Irrigated chickpea, lentil or faba bean
Phil Bowden, Pulse Australia
The 2016 winter pulse crop broke records at every turn across Australia, so what are the prospects for 2017? Pulse and canola production totalled 4 million and 4.1 million tonnes respectively, lentil production in South Australia and Victoria doubled that of 2015, and chickpea production in northern NSW and Qld increased by 50%.
The buoyant global prices on offer for pulses was driven by increased demand from India, Pakistan and Bangladesh following crop failures due to the lack of monsoon rains. Pulse Australia expects interest in pulses to again be significant in 2017, and that a similar area will be planted to pulses as lentil and chickpea prices remain attractive, particularly in comparison to depressed cereal prices.
This forecast is tempered with some uncertainty regarding the likely demand following a larger crop harvest on the sub-continent that is now in the final stages of harvest. A deficit in supply in India is still expected later in the year, that will see buyers looking to import more grain.
Pulse Australia recommends growers take a prudent approach to budgets for irrigated pulses as both production and price risk are likely to influence the 2017 crop. When making paddock selections, take into account the higher disease pressure experienced in many broadleaf crops in 2016, due to prolonged wet conditions in winter and spring.
In particular, sclerotinia stem rot, a common fungal disease of broadleaf crops such as canola, that has become more prevalent in chickpeas and lentils, had an impact on crop yields in many regions and must be considered when selecting paddocks for broadleaf crops in 2017 season and beyond.
Sclerotinia sclerotiorum, the fungus that causes sclerotinia stem rot, has a wide host range including many common broadleaf weed species and nearly all the broadleaf crops. Ideal conditions last season will have boosted inoculum levels in paddocks growing these crops and weeds. The main drivers of disease severity are the frequency and amount of late winter and spring rainfall, the length of crop flowering and how frequently a broadleaf crop has been grown in each paddock.
The survival structures of the pathogen are known as ‘sclerotes’ and can remain viable in the soil for as long as ten years. Many foliar pathogens of pulse crops also survive in old stubble residue, ready to release spores the following year to infect emerging crops. Avoid sowing new season pulse crops adjacent to last season’s pulse stubble.
Full or supplementary irrigation of chickpea is common in districts where chickpea is grown in rotation with other irrigated crops, such as cotton. Management requirements for irrigated chickpea are the same as for dryland, but their sensitivity to waterlogging, for even a short time, can result in severe losses, particularly if the crop is also under stress from herbicides or disease.
With the larger planted area in 2016, and being such a wet season, disease management was a problem for growers and it is expected that disease inoculum will be at high levels in soils and on retained stubble. Ascochyta, botrytis and sclerotinia all caused yield losses in 2016 and will need to be managed carefully in 2017. Ascochyta and botrytis spores can be carried on seed so be careful to source planting seed for planting from a disease free crop and use a suitable fungicide seed dressing.
Botrytis and sclerotinia both have wide host ranges, enabling a build-up of inoculum in paddocks. Fungicide treatments during the season need to give continuous protection to new growth, especially as the crop gets into the danger period in spring. Budget for 4–5 protective sprays around 2–3 weeks apart and be prepared to apply additional sprays, depending on the seasonal conditions.
An important aspect of growing chickpeas to get the full benefit for future rotation crops is proper rhizobia inoculation. Seed needs to be inoculated for every crop (Group N) and there are a variety of inoculum types available such as granular, freeze dried or the standard peat types that will suit different situations. Rhizobia bacteria are very sensitive to heat, acid soils and fungicidal seed treatments. Inoculation of the seed needs to be done immediately prior to sowing, after applying the fungicide treatment to the seed.
Using sprinkler irrigation equipment reduces the risk of waterlogging, even during flowering and pod-fill, however there may be a higher risk of foliar disease, e.g. botrytis grey mould and ascochyta blight, due to the increased irrigation frequency and leaf wetness.
Pre-irrigate to fill the moisture profile prior to planting chickpea crops, unless there has already been sufficient rainfall. Watering up is most effective in bed, row and sprinkler systems, but is not recommended for border-check layout unless soil moisture is insufficient to achieve a uniform germination.
As a general rule, irrigation of the emerged crop should start early when there is a deficit of between 30–40 mm and around 60–70% field capacity. Schedule irrigation using soil moisture indicators rather than the crop growth stage.
Time irrigation application to prevent moisture stress during flowering and podding and to reduce the impact of high temperatures on yield, quality and grain size. This is particularly important with large kabuli types. Chickpea is very sensitive to waterlogging during flowering and podding so great care is required to provide adequate soil moisture without causing waterlogging.
