Pulse check 2015 - agronomy and variety update

GRDC project codes: DAV00113, UA00127, DAV00072, DAV00071, DAN00151, DAS00131, DAS00112, S0213

Keywords: pulse varieties, herbicide tolerance, green lentils, kabuli chickpea, faba bean.

Take home messages

• Four new pulse varieties were released for southern Australia in 2014. The faba bean (PBA Samira) and large red lentil (PBA Jumbo2) still performed well in target production regions despite extremely dry finishing conditions in 2014 and offer very high yields, improved disease and other agronomic advantages over older varieties.
• The two new green lentil varieties PBA Greenfield and PBA Giant will offer growers a new alternative to manage production and marketing risks, but are generally a higher input lentil and require careful consideration.
• XT lentil varieties have improved tolerance to residues of Group B herbicides compared with conventional lentils, but still can incur yield loss in some situations. Where Group B residues are not an issue, or requirements for in crop application of imazethapyr are not required, careful consideration should be made to the yield and other trait benefits of several other conventional lentils which may prove more profitable.
• The net income of from PBA Monarch over 2012-14, a new medium sized kabuli chickpea, was about $70/ha/annum and $200/ha/annum greater than Genesis 090A and more than double the desi, PBA Striker in the Wimmera and southern Mallee, respectively, even though grain yields were similar.
• Recent trial results indicate faba beans may have a fit in the lower rainfall zones, particularly with ongoing improvements in varieties and management.
  • Following an excellent early break with above average rainfall recorded in April, most growers were able to sow and establish pulse crops in a timely manner. Unfortunately rainfall was well below average for the rest of the season. Both annual and growing season rainfall was approximately 40 per cent less than long term averages at both Southern Pulse Agronomy (SPA) research sites. In the critical reproductive period for pulse of August to October rainfall was about 75 per cent less than long term average.

2014 seasonal snapshot

• Pulse grain yields were highly variable in 2014, ranging from failed crops on the heavier soils of the southern Mallee, through to average to above average in the central and northern Mallee on some of the sandier loam soils and regions that experienced extensive summer rainfall. Yields were significantly impacted by the extremely dry spring conditions, combined with frost in many regions. Grain quality was surprisingly good given the extensive frosts experienced.
• Autumn and early winter temperatures were generally warmer than average, however late winter and spring produced some extreme cold events. At the Wimmera pulse agronomy site, 40 days between Aug 1 and Oct 17 experienced overnight frost conditions, severely impacting yields.
• Given the excellent early start to the season there were early signs that disease may become a significant issue in pulses throughout spring. However, given the extremely dry weather epidemics never eventuated and any disease was generally well managed.

New lentil varieties and management

PBA Jumbo2 is the highest yielding large seeded red lentil, approximately 10% higher than PBA Jumbo. In Victorian conditions, PBA Jumbo2 has long term yields equivalent to PBA Ace and slightly above PBA Bolt. Performance in the difficult conditions of 2014 replicated these previous results, confirming yield stability across a range of regions and environments. PBA Jumbo2 is a direct replacement for PBA Jumbo and Aldinga having a similar seed size with grey seed coat. It is resistant to foliar and seed ascochyta blight (AB) and resistant to botrytis grey mould (BGM) with mid flowering and maturity similar to PBA Jumbo. Tolerance to soil boron is similar to PBA Flash. PBA Jumbo2 has a large and vigorous plant type (greater than PBA Ace in the more mild winter conditions experienced in South Australia) that aids in weed competition and sets up high yield potential.  Agronomic work is currently ongoing to investigate if seeding rate and sowing date manipulation are required to optimise its performance across a range of seasons and environments. As with other large seeded varieties, PBA Jumbo2 is well suited to the post-harvest removal of small broadleaf weeds seeds, however it does not have the XT herbicide technology.

