield of ATR Stingray reduced by upper canopy blackleg infection (greater than 50% of pods infected).

Table 3. Grain yield of 16 canola varieties sown at two or three sowing dates across NSW in 2016-

Wagga Wagga

Ganmain1

Condobolin1

Trangie

Breeza2

31-Mar

13-Apr

29-Apr

7-Apr

21-Apr

6-Apr

20-Apr

1-Apr

14-Apr

17-May

13-Apr

16-May

17-Jun

Diamond

3.1

4.4

4.8

-

-

-

-

-

-

-

 

 

 

ATR Stingray

2.6

3.4

3.9

2.4

2.4

2.8

3.5

-

-

-

IH30 RR

3.4

3.1

3.9

-

-

-

-

-

-

-

Hyola 575CL

3.5

3.8

3.3

-

-

-

-

3.1

3.3

2.6

44Y89 CL

3.4

4.2

4.3

3.2

3.1

3.5

4.2

3.8

3.9

3.0

43C80 CL

-

-

-

-

-

-

-

3.5

3.5

*

ATR Bonito

-

-

-

-

-

-

-

-

-

-

ATR Gem

3.5

3.8

3.3

-

-

-

-

-

-

-

45Y86 CL

-

-

-

-

-

-

-

3.3

3.1

*

3.3

4.0

4.4

45Y88 CL

3.7

3.8

4.1

-

-

-

-

3.9

3.1

3.4

Hyola 559TT

3.4

3.8

3.8

-

-

-

-

-

-

-

GT50 RR

4.1

4.1

4.2

-

-

-

-

-

-

-

Hyola 600RR

3.9

4.1

4.4

-

-

-

-

-

-

-

Hyola 725RT

3.0

4.0

3.5

-

-

-

-

-

-

-

45Y25 RR

-

-

-

-

-

-

-

-

-

ATR Wahoo

-

-

-

2.2

2.5

3.4

3.6

-

-

-

Archer

4.0

3.6

4.1

2.9

2.8

4.3

4.0

3.5

3.2

3.2

l.s.d. (P=0.05)

0.46

0.36

0.39

0.66

0.38

*43C80 CL and 45Y86 CL had poor establishment from the 17 May sowing date at Trangie so were excluded from the analysis.
1Nitrogen treatments were included at Finley, Ganmain and Condobolin. Yield results are reported for the highest N rate in each experiment.
2At Breeza, the interaction between variety and sowing date was not significant so only the effect of sowing date and associated l.s.d. is reported.

At Ganmain there was no effect of sowing date on grain yield, but the hybrid Clearfield varieties Pioneer 44Y89 CL and Archer were both significantly higher yielding than the open-pollinated TT varieties, ATR Stingray and ATR Wahoo.

At Condobolin, the yield of the fast developing varieties ATR Stingray and Pioneer 44Y89 (CL) was reduced by early sowing (disease level not significant), but the grain yield of Archer and ATR Wahoo was consistent across sowing dates. Comparing varieties with similar phenology (and similar to the finding at Ganmain), Pioneer 44Y89 (CL) was higher yielding than ATR Stingray and Archer was higher yielding than ATR Wahoo.

Oil concentration

At Breeza there was no significant difference between sowing dates, for oil concentration averaged across varieties. With oil concentrations of 41.7% for the early sowing date (April 13), 43.3% for the 16 May and 41.9% late sow date of 17 June. In contrast at Wagga Wagga there was an increase in oil concentration with delayed sowing (averaged across varieties). Oil concentration was 42.9% from 31 March sowing, 44.6% from 13 April sowing and 45.7% from 29 April sowing. Similarly, at Trangie, the 17 May sowing date had the highest oil concentration (44.1%) compared with the 1 April and 14 April sowing dates (41.7% and 41.3% respectively).

The increased oil concentration with delayed sowing at Wagga Wagga and Trangie, was considered unusual as in most seasons, it is expected that delayed sowing reduces oil concentration as the crop is exposed to increased heat and moisture stress during reproductive stages.