In furrow irrigation systems, water every second row to avoid waterlogging. Doubling up the number of siphons can increase water flow and reduce irrigation time. Aim to have watering completed in less than eight hours, and have good tail water drainage to avoid any waterlogging in the crop area. If in doubt, do not water.
There has been a massive increase in lentil production in southern Australia due to increased demand and higher prices. Mainly grown on the alkaline soils in South Australia and Victoria, there has been success in NSW on some acid soil types. Growers are more confident with the new herbicide tolerant lentil varieties that increase the weed management options in lentil crops, however it is a crop that needs careful management. The main market is for human consumption in the Middle East and the Sub-continent, so delivery standards are very tight and there are no secondary markets for lower quality grain. Lentil is generally considered a higher risk crop, compared to other pulses.
Control foliar diseases through careful paddock selection (avoiding recent pathogen inoculum), crop canopy management and strategic fungicide applications as required. High humidity and excessive rainfall during the growing season encourages vegetative growth, which limits yield and can reduce seed quality. High temperatures during flowering and pod-fill also reduce yields.
Irrigation of lentil is possible, but good drainage is essential because lentil plants do not tolerate waterlogging, particularly during early flowering. Even short periods of waterlogging can result in severe losses. Management requirements for irrigated lentil are the same as for dryland crops, with a greater emphasis on disease control as irrigated crops are more prone to the spread of foliar diseases due to the dense canopy and potentially prolonged leaf wetness after irrigation.
Salinity levels in irrigation water or the soil to be watered must be low. Lentil is one of the more sensitive field crops to salinity—almost as sensitive as green beans (Phaseolus vulgaris), which require irrigation water < 0.7 dS/m for nil yield reduction. A 10 per cent yield reduction is expected if the irrigation water measures 1.0 dS/m.
Irrigation may be economical if the system allows adequate drainage, there is good quality water available and the rotation with other winter and summer crops is managed well to reduce the risk of disease pressure. Some experienced lentil growers in the eastern Mallee regions of Victoria successfully use overhead irrigation however flood irrigation of lentil crops is not widely practiced in Australia because the risk of yield loss to waterlogging is considered to be high.
Harvest as soon as the crop is mature, as lentil crops can turn brittle once fully matured and can be prone to shattering, especially following summer rainfall. Dessication or windrowing can help avoid these harvest problems.
To maximise grain quality, handle the seed carefully and avoid equipment blockages. Harvest during cooler conditions to improve harvest efficiency and reduce the risk of fire.
Faba bean originated in the Middle East and are now an important food crop in China and many Mediterranean and African countries. Australia’s main market is Egypt for human consumption, but the demand in China for beans used as both human and stock food in increasing. As faba beans receive greater attention in the western world, because of the value in livestock nutrition and crop rotation, there will be increasing export potential for Australian grain.
Market prospects depend on the Egyptian crop as well as supplies from Europe, particularly France. Domestic market is stock feed, but increasing use for aquaculture pellets is expanding the market size. Prices are down at present due to the large crop in 2016 and good harvests in Europe, the preferred supplier into Egypt due to lower freight costs.
The major risks to faba bean are ascochyta blight, chocolate spot, plant viruses and occasionally, rust. No varieties are resistant to all fungal and virus diseases. The impact of fungal diseases on yield can be reduced through the strategic selection and use of fungicides and following best practice crop management, including maintaining a 500 m buffer between new crops and the previous year’s faba bean stubble, and eradicating volunteer plants over summer and autumn.
Faba bean crops respond well to irrigation in dry areas. Furrow irrigation is successful in southern irrigation areas with either pre-water and sow, or dry-sow and water-up, following similar guidelines to those recommended for chickpea crops. Sprinkler irrigation is ideal to minimise waterlogging, however there may be a need for greater disease control against chocolate spot, rust or ascochyta blight due to more frequent wet conditions.
To maximise yield potential, crops should be watered to produce maximum biomass, and not allowed to stress during flowering and pod-fill. The additional risk of foliar disease under irrigation must be taken into account, along with the risks associated with waterlogging, particularly after the commencement of flowering. Faba and broad bean are more sensitive to waterlogging during their reproductive stage (flowering and podding) so, if in doubt, do not water.
Note that faba bean is one of the more sensitive field crops to salinity, but not as sensitive as field beans (Phaseolus vulgaris).
Harvest on time, with a properly set-up header. Start when nearly all pods are black, but before stems become completely dry and black. If the header settings are correct, pods will thresh easily to yield clean, whole seeds with a minimum of splits and cracks.
More information about irrigating pulse crops can be found: