Early sowing in Victoria 2014 – how did it go?

GRDC project code: CSP00178

Keywords: stem frost, winter wheat, BYDV, Septoria tritici.

Take home messages

  • Sow spring wheats within 5 to 7 days of their optimum, e.g. if the optimum date for sowing Scout in the southern Mallee is 5 May, don’t sow it earlier than 28 April. Switch cultivars if you want to sow earlier.
  • If sowing before 20 April, winter wheats (Wedgetail, Wylah, Whistler, Revenue, Manning, Adagio, Scenario, Naparoo) have a more flexible sowing window and are at lower risk of stem frost damage than slow maturing spring wheats (e.g. Forrest, Bolac).
  • The last four years of trials have demonstrated that in the majority of Victorian environments, highest yields tend to come from appropriate cultivars established in the last week of April to the first week of May. This may change as better adapted winter wheats become available in the future.

Background

2014 seemed like the ideal year for early sown wheat crops – most districts had an early break and at least some stored soil water. However, a warm May put early sown crops well ahead of average development, and hard frosts in July and August caused severe vegetative damage to many crops. The warm May also extended the presence of aphids, which in southern NSW and north eastern Victoria resulted in severe infestations of barley yellow dwarf virus.

While north eastern Victoria had good finishing rains, late winter and spring were extremely dry in north western Victoria. With drought, heat and frost all playing a role at the end of the season, crops that were sown on-time to slightly early tended to perform best. In south western Victoria, a wet winter carried crops through a very dry spring and crops that were sown on time achieved reasonable yields.

This paper reports on trials conducted across Victoria in 2014 as part of the GRDC early sowing project, as well as trials individually funded by SFS and Baker Seed Co.

Mallee

BCG in conjunction with FAR Australia and CSIRO had an early sowing trial located at Quambatook in the south east Mallee. Treatments included four cultivars (Table 1), two times of sowing (1 April and 6 May), sown at low (50 plants/m2) and standard plant densities (150 plants/m2). Targeted plant densities were not quite attained and actual plant densities were 38 and 88 plants/m². In a ‘weeds’ treatment, tame oat seeds were spread over the plots at a density of 25 seeds/m² prior to sowing to simulate the presence of weeds. There was also a ‘graze’ treatment where grazing was mechanically simulated at Z30 in each cultivar using a line trimmer.

Table 1. Details and disease rating of wheat cultivars used in the experiment at Quambatook.

Variety Maturity Year of release Quality CCN Stem rust Stripe rust YLS

Scout

Mid spring 2010 AH R MR MS S-VS

Lancer

Long spring 2011 APW (APH in NSW) S R MR MS
Rosella Fast winter 1985 ANW/GP S MR-MS MS S

Wedgetail

Mid winter 2002 APW (APH in NSW) S MR-MS MS MS-S

Resistance rating: VS=Very Susceptible, S=Susceptible, MS=Moderately Susceptible, MR=Moderately Resistant, R=Resistant

At the Quambatook site in 2014, 85 days were recorded as having a minimum temperature below 2°C and several events in early August approached -5°C. This severely damaged the spring wheats (Lancer, Scout) sown on 1 April. Lancer at 150 plants/m² suffered 68% mortality on main stems while Scout at the same plant density suffered 94%. At the 1 April sowing, Wedgetail at both plant densities and Rosella at 50 plants/m², were the highest yielding treatments (Table 2).

Wedgetail sown on 1 April out yielded the ‘local best practice’ control (Scout sown 6 May) by 0.3 t/ha (Table 2), and also achieved a higher protein content (13.9% vs 12.1%, Table 3). Although Wedgetail’s screenings and test weight were marginal (Table 4 and 5), when sown at 50 plants/m² it would have achieved a binned grade of APW in Victoria and APH2 in NSW (or if directly marketed in Melbourne etc.). This season APH2 was trading at around a $40/t premium over APW and delivery into NSW, or direct marketing, would have been worthwhile.

