GRDC Grains Research update for advisers 2008
| Date: 20 Jun 2008
Where will the canola industry be in five year’s time?
Felicity Pritchard, Trent Potter, Wayne Burton, Steve Marcroft, Don McCaffery, Kate McCormick.
TAKE HOME MESSAGE
Canola has the potential to increase cropping returns as a rotational crop and also in its own right.
SETTING THE SCENE
Over the past few years, with a series of late breaks or droughts, canola has fallen out of favour in some areas. However, canola has proved to be a crop that fits well into rotations.
IMPACT OF NEW HYBRIDS
Hybrid canola varieties have been in Australia since the early 1990s but it is only in the past few years that hybrids have shown their potential. Whether this has been due to hybrid vigour and therefore high yield potential or due to very high blackleg resistance is a moot point. One reason why we have not seen the impact of hybrids in Australia is due to blackleg and the need to have resistance in both parents. Quite often by the time the inbreds are converted into hybrid parents the resistance has already broken down. Beginning with the sylvestris based hybrid Hyola 60 we have seen high yields achieved in Australia, while in Canada, hybrids now produce significantly higher grain yields than open-pollinated varieties.
In future, with new varieties coming from private companies, we will see more hybrids on the market. Currently several of the highest yielding conventional and Clearfield varieties are hybrids.
While some farmers retain sowing seed of open-pollinated varieties it has been demonstrated in Canada that F2 seed harvested from hybrids can be up to 13% lower yielding than the hybrid it was derived from. Therefore retaining seed from a hybrid for the next crop is a big penalty.
Hybrids have generally been sown at lower sowing rates than open-pollinated varieties due to greater seed size and hybrid vigour. Trials conducted at Cummins and Struan in SA as part of the Better Canola project showed that sowing rates as low as 2 kg/ha were adequate for high grain yields from hybrids, provided pests and diseases were controlled.
SPECIALTY VARIETIES
New specialty canola varieties which produce oils that are more stable at higher cooking temperatures, while maintaining very low levels of saturated fats and no trans fats, are now available to growers.
The development of the specialty canola is the Australian Oilseeds Federation’s top priority, as demand continues to grow. In Canada, 200,000 hectares of specialty canola varieties were sown in 2005 and over 400,000 hectares in 2007. Cargill Australia is anticipating the opening of a major new global market for specialty canola varieties, to meet the expected demand for the healthier oils. Locally there is a market to replace currently imported Palm oil, with over 10,000 tonnes being used currently, with a potential for 5-10 fold increase.
Specialty varieties traditionally have a yield penalty associated with them, but some newer Australian-developed varieties have yielded comparably to some of the leading non-specialty conventional or Clearfield varieties.
This year there will be four new varieties available through Cargill and the Nuseed Crop Network: one conventional, two triazine tolerant varieties, and for the first time in Australia, a conventional specialty hybrid.
Specialty varieties have been developed by Nuseed and the Victorian Department of Primary Industries/Cargill, with the aim of producing higher yielding specialty varieties suited to local conditions. Priorities for both programs include the development of herbicide tolerant cultivars, with high blackleg resistance, consistent quality performance together with high yield potential.
JUNCEA CANOLA FOR LOW RAINFALL ENVIRONMENTS OR SPRING SOWING
This year two juncea canola varieties will be available, the conventional variety Dune (released on a small scale in 2007) and a new Clearfield variety called Oasis CL, (both cultivars are being marketed by Pacific Seeds under an End Point Royalty system).
These are Australia’s first canola quality Brassica juncea varieties, with major changes to both the oil and meal quality from traditional table mustard. The varieties were bred by Victorian DPI and Viterra, in Canada, and partly funded by the GRDC.
Juncea canola has a number of advantages over traditional canola in low rainfall areas, including faster ground covering ability, better heat and drought tolerance and shatter tolerance - thus it does not need windrowing (saving around $26/ha). It is also a spring sowing option in high rainfall areas of SE SA and the Victorian Western District.
The new Clearfield variety OasisCL line has performed well in multi-location breeding trials and will be re-tested and entered into NVT trials in 2008. As in other years in multi-location breeding trials, Dune (tested for the first time in NVT trials in 2007) has performed similar to the conventional early season variety AG-Outback. New conventional earlier maturing canola quality B. juncea lines (Dune replacements) will also be further evaluated in 2008.
Future breeding priorities include further development of herbicide tolerant varieties with high yield, improved quality, good blackleg resistance and good adaptation. The first triazine tolerant advanced breeding lines will be in multi-locations trials in 2008, with first cultivars hopefully available in 2011. Hybrids and other herbicide tolerances are also currently being developed.