Nitrogen response

At the Breeza, Ganmain and a separate experimental site at Finley, nitrogen ‘indicator’ experiments were sown to determine the responsiveness of the individual sites. Rates of N up to 1000 kg/ha were included, with the N broadcast as urea in front of the seeder at Ganmain and Finley and predrilled at Breeza. Despite the physical separation of N, rates of 500 kg/ha and above generally reduced establishment, with only rates up to 300 kg/ha reported here.

At Finley (starting soil N 108 kg/ha) and Ganmain (starting soil N 129 kg/ha), there were positive grain yield responses for N rates up to 300 kg/ha (652 kg/ha urea) (Figure 1). At Breeza (starting soil N 106 kg/ha) there was likewise, an increasing trend for grain yield, to increasing N rates. Yield increasing from 3.24 t/ha for nil additional N, to 4.59 t/ha for 100 kg N/ha, a 29% increase in grain yield (Figure 2). Consistent with past research, increasing the rate of N reduced oil concentration at Finley (Ganmain data not available), with oil declining from 44.4% with nil N to 40.7% with 300 kg N/ha. The same trend of increasing N rate and decline oil concentration was also observed at Breeza, oil declining from 44.5% for nil N, down to 42.0% with 300 kg N/ha (Figure 2). Despite this lower oil concentration with the high N rate at Finley, the total amount of oil produced was greatly increased with the application of N, from 1.11 t/ha (nil N) to 1.45 t/ha (300 kg/ha N).

From these results, it is recommended that canola growers look to apply more N to their crops in order to increase grain yield potential, given that similar results have been widely observed in previous seasons. The medium to long term strategy should be to target paddocks with relatively high soil N values. Growers who planted pulses in 2016 should therefore consider planting canola in these paddocks in 2017, as they would more likely have more plant available water and N in their soil profile than cereal crops.

Figure 1. Effect of nitrogen (N) rate on grain yield of canola at Ganmain and Finley; and on oil concentration at Finley only in 2016.

Figure 1. Effect of nitrogen (N) rate on grain yield of canola at Ganmain and Finley; and on oil concentration at Finley only in 2016.

Figure 2. Effect of nitrogen (N) rate on grain yield (t/ha) and oil concentration (%) of canola at Breeza in 2016.

Figure 2. Effect of nitrogen (N) rate on grain yield (t/ha) and oil concentration (%) of canola at Breeza in 2016.

Importance of timing of biomass accumulation

In the previous two years (2014-2015) of experiments, data showed that biomass at maturity had a positive linear relationship with grain yield. This was again demonstrated in 2016 (Figure 3); however when growth was divided into that which occurred pre-flowering (flowering biomass) and post-flowering, data shows that post-flowering growth had a greater influence on grain yield than pre-flowering growth (data presented for southern and central NSW sites only, Wagga Wagga, Finley, Ganmain and Condobolin).

Only at the waterlogged site at Ganmain was there a relationship between flowering biomass and grain yield. At Ganmain there was a linear relationship between biomass at flowering and grain yield but only for biomass levels below 5 t/ha.

Management tactics that optimise post-flowering growth will be further investigated in future years of research, but are likely to include timing of flowering, nitrogen management and variety choice.

 Figure 3. Relationship between grain yield and biomass at flowering, growth post-flowering and biomass at maturity in canola trials at Wagga Wagga (×), Finley (▪), Ganmain (▲) and Condobolin (◊) in 2016.

Figure 3. Relationship between grain yield and biomass at flowering, growth post-flowering and biomass at maturity in canola trials at Wagga Wagga (×), Finley (▪), Ganmain () and Condobolin (◊) in 2016.

