1. Increasing whole-farm wheat yield and reducing risk through early sowing SUSTAINABLE AGRICULTURE FLAGSHIP James Hunt, Neil Fettell, Jon Midwood, Paul Breust, Brad Rheinheimer, Annieka Paridaen 27 February 2013

2. Take-home messages Know the optimal flowering date in your location and how to achieve it with different varieties from a broad range of sowing dates. Slow maturing varieties sown early have a yield advantage over mid-fast varieties (average 0.8 t/ha) Including a slow maturing variety in a cropping program (opens sowing window to early April) increases average farm wheat yield by 13-47% Yield penalty from sowing later than optimal always greater than sowing earlier than optimal even in frosty springs Highest yields in time-of-sowing trials have ~5% frost damage Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

3. Recent research on south-east Australian rainfall Rainfall reductions over Southern Hemisphere semi-arid regions: the role of subtropical dry zone expansion Wenju Cai, Tim Cowan Marcus Thatcher - CSIRO Marine and Atmospheric Research Published Nature Scientific Reports - October 2012 Last 17 years of dry autumns due to southward shift in sub-tropical ridge Southeast Australia autumn rainfall reduction: a climate-change- induced pole-ward shift of ocean-atmosphere circulation Wenju Cai, Tim Cowan - CSIRO Marine and Atmospheric Research Published Journal of Climate January 2013 Not connected to southern annular mode Pole-ward shift in circulation partly attributable to climate change Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

4. Temora moves to Macquarie Marshes!!!! Subtropical ridge has moved 400 km south in April-May April-May rainfall trend since 1951 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

5. Old Junee Apr-May rainfall Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

6. Old Junee Feb-March rainfall Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

7. What are we going to do about it? Conserve as much summer rain as possible – spray summer weeds See results of GRDC National WUE Initiative 2008-2012 Dry sow as much area as possible with mid-fast varieties As much area established as possible when break comes Plant winter wheats from late Feb-late April when moisture available Plant slow maturing spring wheats from early-late April when moisture available Learn how to moisture seek Learn Spanish and polo and move to Argentina Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

8. Winter & spring wheats Winter wheats have a vernalisation or cold requirement before floral- initiation (~Z30) begins ~4-11°C. Very flexible sowing window – 2 months vs. 2 weeks Our spring wheats do not have vernalisation, but development is usually controlled by a photoperiod or day-length requirement Eaglehawk, Bolac > Bounty, Gregory > Gauntlet, Suntop > Lincoln, Axe Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Emergence – Z30 Z30-Z69 Z69-maturity Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Emergence – Z30 Z30-Z69 Z69-maturity Winter wheat Mid maturing spring wheat Emergence – Z30 Z30-Z69 Z69-maturity Slow maturing spring wheat

9. Sowing and flowering dates Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Optimal flowering window Wedgetail sowing window (winter wheat) Eaglehawk sowing window (slow maturing spring wheat) Janz sowing window (early- mid maturing spring wheat

10. Why slow maturing wheats sown early? Allow earlier sowing to take advantage of stored soil water without frost risk associated with mid-fast varieties Widen sowing window in face of decreasing sowing opportunities and larger farm sizes Subtropical ridge has moved 400 km south in April- May (Temora = Nyngan) Reduce yield losses from water-logging Dual purpose option Long season wheats sown early should in theory; Use more water (deeper roots, longer growing season) Transpire a greater proportion of water Transpire more efficiently (more growing during lower VPD) Grow more dry-matter & have higher yield potential But they dont yield more than short-season wheats sown late Riffkin et al. 2003 rain-fed wheat at Hamilton Stapper & Fischer 1990 irrigated what at Griffith Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

11. Pre-experimental modelling Three environments (high, medium & low rainfall) Lake Bolac Temora Condobolin Use modelling to identify optimal flowering window APSIM frost & heat multiplier (after Farre et al. 2010) Minimum T 0 < 2°C Z60-69 = 10% yield loss Minimum T -2 < 0°C Z60-75 = 20% yield loss Minimum T < -2°C Z60-79 = 90% yield loss Use ToS experiments and modelling calculate how to get cultivars of different maturity to flower in correct window Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

12. Lake Bolac Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

13. Temora Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

14. Condobolin Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

15. Sowing times consistent across environments Maturity groupVariety (site)Optimal sowing date Very slowForrest (LB) Eaglehawk (T, C) 15 April SlowBolac (LB, T, C)25 April MidDerrimut (LB, T) Gregory (T, C) 5 May FastLincoln (LB, T, C)15 May Very fastAxe (C)20 May Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

16. Improving WUE of early sown wheat Management to improve harvest index Very low plant density Plant growth regulators Maturity classSowing date 15 April27 April9 May19 May Very slow (Eaglehawk) 40 pl/m² +PGR 40 pl/m² -PGR 100 pl/m² +PGR 100 pl/m² -PGR Slow (Bolac) 100 pl/m² -PGR40 pl/m² +PGR 40 pl/m² -PGR 100 pl/m² +PGR 100 pl/m² -PGR Mid (Gregory) 100 pl/m² -PGR 40 pl/m² +PGR 40 pl/m² -PGR 100 pl/m² +PGR 100 pl/m² -PGR Mid-fast (Lincoln) 100 pl/m² -PGR 40 pl/m² +PGR 40 pl/m² -PGR 100 pl/m² +PGR 100 pl/m² -PGR Current practice New practice Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

17. Temora 5 October 2011

18. Improving WUE of early sown wheat Temora 2011 - very slow maturing variety sown early and managed for high HI yields 0.8- 0.9 t/ha more than current practice 207 mm GSR Slow varieties better grain quality (APH) - $35/t premium Net benefit = $413/ha with less initial expenditure Grain yield (t/ha)Harvest index Variety & sow date40 plants/m²100 plants/m²40 plants/m²100 plants/m² Eaglehawk (15 April)6.36.00.410.39 Bolac (27 April)5.95.70.420.39 Gregory (9 May)5.05.40.440.43 Lincoln (19 May)4.85.50.44 P-value0.0090.018 LSD (p=0.05)0.50.01 CV%93 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

19. Frost risk of mid-fast varieties prohibitive All sown at 100 plants/m² Frost sterility Sown into good moisture after small April rain Required irrigation to establish Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

20. Junee 2012 - Experimental design Low plant densities and defoliation (simulated grazing) to increase HI Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Maturity classSowing date 18 April26 April8 May17 May Very slow (Eaglehawk) 50 pl/m² +defoliate 50 pl/m² - defoliate 100 pl/m² + defoliate 100 pl/m² - defoliate Slow (Bolac) 100 pl/m² -defoliate50 pl/m² +defoliate 50 pl/m² - defoliate 100 pl/m² + defoliate 100 pl/m² - defoliate Mid (Gregory) 100 pl/m² -defoliate 50 pl/m² +defoliate 50 pl/m² - defoliate 100 pl/m² + defoliate 100 pl/m² - defoliate Fast (Lincoln) 100 pl/m² -defoliate 50 pl/m² +defoliate 50 pl/m² - defoliate 100 pl/m² + defoliate 100 pl/m² - defoliate

21. Early sown slow maturing wheat managed for HI Junee 2012 (177 mm GSR) Deeper roots, better use of stored soil water and less evaporation $562/ha increase in gross margin (106%)! Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Grain yield (t/ha)50 plants/m²100 plants/m² Variety & sow date Not defoliated Defoliated Not defoliated Defoliated EGA Eaglehawk (18 April) 5.95.66.15.4 Bolac (26 April) 5.85.45.55.3 EGA Gregory (8 May) 5.14.75.24.6 Lincoln (17 May) 4.34.14.04.1 P-value0.034 LSD (p=0.05)0.3

22. There are only two times to sow – on time or early - Peter Ridge Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Junee 2013 5% 6% 28% 45% 5% 3% 14% 12% 5% 4% 11% 7% 3% 8% 4% 7% Frost damage %

23. What about low rainfall? - Condobolin 2011 Stress during late winter and spring reduced grain number Yields comparable Grain yield (t/ha)Harvest index (%) Variety & sow date30 plants/m²90 plants/m²30 plants/m²90 plants/m² Eaglehawk (15 April)3.43.10.370.32 Bolac (27 April)3.32.90.380.35 Gregory (5 May)3.63.20.440.39 Lincoln (16 May) 2.83.00.460.45 Axe (25 May)2.12.60.450.44 P-value0.0290.027 LSD (p=0.05)0.40.02 CV%10.53.4 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

24. What about low rainfall? - Condobolin 2012 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Higher dry matter offset by low HI Yield advantage not as large in low rainfall environments but still worthwhile! 35 plants/m²80 plants/m² Variety & sow dateUn-defoliated Defoliated EGA Eaglehawk (19 April) 3.22.62.7 Bolac (30 April) 3.43.53.2 EGA Gregory (9 May) 3.43.02.8 Lincoln (18 May) 3.02.63.0 P-value<.001 LSD (p=0.05)0.4

25. Bolac – sow early for yield AND quality Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

26. Why do early sown crops yield more? Deeper roots Less evaporation Longer yield formation phase Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