Juncea canola lines tend to yield the same or more than traditional canola in situations where canola yields are equal or less than 1.5 t/ha. The first breeding lines to meet all the quality criteria were in multi-site trials in 2004 (Table 1).
Table 1: Average yield and quality data of juncea canola advanced breeding lines from multi-location trials in SA and Vic 2004 and 2005*, compared with AG-Outback , a traditional canola variety for low rainfall areas
|
Line
|
Yield (t/ha), (% of AG-Outback)
|
Oil content (%)
|
Meal protein content (%)
|
|
|
Year
|
2004
|
2005
|
2004
|
2004
|
|
Dune (JR055)
|
1.33 (100%)
|
0.95 (100%)
|
37.5
|
40.5
|
|
JT004
|
1.37 (103%)
|
1.02 (108%)
|
36.0
|
40.9
|
|
AG-Outback (control)
|
1.33
|
0.95
|
36.1
|
39.1
|
|
Sites
|
|
|
|
|
STRATEGIES FOR REDUCING THE RISK
Until recently, canola gained a reputation of being a more risky crop than cereals since the late 1990s, with a run of seasons with late breaks, little or no subsoil moisture and in some years poor prices. However, these break crops are critical to successful cereal cropping for disease and weed management. Variable costs to grow canola are around $290/ha in the Wimmera which will increase further in 2008 due to price increases of inputs. Some of the cost increase will be offset by high grain prices currently on offer. Strategies to reduce some of the up-front costs include strategic use of nitrogen fertiliser and deferring herbicide applications to post emergent where possible to see if they are really needed. Choosing paddocks with stored nitrogen and water will also reduce risk associated with growing canola. Timely sowing maximises yield potential and by default reduces risk. Having alternative end uses for canola also reduces risk by creating another source of income. Strong price signals for canola in the medium term also take much of the risk out of growing the crop. These strategies are discussed in more detail below.
Grazing canola
Research suggests if canola is sown early (by mid-late April), it can be grazed in winter.
The feed is excellent quality. In preliminary trials in high rainfall areas, the combined value of stock feed and grain can be more profitable than grain alone.
Canola hay and silage
In recent years with below average rainfall and variable canola performance, cutting canola for hay has provided an alternative income source for some growers.
Demand
The prolonged dry period and subsequent water and fodder shortage has created a new opportunity for canola growers to market their failed crops as hay or silage with canola hay becoming more accepted by the dairy industry. The dairy industry has indicated that lucerne or cereal hay are still preferred due to their familiarity with these products but canola hay could still have a place if priced low enough in comparison and is becoming more accepted as the dairy industry is exposed to it. Canola hay and silage are safe to use as long as feeding guidelines are followed.
Quality
Good quality Canola hay is an excellent source of energy and protein and is highly palatable. Last year, the quality of canola hay submitted to FeedTest was similar to 2006 and with a similar wide range of quality. The mean values were higher in protein than typical cereal hay but similar in energy and digestibility.
Table 2: Canola hay quality for 2006 and 2007 (source: Feedtest)
|
Baled canola hay
|
|
Crude protein (%)
|
Dry matter digestibility (%)
|
Metabolisable energy (MJ per kg dry matter)
|
|
2007
|
Average
|
15.0
|
65
|
9.6
|
|
|
Range
|
8.7-27.7
|
35-83
|
4.4-13.1
|
|
2006
|
Average
|
15.9
|
66.4
|
9.8
|
|
|
Range
|
4-27
|
33-85
|
4-13
|
Better Canola hay trials
Two trials were conducted as part of the Better Canola demonstration program at Longerenong College in 2007. The trials were conducted by BCG for the Better Canola project, managed by a Victorian steering committee for a national project coordinated by Steve Marcroft, funded by the GRDC and AOF.
Time of cutting
The first trial was a time of cutting trial in a commercial crop of Tornado TT. This trial also compared harvesting for grain against hay production.
Cutting at mid flowering produced significant higher quality (higher protein, digestibility and energy and lower fibre) than cutting at late flowering but the earlier cutting time produced significant less hay yield. The hay cut at late flowering produced higher yields and good quality feed, with high energy and protein levels (Table 3). Cutting at mid pod-fill, produced similar dry matter to the late flowering timing but quality had deteriorated significantly. This detected change in quality is consistent with previous results (Phillips 2007).
