Pulse performance and agronomy update

Take home messages

• High prices and recent production successes in some pulse crops continue to drive area expansion and interest in these crops.
• Lentil expansion into higher rainfall and lower rainfall regions needs to be based on sound paddock selection, agronomic management, variety choice and long term crop yield performance.
• Variety choice in lentils provides a range of options to combat disease, soil constraints and herbicide residues, providing reduced production risk opportunities for growers. PBA Jumbo2 remains the highest yielding variety and has a high level of disease resistance which improves grower returns over existing varieties in many areas.
• Recent faba bean variety releases, PBA Samira and PBA Zahra, had superior yields and improved disease resistance over older varieties in 2016.
• Early sowing in favourable pulse producing regions was less beneficial in 2016 than in previous drier years.
• All chickpea varieties now require multiple effective foliar fungicide sprays, along with a sound disease management strategy to control ascochyta blight (AB). Careful consideration and planning are required before deciding to grow this crop in SA in 2017 regardless of price on offer.

Pulse expansion

Area sown to pulses in SA reached record levels in 2016 with more than 450,000ha sown, an increase of 30% on the five year average (Primary Industries and Regions SA (PIRSA) Crop estimates Nov 2016). Lentils were again the dominant crop of choice representing close to 40% of the total area sown. Due to the favourable and long season, final production figures are still being compiled at the time of writing, but early PIRSA estimates predicted a grain crop in excess of 750,000t, some 60% higher than the five year average. This is a clear example that the industry has matured in this state and through an effective combination of breeding, agronomy, marketing and extension has been able to capitalise on the favourable production season unlike in similar climatic years of the late 1990s and early 2000s. For the second time in three years, pulses were favoured by cool spring conditions but unlike in 2014, rainfall was generally above average during this period last year leading to very high yields. Disease, waterlogging, localised frost, heavy rain combined with strong winds and hail were all limitations to yield, but generally pulses performed well above long term averages and expectations. However, there were some cases of below average yields or even complete crop failure mainly due to severe weather events and/or flooding damage, but virus diseases, weeds and chemical damage were also responsible in a few situations. Continued successful expansion of the pulse area in SA will rely on careful and sensible paddock selection, combined with appropriate crop choice and sound timely agronomic practice including variety selection. Yield and gross margin expectations need to be realistic with long term average crop performances in any given area and not just based on 2016 results and grain prices.

Lentil-mania

The lentil area in SA increased again in 2016 with a record 160,000ha estimated to be sown. This figure is some 60% above the five year average and a record production of over 250,000t is expected. Lentils continue to be grown at high intensities (10-40% of total crop) in traditional producing areas such as the Yorke Peninsula and the Adelaide Plains in the lower Mid North, but has also expanded into new production areas with a number of growers attempting this crop for the first time last year. Relative high prices, production success stories from previous years and the availability of disease resistant and herbicide tolerant varieties have driven the increase in area, particularly into low rainfall regions. However, a strategic and well planned approach based on prudent soil type and paddock selection, sound and timely agronomic management and correct variety choice has been and will continue to be required to reduce production risks and help ensure profitable crops in these areas.

Be realistic in the low rainfall

Significant lentil production occurred in low rainfall areas in 2016 with more than 10,000ha of production estimated across the Upper and Eastern Eyre Peninsula, Upper Mid North and Mallee districts of SA. In most cases, production was successful with yields generally ranging from 0.7t/ha to more than 3t/ha. The availability of the variety PBA Hurricane XT with improved tolerance to Group B residual herbicides has greatly improved the ease of production in these areas and is a popular choice for this reason. PBA Bolt with improved tolerance to boron and salinity and improved harvestability over many other varieties has also been popular, but both these varieties require fungicide protection for botrytis grey mould (BGM), which is not normally a problem in these areas but present in many crops last year. PBA Jumbo2 is the highest yielding lentil variety in SA in all trials where the average site mean yield has been greater than 1t/ha. It has a very high level of disease resistance, making it a popular choice for these areas when soil toxicity and herbicide constraints are not seen as significant issues.

Despite improved varieties and numerous success stories in low rainfall areas in 2016, growers are urged to proceed with caution with lentil expansion as the crop is still inherently poorly adapted to the hostile soils and the frosty, dry seasons which occur regularly in these regions. At Lameroo, lentil yields from 2005-2015 averaged just over 0.9t/ha, with a number of low yields (four years below 0.4t/ha) and a high of 2.2t/ha (Table 1). Reproductive frost damage, post flowering moisture stress and high temperatures during the flowering and pod filling period were the most common factors reducing yields over this period — high prices and current new varieties will have little impact on reducing the effect of these stresses on crop performance. While no results are available from Lameroo in 2016 for direct comparison with this data set, trials in the Mallee areas of Victoria last year ranged from 2.0 to 3.4t/ha, indicating the highly favourable nature of last season and the very much above average yields achieved in the Mallee areas. High lentil grain prices can buffer low yields to some extent, but realistic grain yields and prices based on long term averages must be used along with appropriate agronomic cost inputs for achieving a marketable product prior to deciding to grow lentils in low rainfall areas. Using yields and/or prices based on favourable years only is fraught with danger. The ability to complete lentil harvest timely and store grain on-farm must also be considered when growing lentils as seed quality is quickly reduced by rain events on the mature grain.

YLFs (Yield limiting factors): de = preflowering moisture stress, dl = post flowering moisture stress, phwd = pre-harvest weather damage, fr = reproductive frost damage, w = weed competition, transient waterlogging, ht = high temperatures during flowering/podfill, hd = residual herbicide damage.

And cautious in the high rainfall

Expansion of lentil production into high rainfall areas has had mixed results over the past two years. In 2015, many lentil crops grown in traditional faba bean producing paddocks fared well with average winter and below average spring rainfall totals. Average to above average yields were achieved and this combined with very high grain prices led to some exceptional returns to growers. In 2016, a return to average or above average rainfall amounts led to waterlogging and in extreme cases, flooding. Lentils have a very low tolerance for waterlogging and anaerobic conditions compared with cereals. Vegetative growth and root development are severely depressed and in many cases plants will die and even if plant survival occurs, grain production and potentially nitrogen (N) fixation will be severely reduced. Many parts of lentil paddocks or in severe cases whole paddocks were lost in the higher rainfall areas of SA in 2016 despite good performance on similar paddocks in 2015. If sowing lentils in high rainfall areas in 2017, the potential for crop failure in wet seasons must be carefully considered and restrict sowing to the better structured and well drained paddocks.

And alert and responsive in the intense lentil areas

PBA Hurricane XT has moderate resistance to foliar ascochyta blight (AB) and does not require fungicide sprays if disease is not visible. In 2015 and 2016, low levels of AB infection were identified in a number of paddocks of this variety. Growers are urged to monitor crops regularly for disease, and podding sprays may be required if disease is present during the growing season. The rapid and dominant uptake of PBA Hurricane XT, particularly on the Yorke Peninsula, threatens the longevity of the AB resistance in this variety and potentially others. It is important to diversify variety selections within a year and across rotations, alongside agronomic and disease management practices to maintain the sustainability of the system and reduce the risk of genetic resistance breakdown and crop yield loss.

BGM has reduced lentil yields by varying levels in five of the past seven years in parts of SA including last year where a severe disease outbreak occurred. This disease is now a major consideration when determining variety choice in disease prone areas of SA to reduce production risks and make crop management easier. The six SA National Variety Trials (NVT)  in 2016 (Yeelanna, Minlaton, Maitland, Willamulka, Laura and Riverton) were sprayed with fungicides as per commercial practice and had nil to low levels of BGM present, however the four Pulse Breeding Australia (PBA) trials (Melton, Kadina, Snowtown and Mallala) had no sprays applied and BGM infection was high to severe at all sites. The relative similar level of infection between sites within these two groupings (disease managed and disease not managed) allows for a comparison of variety performance with and without disease pressure (Figure 1).

Figure 1. Relative grain yield performance (expressed as a % of group mean) of eight lentil varieties and seven PBA breeding lines from a group of six 2016 SA NVT trials (BGM disease managed) and a group of four SA PBA trials (BGM not managed).

Varieties with values higher on the Y-axis performed better when disease was controlled and varieties with higher relative yields on the X-axis performed better under high BGM disease pressure. The R² value indicates there was no significant correlation between variety performance with or without disease. For example, Nipper was relatively high performing when disease was not controlled but comparatively low yielding when disease was controlled. Conversely, CIPAL1301, a PBA Bolt replacement for low yielding areas, was high yielding when disease was controlled but like PBA Bolt does not possess high levels of resistance to BGM and this will need to be managed in disease prone environments. The standout variety in this analysis is PBA Jumbo2 which shows high yields in both environments and a very large improvement over Nugget, the variety industry was growing when the last severe BGM outbreak occurred in 2001. The other promising development is the improvement of CIPAL1422 (a medium seed sized XT red lentil) over PBA Hurricane XT in environments with high disease intensity, but a similar performance to this variety when disease was not a factor. Both CIPAL1301 and CIPAL1422 are anticipated in being available for 2018 sowings.