Somewhat surprisingly, the slow maturing spring cultivar Lancer was the highest yielding treatment in the trial when sown on 6 May. This was probably because its slower maturity helped it escape a series of frosts in mid-September which would have damaged Scout. The slow maturing winter wheats sown on 6 May were significantly lower yielding than those sown on 1 April.

Table 2. Influence of sowing date, variety and plant density on grain yield at Quambatook.

Yield (t/ha)

Time of Sowing 1 April 6 May
Seeding Rate 50 plants/m²
150 plants/m²
150 plants/m²

Wedgetail

2.0 2.0 1.1
Rosella 1.9 1.7 0.6

Lancer

1.4 1.7 2.3

Scout

1.2 1.1 1.7
Sig. diff. P=<0.001
LSD (P<0.05) 0.2
CV% 10.7

Table 3. Influence of sowing date, variety and plant density on grain protein at Quambatook.

Protein (%)

Time of Sowing 1 April 6 May
Seeding Rate 50 plants/m²
150 plants/m²
150 plants/m²

Wedgetail

13.9 13.5 14.0
Rosella 13.2 14.3 16.3

Lancer

14.6 13.0 12.3

Scout

14.2 14.1 12.1
Sig. diff. P=<0.001
LSD (P<0.05) 1.4
CV% 6.9

Table 4. Influence of sowing date, variety and plant density on screenings at Quambatook.

Screenings (%)

Time of Sowing 1 April 6 May
Seeding Rate 50 plants/m²
150 plants/m²
150 plants/m²

Wedgetail

4.5 6.0 3.2
Rosella 6.4 8.2 2.3

Lancer

5.9 5.3 2.6

Scout

11.7 13.5 3.1
Sig. diff. P=<0.001
LSD (P<0.05) 2.3
CV% 25

Table 5. Influence of sowing date, variety and plant density on test weight at Quambatook.

Test Weight (kg/hL)

Time of Sowing 1 April 6 May
Seeding Rate 50 plants/m²
150 plants/m²
150 plants/m²

Wedgetail

78 77 75
Rosella 82 81 78

Lancer

77 81 80

Scout

74 77 78
Sig. diff. P=<0.001
LSD (P<0.05) 3.1
CV% 3.0

Sowing slow maturing cultivars such as Wedgetail at low plant density (50 plants/m²) did not decrease their competitive capacity. Winter wheats (Wedgetail and Rosella) were much more competitive than Scout, but some of this effect was probably due to the stem frost damage sustained by Scout at the early time of sowing (Table 6).

Table 6. Influence of simulated weed population (tame oats) on grain yield of wheat sown 1 April at different plant densities.

Seeding Rate 50 plants/m²
150 plants/m²
 Cultivar  No weeds Weeds % yield loss No weeds Weeds % yield loss

Wedgetail

2.0 1.8 10 1.9 1.6 16
Rosella 1.9 1.5 21 1.8 1.5 17

Lancer

1.3 1.1 15 1.6 0.8 50

Scout

1.3 0.7 46 1.1 0.7 36
Sig. diff. P=<0.034
LSD (P<0.05) 0.3
CV% 15.4

Slow maturing varieties sown early provided more dry matter for grazing than faster varieties sown later (Table 7). Defoliation of the first time of sowing did not significantly affect yield in Wedgetail but increased yield in Rosella. Defoliating Scout sown early increased yield. This was probably due to reduced stem frost damage. Defoliating Scout sown 6 May did not reduce yield. There was no effect (main or interaction) of grazing on protein, screenings or test weight.

Table 7. Grain yield for different cultivars at different times of sowing.

 

Grain yield (t/ha)

Dry matter at grazing (t/ha)

Time of sowing

Cultivar

Ungrazed

Grazed

1 April

Wedgetail

2.0

1.8

1.6

 

Rosella

1.7

1.9

1.8

 

Lancer

1.7

1.7

1.1

 

Scout

1.1

1.5

1.1

6 May

Wedgetail

1.1

1.2

1.2

 

Rosella

0.6

0.9

1.1

 

Lancer

2.3

1.9

1.1

 

Scout

1.6

1.6

1.3

Sig. diff.

 

P<0.001

P<0.001

LSD (P<0.05)

 

0.2

0.2

CV%

 

8.3

13.1

The results of the Quambatook trial clearly show how sowing a proportion of wheat area early with slow maturing cultivars when the opportunity arises increases whole farm wheat yield and profitability. At present, the most reliable options for sowing before 20 April in the Mallee are winter wheats, particularly Wedgetail. Grazing winter wheats provides excellent feed during the winter feed gap and eases pressure on pastures for greater production in spring. This in turn increases potential stocking rates and hence the profitability of livestock enterprises.

SW Victoria

Westmere, Inverleigh and Hamilton - ToS v cultivar

These trials were classic time of sowing (ToS) x cultivar trials with three to four sowing dates and six to eight cultivars at each time of sowing depending on the site. At all sites, highest yields in the majority of cultivars came from either the late April or mid-May sowing dates, and this period spans the optimal sowing dates for most cultivars adapted to SW Victoria (Tables 8, 9 and 10).

Beaufort was the stand-out performer in the feed wheats, particularly at Westmere and Hamilton. Trojan and Derrimut were the highest yielding milling wheats. Both these varieties have an optimal sowing date in SW Victoria of ~15 May, but in the very dry and relatively frost free (in south west Victoria!) spring of 2014, they also performed well when sown ‘too early’ in late April-early May particularly, at Westmere. However, when sown on 10 April at Inverleigh both cultivars were heavily damaged by frost.

Table 8. Grain yield for different sowing times and cultivars at Inverleigh in 2014.

Grain yield (t/ha)

 

Time of sowing

Cultivar

Maturity

10-Apr

28-Apr

12-May

26-May

Feed

 Beaufort

Slow spring

4.3

5.0

3.6

3.6

 Revenue

Slow winter

3.7

3.5

4.9

4.3

Milling

 Forrest

Very slow spring

3.5

3.8

3.1

3.4

 Bolac

Slow spring

4.3

4.0

3.3

3.2

 Kiora

Mid-slow spring

3.0

3.7

3.2

3.1

 Derrimut

Mid spring

2.2

4.3

4.8

4.7

 Trojan

Mid spring

2.0

4.4

4.7

3.7

P-value

 

<0.001

LSD (P=0.005)

 

0.6

Table 9. Grain yield for different sowing times and cultivars at Westmere in 2014.

Grain yield (t/ha)

Time of sowing

Cultivar

Maturity

8-May

21-May

4-Jun

Feed

Revenue

Slow winter

5.6

5.1

4.6

Beaufort

Slow spring

6.3

6.1

5.0

Preston

Mixed spring

5.6

5.4

4.4

Milling

Forrest

Very slow spring

5.0

4.8

4.8

Bolac

Slow spring

5.3

4.5

4.6

Kiora

Mid-slow spring

5.5

5.3

4.9

Trojan

Mid spring

5.7

5.7

5.3

Derrimut

Mid spring

5.8

5.5

5.0

 

P-value

0.005

 

LSD (p=0.05)

0.4

Table 10. Grain yield for different sowing times and cultivars at Hamilton in 2014.

Grain yield (t/ha)

 

Time of sowing

Cultivar

Maturity

1-May

16-May

5-Jun

Feed

Beaufort

Slow spring

6.1

6.3

4.7

Revenue

Slow winter

5.4

6.0

4.6

Milling

Forrest

Very slow spring

5.3

5.3

4.5

Bolac

Slow spring

4.7

5.3

4.7

Derrimut

Mid spring

5.7

6.4

4.9

Trojan

Mid spring

5.5

6.5

5.1

P-value

 

<0.001

LSD (P=0.05)

 

0.5

Inverleigh – winter wheat agronomy

This trial aimed to compare winter wheat cultivars all sown early (10 April 2014), and different management treatments applied to Revenue, currently the most widely grown winter wheat in south western Victoria. Revenue and Scenario were the highest yielding cultivars (Table 11). While light grazing at Z16 and Z30 significantly increased yield of Revenue relative to the ungrazed control, heavier grazing at Z30 reduced yields relative to light grazing though these treatments were not significantly different to the control. Seeding density or N timing did not affect grain yield of Revenue. N strategy had no significant affect on Z16 or Z30 dry matter available for grazing, with both having a mean of 2568 kg/ha removed in total, representing 1712 DSE/ha.days.