Table 3: Dry matter and Quality of canola hay cut at early (HC1) and late (HC2) flowering in the 2007 Better Canola trial.
|
Time of Cutting
|
Date
|
Hay Yield t/ha
|
Residual dry matter %
|
Crude protein % (dry matter basis, DMB)
|
Neutral detergent fibre % (DMB)
|
Dry matter digestibility %
|
Metabolisable energy (MJ/kg dry matter)
|
|
Mid flowering
|
6 Sep 2007
|
3.1
|
87
|
28
|
24
|
86
|
13
|
|
Late flowering
|
27 Sep 2007
|
3.9
|
91
|
18
|
33
|
74
|
11
|
|
Mid pod fill
|
17 Oct 2007
|
4.0
|
91
|
15
|
38
|
68
|
10
|
|
Lsd (P<0.05)
|
|
0.62
|
|
2.7
|
3.43
|
4.4
|
0.73
|
Economic analysis
Table 4: Gross margin for canola hay cut at late flowering, or early flowering or grain at two hay prices, based on results from 2007 Better Canola hay trial at Longerenong.
|
End Product
|
Yield (t/ha)
|
Oil (%)
|
Commodity Price ($/t)
|
Gross Income ($/ha)
|
Total Costs ($/ha)
|
Gross Margin ($/ha)
|
|
Grain
|
0.4
|
35.3
|
535
|
214
|
240
|
-26
|
|
Early Flowering
Hay
|
3.1
|
*
|
270
|
837
|
362
|
476
|
|
“
|
“
|
*
|
200
|
620
|
360
|
260
|
|
Late Flowering
Hay
|
3.9
|
*
|
270
|
1053
|
392
|
661
|
|
“
|
“
|
*
|
200
|
780
|
390
|
390
|
Hay production regardless of the time of cutting was more profitable than harvesting the crop for grain. A frost event in mid October caused significant damage and reduced grain yield potential. Cutting at late flowering produced a more profitable result than early flowering at a given hay price. Canola cut at early flowering was better quality, but produced lower hay yields, requiring a $60/t premium to compensate for this. Although not presented in Table 4, the gross margin for the mid pod-fill cut was similar to the late flowering cut (as dry matter production was similar) assuming the same price could be achieved for the hay despite the drop in quality.
Hay production is not without risk (weather damage, volatile markets) but does provide an option in some seasons.
Varieties
The second trial compared two Clearfield canola varieties and two TT canola varieties cutting for hay at late flowering and mid pod-fill with grain production
The hybrid Clearfield varieties 45Y77 and 46Y78 produced more hay at both timings and more grain than the TT varieties Tornado TT and ATR-Barra. There were no significant differences in oil content (Table 5). Hay quality was affected by time of cutting but not by variety. Table 6 illustrates the drop in quality resulting from the later time of cutting.
Table 5: Hay and grain yield for four canola varieties at Longerenong 2007
|
Parameter
|
Harvest Date
|
Clearfield Hybrid
|
TT
|
LSD
(P<0.05)
|
||
|
|
|
45Y77
|
46Y78
|
ATR-Barra
|
Tornado TT
|
|
|
Late flowering Hay (t/ha)
|
17 Oct 2007
|
4.4
|
3.9
|
3.2
|
2.9
|
0.59
|
|
Mid pod fill Hay (t/ha)
|
1 Nov 2007
|
3.8
|
3.7
|
3.1
|
2.8
|
0.71
|
|
Seed Yield (t/ha)
|
20 Nov 2007
|
1.10
|
1.07
|
0.66
|
0.66
|
0.16
|
|
Seed Oil (%)
|
|
35.5
|
36.5
|
37.1
|
36.1
|
NS
|
Table 6: Effect of timing of hay cutting on quality (mean of four canola varieties) at Longerenong 2007
|
Timing
|
Harvest Date
|
t/ha
|
Residual dry matter %
|
Crude protein % (dry matter basis, DMB)
|
Neutral detergent fibre % (DMB)
|
Dry matter digestibility %
|
Metabolisable energy (MJ/kg dry matter)
|
|
Late flowering Hay
|
17 Oct 2007
|
3.6
|
91.4
|
17.1
|
35.8
|
71.6
|
10.7
|
|
Mid pod fill Hay
|
1 Nov 2007
|
3.4
|
94.6
|
15.8
|
48.5
|
60.10
|
8.7
|
|
|
LSD (P<0.05)
|
NS
|
0.54
|
1.6
|
3.0
|
3.8
|
0.64
|
However, growers are reminded that nutrient export from hay crops can be very high and this needs to be considered when planning for 2008 (Table 7). A soil test in autumn is a must for paddocks that were cut for hay last season.