A 'green' future for lentils

In Australia we have yet to develop a substantial green (yellow cotyledon) lentil industry, despite significant opportunities on the world markets (Canada produce and export in excess of 0.5M tonnes annually) and a small domestic market. Traditionally, Canada produced more green lentils than red, but recently trends have changed with an estimated 1.1MT of reds produced in 2014 compared with 0.59MT of greens. Similar trends are expected in 2015 and Canadian lentil area estimates are currently at record levels of 3.8 to 4.0 M acres, as growers respond to high prices. Expansion of the Australian green lentil industry may allow some growers to spread their production, management and marketing risks, particularly if production trends and seasonal forces combine in Canada to help produce large worldwide red lentil stocks.

In the 2014, PBA released the first broadly adapted high yielding, reliable and marketable varieties, PBA Giant and PBA Greenfield to Australian growers. These varieties replace the initial green varieties, Matilda, which was medium in size and susceptible to disease and Boomer, released in 2005 with a larger seed size and improved disease resistance enabled successful production in some areas, however it was prone to shatter and acceptable seed colour often difficult to achieve.

Green lentils are generally sold and consumed whole with the seed coat intact and the markets prefer large uniform seed size with good green colour retention (lack of bleaching) and an absence of seed blemishes such as disease and wrinkled seed coat. Smaller markets exist for medium and small sized green lentils.

PBA Giant is the largest seeded Australian green lentil, broadly adapted with similar yield and improved shattering resistance compared to Boomer. It produces a slightly larger and more consistent seed size (average diameter 5.8mm). It has moderate resistance to AB but is rated moderately susceptible to BGM and monitoring and timely application of fungicides will be important to ensure the control of disease, including strategic fungicide applications at podding to minimise seed staining from AB. Although improved over Boomer, PBA Giant has a shattering rating of MR/MS and therefore timely harvest is still vital to prevent seed loss and bleaching of coat colour.

PBA Greenfield is the highest yielding Australian green lentil available, broadly adapted with good early vigour and moderate resistance to AB and BGM. PBA Greenfield is mid flowering and like other green lentils is mid to late in maturity. In long term trials it has produced grain yields averaging 11 to 14% higher than the red lentil variety Nugget and averages 11% higher grain yields than Boomer. PBA Greenfield has improved shattering resistance over both Boomer and PBA Giant with an MR rating, however timely harvest is still important to produce good coloured seed. This may also be aided by strategic fungicide applications during podding to minimise seed staining from AB.

In 2013 and 2014, agronomic trial work conducted by SPA assessed the impact of sowing time, disease management, desiccation/crop topping and harvest timing on the yield and quality of the new varieties.

Some key findings include:

• early sowing is essential to maximise yield potential in dryer (Mallee) environments;
• monitoring for disease and timely application of fungicides can reduce risks so seed discolouration associated with ascochyta blight;
• botrytis grey mould is generally a low risk and manageable disease in Victoria; and
• timely harvest is critical to maintain the green seed colour.

Should I grow a 'green' lentil?

There are a number a number of production, storage and marketing issues growers need to consider with green lentils:

• Visual appearance of seed is critical. Good disease and insect control and timely harvest is required. Where possible growers should target production in environments where there is a lower risk of extreme climatic events, such as frost or heat, which can affect seed quality resulting in issues like wrinkled seed coat and bleaching.
• Understand marketing opportunities. Production in Australia is new and areas grown small. It is essential that growers have the capability for on farm storage and are aware of where the grain can be sold.
• Increased early vigour and higher biomass. The green lentils tend to reach canopy closure earlier and the plant type is more prone to lodging, so it is critical to ensure preventative fungicides are applied earlier to ensure effective canopy penetration. Consider sowing into standing stubble and in higher rainfall more favourable environments, a slight delay in sowing time and reduction in seeding rate, may prove beneficial.
• Green lentils offer alternate weed management opportunities. While they do not have the XT herbicide technology, their larger plant size is more competitive with weeds and larger seed size is well suited to the post harvest removal of smaller weed seeds.

Herbicide tolerant pulses

Improved weed control in lentil

Research by SPA and PBA has focused on improving Group B herbicide tolerance in lentil. Group B herbicides (including Imidazolinone (Imi) and Sulfonyl Ureas (SU)) applied in cereal phases of the crop rotation can aid weed control across the whole farming system due to their residual activity. However, their use can also reduce subsequent pulse production, particularly on alkaline, high pH, light textured soils where their residual life is often extended. Two lentil varieties, PBA Herald XT and PBA Hurricane XT are now commercially available with a permit allowing the post-emergent use of Imazethapyr. Previous research by SPA has demonstrated the tolerance to Imazethapyr and relative tolerance to other Imi’s. More recently, 2013 and 2014, research has explored the potential benefits of improved residual tolerance. Trials were set up at various locations across South Australia and Victoria to simulate residual Group B herbicide carry-over through the application of treatments at either very low rates post sowing pre-emergent (PSPE) or commercial rates pre-sowing in autumn (Figure 1).

Key findings from the agronomic herbicide trials:

• Response of lentils to herbicide treatments varied with seasonal conditions, method of herbicide incorporation, stubble coverage, soil texture and fertility.
• XT lentil varieties showed improved tolerance compared to conventional lentil varieties to all treatments, however they still incurred yield loss to some chemistries under certain conditions, indicating low safety margins to these chemistries (Figure 1).
• Chlorsulfuron and triasulfuron were the most damaging treatments in the trials. Metsulfuron was found to be the safest of the SU chemistries tested.
• It is important to note that all existing product label rates, plant-back periods and directions for use must still be adhered to. Further research is required to identify if sufficient crop safety exists in XT lentils to seek changes to label recommendations for other Group B herbicides.

Figure 1. Effect of various Group B chemistries and application rates on grain yield of PBA HurricaneXT and PBA Flash, Curyo, 2014. 'Residual' treatments were applied on the 15th of April, PSPE treatments were applied on the 19th of May. 

Bright future for weed control in pulses

Building on the success of the lentil research, the SARDI pre-breeding project has developed Group B tolerant faba bean and Group C tolerant lentil germplasm. Agronomic field trials in SA in 2014 confirmed faba bean lines with tolerance to a range of Imi chemistries and early generation PBA yield trials have identified lines with good adaptation to southern Australia. Preliminary field validation trials also confirmed a very high level of metribuzin tolerance, 10 to 20 times, in lentil germplasm. This material has now been ‘crossed’ with the Group B tolerant lines with the aim of developing dual herbicide tolerant (Group B+C) varieties. The project is now expanding into the development of novel herbicide tolerance in both kabuli and desi chickpea.

Expanding faba bean production areas

HRZ grows

Faba beans have continued to produce excellent and profitable yields in the higher rainfall zone of south western Victoria. In 2012 and 2013 SPA trials, gross margins between $1000/ha and $2000/ha were achieved, based on management costs of $250/ha and grain price at $400/t. Growers are also benefiting from the system benefits related to improved weed control options, breaking the cereal disease cycle and reduced fertiliser nitrogen costs. The new variety, PBA Samira, is likely to encourage further expansion, dispalying excellent yields in the HRZ (generally 8-10% greater than current varieties), wide adaptation and very good ascochyta resistance. Excellent disease resistance and later flowering mean it can take advantage of late rainfall in longer season environments. Seed is a similar size to Fiesta and Farah and is suited to Middle East markets. It has excellent ascochyta resistance and improved resistance to chocolate spot and rust compared to Fiesta and Farah.

Potential in the Mallee

In line with increasing interest in faba beans throughout the dryer cropping regions, SPA has been conducting a series of agronomic trials at the southern Mallee trial site. Yields of beans averaged 2.8 t/ha in 2013, the highest of all pulse crops on site that year, about 10% greater than lentils and 70% higher than chickpeas. In 2014, profitable yields of above 1 t/ha were still achieved, despite the dry season (similar to lentils) and the crop being affected by frost and ‘brackling’ (previously known as ‘necking’) (Tables 1 and 2). The results also highlighted the potential of several new breeding lines and the adaptability of beans to a range of row space configurations.

In dryer regions like the Mallee ‘brackling’ can occur, where the faba bean plant remains erect but a proportion of the stem ‘bracks’ over between 90 and 180 degrees. This phenomenon is thought to be due to moisture stressed plants being subjected to heat and wind events during the reproductive phase. Variation in variety susceptibility/resistance to brackling has been observed and PBA are aiming to improve resistance in the future.

Table 1. Grain yield (t/ha) of faba bean varieties grown at Curyo in 2014 in various row spacings.

lsd(P<0.05)_RSxVar = NS; lsd(P<0.05)_Var = 0.18; lsd(P<0.05)_RS = NS

Table 2. Gross margins of faba bean varieties grown at Curyo in 2014 in various row spacings, based on production costs of $200/ha and grain returns of $420/t. 

Medium seed sized kabuli chickpeas deliver profit

While grain yield is important in chickpeas, overall grain size and the proportion of seed within each size category for kabulis is critical determining the potential profitability of a variety. More recently it has been apparent that the smaller sized kabulis, like Genesis 090 can be difficult to market, particularly when there is oversupply in the world market. Medium and large kabulis potentially can offer growers greater returns and ease of marketing provided grain yields are similar to the traditional smaller varieties and a high proportion of larger seed is achieved. Various field trials were conducted in the Wimmera and southern Mallee of Victoria from 2012-2014 aiming to determine the optimum sowing date, row spacing and disease management for chickpeas, particularly focussing on the medium sized kabulis.

Key findings from the trials include:

• Agronomic trials conducted in 2012 and 13 demonstrated the benefits of increased seed size on potential profitability of kabuli chickpeas. The net income of from PBA Monarch, a new medium sized kabuli, was about $70/ha/annum and $200/ha/annum greater than Genesis 090A and more than double the desi, PBA Striker in the Wimmera and southern Mallee, respectively, even though grain yields were similar (Figure 2). This was primarily due to a greater proportion of seed in the 8-9 mm and 9-10mm categories than Genesis 090A (Figure 2). Seed in these categories receives $200-$300/t more than the 7-8mm category. It is also anticipated that seed in the 8-9mm and 9-10mm categories will be easier to market, preventing the need for growers to store seed on farm for long periods, as has been the recent history for Genesis 090.
• Further research in 2014 indicated there is potential to continue improving profitability of kabuli chickpea, with one breeding line showing improved profitability over PBA Monarch (Figure 3). It also highlighted the importance of assessing understand seed size distribution to maximise returns for growers, with some lines showing potentially high yields, but smaller seed size, resulting in lower returns.
• The larger seeded varieties like Genesis Kalkee are likely to be a viable option in medium rainfall environments like the Wimmera, but do not appear to have the yield stability required to be consistently produced in dry areas such as the southern Mallee.
• Other agronomic lessons included:
  • Using the most appropriate disease management package for the variety as recommended on the brochure is essential to maintain profitability.
  • Delaying sowing in the southern Mallee always resulted in losses; up to $450/ha in comparison with sowing the first week of May.
  • Chickpeas appear to be widely adaptable to a range of row spacing with no difference observed from 18cm to 72cm in the trial in 2013.

Figure 2. Average grain yield, net income and seed size distribution of representative kabuli chickpeas in comparison with the desi PBA Striker, grown in the Wimmera (2012-13) and southern Mallee (2012-14) of Victoria. Note. Net income based on the following grain prices: Desi = $450/t; Kabuli = <7mm-$330, 7-8mm-$550, 8-9mm-$750, 9-10mm-$850, 10-11mm-$1000 with fixed management costs of $220/ha and fungicides at $15/ha per application (No. of sprays based on varietal resistance: resistant (Genesis 090) = 1, moderately resistant (PBA Striker) = 2, moderately susceptible (PBA Monarch and Kalkee) = 3 southern Mallee and 6 in Wimmera).

Figure 3. Average grain yield, gross margin and seed size distribution of kabuli chickpeas in comparison with the desi PBA Striker, grown in the southern Mallee (2014) an southern Mallee of Victoria.

Contact details

PB Bag 260 Horsham, Vic, 3401
0409 357 076
jason.brand@dedjtr.vic.gov.au
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