Table 11. Grain yield for different winter wheat cultivars and different management treatments applied to Revenue sown 10 April at Inverleigh.

Cultivar Seeding density (seeds/m²)  Defoliation  N strategy  Grain yield (t/ha)

Manning

250 nil grain 3.2
Scenario 250 nil grain 4.3
Wylah 250 nil grain 2.8

Revenue

150 nil grain 4.0

Revenue

250 nil grain 3.9

Revenue

250 nil grain 3.9

Revenue

250 Z16 (uniform light) + Z30 (level 1) forage 4.5

Revenue

250 Z16 (uniform light) + Z30 (level 2) forage 3.8

Revenue

250 Z16 (uniform light) + Z30 (level 3) forage 3.7

Revenue

250 Z16 (uniform light) + Z30 (level 3) grain 3.6
P-value <0.001
LSD (p=0.05) 0.3

Defoliation N Strategy

Grazing – All plots mechanically defoliated uniformly during tillering (GS16) then differentially at GS30 as follows:

  • Level 1 (cut high GS30), level 2 (intermediate GS30) and level 3 (cut low GS30)
  • Forage N – 75N at sowing / 125N post defoliation GS30-31 / 100N GS32-33
  • Grain N – 50N at tillering / 125N GS30-31 / 125 N GS32-33


Inverleigh - early season disease control

In south western Victoria one of the biggest barriers to early sowing is disease pressure from Zymoseptoria tritici (formerly known as Septoria tritici or Septoria tritici blotch - STB). Work on early sown Revenue feed wheat (rated MR-MS for STB) in 2014 illustrated that in furrow applications of flutriafol (at the higher rate loadings - 200g ai/ha) gave good early control of the disease which was equal in effect to an application of a foliar fungicide at Z31. The seed treatment Jockey® (containing fluquinconazole) gave suppression of STB but was significantly inferior to flutriafol (Figure 1). It is also worth noting the effectiveness of grazing prior to pseudo stem erect (Z30) which had the same effect as the different fungicide options and was superior to Jockey® seed treatment. 

Figure 1. Influence of early applications of seed treatment, in-furrow flutriafol, grazing and GS31 fungicide on Zymoseptoria tritici (STB) control in early sown wheat (April 11) – cv Revenue, Inverleigh, Victoria 2014.

Figure 1. Influence of early applications of seed treatment, in-furrow flutriafol, grazing and GS31 fungicide on Zymoseptoria tritici (STB) control in early sown wheat (April 11) – cv Revenue, Inverleigh, Victoria 2014. 

Note. Flutriafol in furrow applied at high rate (200 g/ha ai); Foliar Fungicide applied at GS31 & GS39 was Prosaro® 300ml/ha (NB this product whilst approved for use in wheat does not have a registration for control of STB); Jockey® Stayer® applied at 450ml/100kg seed

NW Victoria

Baker Seed Co established individual cultivar experiments at three times of sowing at Rutherglen (Table 12). While the three different trials cannot be statistically compared, the highest yields in the 29 April sowing date came from slow to mid-fast maturing cultivars. Yields at the first time of sowing were reduced by severe BYDV infection due to late persistence of aphids in the warm May conditions. This serves as a good reminder that seed of early sown wheat crops needs to be treated with an appropriate insecticide (e.g. imidacloprid) which needs to be backed up with a foliar insecticide (e.g. Karate®, Transform® etc) if aphids are present past the start of tillering.