Table 7: Approximate macronutrients present in canola grain, straw or hay when cut at early flowering.
|
Product
|
N
|
P
|
S
|
K
|
|
Grain
|
30
|
5
|
5
|
10
|
|
Straw
|
4
|
3
|
1
|
3
|
|
Hay
|
30
|
3 **
|
8 **
|
25
|
Time of sowing, sowing rates and subsoil moisture
The ideal sowing time for canola is late April to mid-May for low to medium rainfall areas such as the southern Mallee, Wimmera, northern Victoria and the northeast, but this can be extended until mid-June. In the Mallee and on the upper Eyre Peninsula, canola is an opportunity crop and should only be sown before the end of May to take advantage of a good early break and a favourable seasonal forecast. In the high rainfall districts such as the Western District and lower South East, canola is best sown on well-drained soils anytime from the beginning of May onwards. Later sowings are possible because of the better chance of cool and moist conditions in spring.
If early sowing is not possible this year, choose an earlier maturing variety if in a high rainfall zone and start to weigh up your options if in medium rainfall zone.
Delayed sowing usually reduces oil content and yields due to hotter drier conditions during pod filling. Canola and Brassica juncea yields drop by an average 5% per week delay in sowing, but can be much more in years with a dry spring, and less in years with a gentle finish. Cereal yields are generally less affected by late sowing than canola. Oil content in canola also drops by about 0.5% per week as sowing is delayed beyond the optimum.
Very early sown crops can produce excessive growth and potentially hay off and sometimes lodge. New research suggests that in high rainfall regions crops can be grazed to reduce the extra biomass and still produce grain.
Sowing rate is also an area that can be re-assessed. As a general rule 1 kg seed per hectare equates to 25 plant/m2. The adoption of press wheels has improved germination of canola. Plant densities of 30-50 plants/m2 are ideal for the medium rainfall areas, while 50-75 is ideal in southern Victoria, and many growers are achieving much higher plant densities than this. Resowing is not necessary unless plant populations are very low, at or below 10-20 plants/m2.
Nitrogen management
Rates
Nitrogen rates need to be matched to target yields, and a new potential yield calculation has been developed by CSIRO for southern NSW, which is simple but 20% more accurate than the French-Schultz model, which is still used by most agronomists. With the new calculation, target yields are 85% of potential yields. Refer to “Maximising Canola Performance” under: http://www.grdc.com.au/director/events/researchupdates?pageNumber=95 for further details.
The published amount of N removed in one tonne of canola grain ranges from 30 to 40 kg/ha. The rule of thumb is that canola requires 80 kg/ha N to produce one tonne of grain – however, this is open to debate. The 2001 Topcrop State Focus measured N use efficiency, taking into account deep soil nitrate level (0-60 cm), estimated in-crop mineralisation and applied fertiliser nitrogen. Using this calculation, one tonne of canola grain required as little as 30 kg/ha total N in the Wimmera up to 120 kg/ha N in the Western District, where waterlogging limited yields. As N rates increased the N use efficiency tended to decrease. Oil content may be affected by N and high N rates up-front may lead to lodging in high rainfall and irrigation areas.
Timing
Fertiliser, particularly nitrogen, is the biggest single variable cost for canola and carries with it financial risk if the season shapes up poorly. Trials at Wagga Wagga, Forbes, Bendigo and Condobolin have shown that delaying or splitting N fertiliser applications usually has no yield penalty associated with it when there is at least 40 kg/ha N in the top 50 cm at sowing time (Norton R., pers. comm.).
Fungicides
Fungicide seed treatments have their place, but responses are much less likely with blackleg resistant varieties – and in Victoria, there’s usually no advantage in using a fungicide when the blackleg rating is over 7. In Southern NSW, responses to fungicides are more common, but are far less marked in resistant varieties (Kirkegaard et al., 2006). Different products vary in their efficacy: Jockey worked in 30% of cases, Impact in 50% and Maxim had little effect in southern NSW trials in 2005. Despite this, Jockey was more cost-effective in the trials, on average.
Retained seed
This is becoming common practice in some regions. Sowing retained seed may be false economy and is not recommended, as trials have shown an average 12% yield decline with poor-quality retained seed (and in one case, complete crop failure) when the crop suffered from a dry finish (Marcroft. et al., 1999). Yields ranged from 0.1 up to 1.2 t/ha for farmer-retained seed, compared with a more consistent 1.0 to 1.2 t/ha for certified seed.
If considering retaining seed, growers should be aware of the costs associated with germination testing, grading, storage, and potential weed problems. Growers should never retain seed from a crop which was planted from retained seed due to potential changes in the variety’s characteristics due to genetic drift as a result of outcrossing (Marcroft. et al., 1999)
Contact: Trent Potter
Ph: 08 87629132
Email: Potter.Trent@saugov.sa.gov.au
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