Australian lentil production is dominated by red lentils similar to the very large Canadian industry, however internationally there are significant green (yellow cotyledon) lentil markets. There is also a small domestic market for these types. The Australian green lentil industry is currently in its infancy, but its existence may allow some growers to spread their production and marketing risks, particularly if world red lentil production trends continue to produce large red lentil stocks. PBA Greenfield (medium sized) and PBA Giant (large) are better adapted than Boomer, in particular the former has an agronomic performance very similar to the major red lentil varieties in SA providing a good opportunity if markets can be captured. Green lentils are consumed whole and seed quality is imperative. If considering green lentil production, growers need to be aware of a number of production, storage and marketing issues with green lentils and should seek advice from an experienced lentil agronomist.

Chickpeas — to grow or not to grow?

Current very high prices for chickpeas are creating a great deal of interest in growing this crop in 2017. Chickpeas are generally less suited than other pulse crop options to many of SA’s cropping regions due to their relative later maturity, poorer weed competitiveness and increased sensitivity to cold temperatures during the flowering and pod filling phase. Complicating this further is the recent change in the AB pathogen virulence in this crop in southern Australia. This change now means that all commercial varieties are rated as susceptible (S) or moderately susceptible (MS) to AB and will incur yield loss under disease pressure if AB is not effectively controlled (Table 2). Growers considering sowing chickpeas in southern Australia in 2017 need to be prepared to spray all crops multiple times with an effective foliar fungicide regardless of variety grown. However, varieties rated MS will have a lower production risk than those rated S and fewer fungicides may be needed in some years.

Successful chickpea crops were grown in SA under the disease conducive conditions of 2016, however a number of crops also incurred high levels of foliar disease yield loss and seed staining. In many of these latter cases, it was noted that one or more of the following occurred:

• An appropriate seed dressing was not applied.
• The first foliar disease application was applied around 10-12 weeks after sowing instead of the recommended 6-8 weeks post sowing.
• Foliar fungicide rates of chlorothalonil (720g a.i/L) used were often less than 1.0L/ha.
• Foliar fungicide application occurred after significant rainfall events, rather than prior to them.

Chickpea growers must now carefully consider their risk to AB infection along with their ability (logistically and financially) to effectively control the disease prior to choosing to grow this crop in southern Australia regardless of price offered. This will be the case in both high and low rainfall regions as severe disease outbreaks can still occur in the latter in all current varieties during wet seasons such as 2016. PBA chickpea is continuing to develop varieties with higher and more robust levels of AB disease resistance as a matter of priority and several lines with improved resistance levels over Genesis™ 090 were identified from the 2016 season.

Faba beans — king pulse of the wet

The yield performance of faba beans was high and above average in 2016 with NVT and PBA trial average yields generally ranging from 3-6t/ha across southern Australia. Faba beans handle waterlogging and reproductive frost events better than all other pulse options and remain the crop of choice in higher rainfall environments despite relative lower prices in 2016. Excessive growth and lodging were again an issue in early sown crops in 2016, encouraged by the favourable and long growing season and work continues to identify genotypes and agronomic strategies better suited to this favoured agronomic practice in beans. The disease performance of faba bean varieties has been covered in the pulse disease article elsewhere in this publication, but yield results from 2016 highlight the improved yield (approximately 10% across all trials) and superior seed quality of new faba bean varieties, PBA Samira and PBA Zahra, over older varieties. These new varieties continue to reduce the risk of faba bean production in wet growing seasons such as 2016.

Sowing time in pulses — 2016 performance

The southern region pulse agronomy program continues to evaluate pulse varieties under conventional and earlier than conventional sowing times in SA. This is to both understand the plant traits of importance for this practice in the various pulse species, as well as to identify varieties more suited to modern farming systems where this practice is now preferred partly to mitigate yield losses in dry seasons. Results are still being compiled and analysed at the time of this article going to print, but preliminary analysis indicates that lentil and chickpeas were generally less favoured by early sowing dates at Pinery and Melton in 2016 than in previous years, however faba beans at Hart continued to perform better at mid April dates than early May and mid May sowing dates. Excessive biomass production leading to premature lodging, flower and pod shading, increased foliar disease pressure and cool early spring temperatures were reasons identified for the lack of sowing date response in pulse crops sown in early May in the more favourable areas of SA last year. These issues, along with the benefits of sowing pulses early, need to be considered when employing this practice, particularly in favourable production regions and when using high biomass producing and/or disease susceptible varieties.

Acknowledgements

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.

This research was also funded by SARDI and DEDJTR (DAV00150). Thanks to the SARDI New Variety Agronomy teams at Clare, Pt Lincoln, Waite and Struan, SARDI Pulse Pathology team, Waite for data collection and trial management and to all our grower collaborators for the use of their land.

Contact details

Larn McMurray, SARDI Clare
08 8842 6265
larn.mcmurray@sa.gov.au