Harvest index and biomass accumultion

Some varieties can achieve a higher grain yield per unit of total biomass grown, referred to as harvest index (HI). At Wagga Wagga in 2016, ATR Stingray had the highest harvest index but had the lowest biomass at maturity, so its grain yield was at the lower end of the varieties (averaged across sowing dates). Nuseed Diamond stands out as a variety that grows at least moderate levels of biomass but also has a high conversion rate of that biomass into grain. Nuseed Diamond grew a similar amount of total biomass as Pioneer 45Y88 CL, Pioneer 44Y89 CL, Hyola 725 RT and GT50 RR but had a 17%, 10%, 21% and 10% higher harvest index, respectively over these varieties. The ability of some varieties to grow good quantities of biomass and then convert this biomass more efficiently into grain yield will be a focus of future research.

Harvest management

Industry guidelines for canola windrowing recommend that optimum cutting time occurs when 40-60% of seeds on the primary stem have changed colour from green to red, brown or black. Similarly, chemical desiccation guidelines are based on seed colour change (SCC). Research undertaken at Trangie and Tamworth has highlighted the importance of correct windrow timing and the need to accurately determine SCC. Windrowing, earlier than the current recommendations (i.e. <40% SCC), resulted in significant reductions in both grain yield and oil concentration at both Tamworth and Trangie. Importantly, at Trangie in 2015 there was a yield reduction for both Hyola 575 CL and Pioneer 44Y89 (CL) when the actual SCC of the main stems was >50% SCC. It was observed from the partitioning of seed from pods from the stem and branches that SCC of branches was slower to mature than that of the stems. When considering the breakdown of the yield components of stem versus branches, stems also only contributed < 30% of the grain yield. This data suggests that SCC should be measured on a whole plant basis, not solely on the main stem, particularly where branches are likely to contribute a large proportion of potential yield. It would appear that by relying solely on the stem to estimate SCC that overall seed development is being underestimated and therefore potentially negatively impacting yield and quality parameters. Additional data from 2016, will be presented at the GRDC Update.

Conclusion

The OCP project has demonstrated that there are some varieties that have a wide planting window, allowing sowing opportunities to be captured when they arise, that can often match the yields of later-sown varieties. Such varieties may not always be the highest yielding but do offer greater flexibility to the farming system. In the warmer northern environments however, where terminal drought and heat events prevents longer season varieties from flowering in the optimum flowering window, mid to fast maturating varieties offer a safer risk management option. In contrast these faster developing variety options should only be planted late in the sowing window, to avoid reduced grain yield potential and increased disease risk.

The 2016 season again reinforced the importance of adequate nitrogen nutrition for canola. Point out that the best variety choice and sowing date option, without appropriate nitrogen management, is a lost opportunity in terms of yield potential. Growers need to ensure that approximately 80 kg/ha of nitrogen is available to the crop per tonne of targeted grain yield. With declining levels of soil fertility generally this means nitrogen requirements are being met increasingly by fertiliser rather than soil reserves. Targeting plant canola at high N situations will greatly reduce the risk associated with growing canola. Finally, harvest management experiments looking at SCC, have shown that by relying solely on the stem to determine SCC, that overall seed development is being underestimated, potentially negatively impacting yield and quality parameters.

Acknowledgements

Thanks to all technical staff for their assistance with these experiments, including Rod Bambach, Stephen Morphett, Jan Hosking, Scott Richards, Nick Hill, Sharni Hands, Warren Bartlett, Danielle Malcolm, Jess Simpson and Daryl Reardon.

Thanks also to trial co-operators, Ben Beck at Wagga Wagga and Dennis and Dianne Brill at Ganmain and Scott Goodworth at the LPFS, Breeza.

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 author would like to thank them for their continued support.

Contact details

Rohan Brill
Wagga Wagga Agricultural Institute
Ph: 02 6938 1989
Email: rohan.brill@dpi.nsw.gov.au

Rick Graham
NSW DPI, Tamworth
Ph: 0428 264971
Email: rick.graham@dpi.nsw.gov.au

Varieties displaying this symbol beside them are protected under the Plant Breeders Rights Act 1994.

GRDC Project code: CSP00187 & DAN00198