Table 12. Grain yield for different sowing times and cultivars in Baker Seed Co trials Rutherglen in 2014. Not all cultivars were planted at each time of sowing, and only means within each time of sowing can be statistically compared using LSDs. Treatments highlighted in grey would have flowered very early and either been damaged by frost or incurred excessive frost risk.

Grain yield (t/ha)

Cultivar Maturity Time of sowing
16-Apr* 29-Apr 30-May
Adagio Slow winter 5.4 - -

Revenue

Slow winter 4.4 - -

Naparoo

Mid winter 5.5 - -

Wedgetail

Mid winter 5.0 6.4 -

Forrest

Very slow spring 6.0 - -

Bolac

Slow spring 4.9 - -

Lancer

Slow spring 4.5 6.4 -

Kiora

Mid-slow spring 5.0 6.6 -

Mitch

Mid spring 3.3 6.3 -

Trojan

Mid spring 3.3 6.9 5.3

Viking

Mid spring - 5.6 5.1

Elmore CL Plus

Mid-fast spring - 5.5 5.1

Gauntlet

Mid-fast spring - 6.2 -

Suntop

Mid-fast spring - 6.1 5.0

Cobra

Fast spring - 6.7 5.3

Condo

Fast spring - - 5.0

Corack

Fast spring - - 4.8

Emu Rock

Fast spring - - 4.8

Wallup

Fast spring - - 4.9
P-value <0.001 0.003 0.001<
LSD (P=0.05) 0.6 0.8 0.4

*All treatments at this ToS severely infected with BYDV

Conclusions

Mallee

Based on four years of trials and farmer experience in 2014, there is the potential for winter wheats (e.g. Wedgetail) to allow growers to take advantage of early planting opportunities (from March to late April) in the Mallee. However, given the poor adaptation of Wedgetail to alkaline soils, yields are unlikely to be higher than faster spring varieties sown in their optimal usual window, but the grazing potential of early sown winter wheats could be attractive to farmers with livestock.

In the Mallee the sowing window for adapted spring wheats opens in late April with mid maturing cultivars Trojan, Phantom, Yitpi, Magenta and Estoc having an optimum sowing date between 25 April and 1 May depending on location. Mid-fast springs such as Scout, Correll, Kord and Grenade have an optimum around 1-5 May, and fast maturing cultivars such as Mace, Corack and Emu Rock around 5-10 May.

SW Victoria

Four years of trials have demonstrated that in south western Victoria, highest yields come from sowing dates between ANZAC day and mid-May. Bolac, Beaufort and Kiora have optimal sow dates around 25 April - 1 May. Winter wheats such as Revenue, Manning, Scenario and Adagio can be sown much earlier than this, but are unlikely to yield more than if they were sown in late April-early May, in part due to STB pressure in the south western Victorian environment. However, there is an advantage in sowing winter wheats early for grazing (as early as November the year before harvest!), and defoliation by grazing has been shown to be an effective means of controlling STB. Forrest has an optimum sowing date ~15 April which is problematic given the STB pressure that can be encountered planting at this time. Mid-maturing cultivars DerrimutA and TrojanA have an optimum sow date around 15 May.

NW Victoria

Winter wheats bred in southern NSW (Wedgetail, Whistler) perform better in this environment than the rest of Victoria and have historically been the best options for early sowing and dual purpose use. More recently released slow maturing spring cultivars (Bolac, Lancer, Kiora) suited to late April sowing also perform well in north western Victoria. As with other environments, in 2014 highest yields of spring wheats came from crops sown in the last week of April to the first week of May. All early sown wheat seed should be treated with imidacloprid (Gaucho, Emerge etc.) which needs to be backed up with a foliar insecticide (e.g. Karate®, Transform®) if aphids are present past the start of tillering.

Contact details

James Hunt
GPO Box 1600, Canberra ACT 2601
0428 636 391
james.hunt@csiro.au
@agronomeiste

GRDC Project Code: CSP00178,