27. Junee 2012 - roots 1.65-1.75 m depth Eaglehawk sown 18 April Lincoln sown 17 May

28. Deeper roots = more water extraction Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

29. Less evaporation = higher WUE Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Variety & sowing date Water- use (mm) Total dry matter (kg/ha) WUE for dry matter (kg/ha.mm) Transpiration (mm) Evaporation (mm) Eaglehawk 18 April3451175634214132 Bolac 26 April3481255636228120 Gregory 8 May344979828178166 17 May321922929168153

30. Less evaporation = higher WUE Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Gregory 100 plants/m² sown 15 AprilGregory 100 plants/m² sown 19 May Both photos taken 29 June 2010

31. Longer yield formation phase Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

32. Yield driven by growth during stem elongation Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Lake Bolac Temora Condobolin

33. Photo of site at anthesis Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Temora 7 October 2011 – Eaglehawk 40 plants/m² sown 15 April 20 spikelets per head

34. Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Temora 7 October 2011 – Lincoln 100 plants/m² sown 19 May 16 spikelets per head

35. Benefits increase at farm level (CSIRO modelling, Julianne Lilley) Strategy 1. Mid-fast varieties only – sowing window opens 5 May 2. Very slow + mid-fast variety – sowing window opens 10 April Location Average farm wheat yield (t/ha) Paddock yields <1.0 t/ha (%) Average farm wheat yield (t/ha) Paddock yields <1.0 t/ha (%) Years in which very slow variety planted (%) Average area of very slow variety planted (%) Condobolin1.548%2.234%71%59% Temora2.922%3.814%78%66% Kerang2.135%3.022%49%37% Lake Bolac4.54%5.05%98%84% Morchard1.644%2.332%29%19% Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

36. Increasing whole-farm wheat yield – 20 day program Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Start Finish Average yield = 4.7 t/ha Start Finish Average yield = 5.5 t/ha Very slow + mid-fast varieties Mid-fast variety only

37. Putting it into practice Sow winter wheats late February – late April (watch WSMV) Revenue tablelands Wedgetail slopes Wylah, Whistler, Rosella western plains Sow slow maturing spring wheats from ~10 April to late April Bolac, Eaglehawk, Forrest Must have stored soil water and be sure crop will emerge!!! Use shovel to check soil is wet to at least 30 cm Pick paddocks that dont need a good knock-down Some diseases are exacerbated by early sowing, consider control options Drop seeding rates on high N paddocks If it doesnt rain, start dry-sowing main-season varieties in late April Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

38. Case study – medium rainfall zone Tony Lehmann, Illabo Bolac sown 15 April 2011 (John Deere disk reduces vigour, increases HI) Yield 5.5 t/ha 13.5% protein Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

39. Wedgetail sown 2 April 2011 80 mm rain April-August 200 sheep for 8 weeks (50 Ha) Yield 2.2 t/ha (CLF_Justica in next paddock with same history yielded 1.7 t/ha) Matt Curtis – 35 km west of Mildura Average annual rain 275 mm Photo and data courtesy Michael Moodie

40. Case study – medium rainfall zone David Kingston, The Rock NSW Bolac sown 20 April 2012 4.0 t/ha, 1% screenings Main season wheat 3.0 t/ha Won district crop competition (Photo taken 6 July 2012 Chris Minehan RMS consulting) Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt

41. What about canola? Dual-purpose canola experiments un-grazed yields (John Kirkegaard, CSIRO & Kalyx) Young 2010 How early is too early? Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Grain yield (t/ha) Crop10 March (S1)22 March (S2)6 April (S3)15 April (S4) Taurus (winter)4.03.43.6 46Y78 (spring)3.73.42.93.6

42. Sustainable Agriculture Flagship James Hunt Research Scientist t+61 2 6246 5066 ejames.hunt@csiro.au wwww.csiro.au SUSTAINABLE AGRICULTURE FLAGSHIP Thank you

43. Protein (%) Very low soil N at sowing (56 kg/ha N to 1.8 m) 370 kg/ha urea (165 kg/ha N) top-dressed 210 kg/ha July 160 kg/ha August Still not enough to make APH in highest yielding treatments! Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Grain yield (t/ha)50 plants/m²100 plants/m² Variety & sow date Not defoliated Defoliated Not defoliated Defoliated EGA Eaglehawk (18 April) 11.011.311.210.0 Bolac (26 April) 12.712.312.813.1 EGA Gregory (8 May) 11.912.112.812.4 Lincoln (17 May) 13.913.314.714.3

44. What about high rainfall? - Lake Bolac 2011 Water limited yield potential - Py = (water-use – 60)*22 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Bolac Lincoln

45. What about high rainfall? - Westmere 2012 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt Establishment poor at first time of sowing - 58, 96, 103 and 122 plants/m² (target 160 plants/m²)

46. What about high rainfall? - Inverleigh 2012 Increasing whole-farm wheat yield and reducing risk through early sowing | James Hunt