Growing lentils: lessons learnt from growing lentils in central and north west Victoria

Background

Lentils have been grown in Victoria since the early 1990s. Initially in the Wimmera and central/southern Mallee gradually progressing into some of the drier areas of the north-west. Cropping systems in Mallee environments have gone through significant change in the last 15 years with the adoption of no-till, stubble retention and early sowing. However in the early days, farms were heavily reliant on cereal production which resulted in declining production due to a number of agronomic issues like grass seed banks particularly brome, resistance, low nutrition and disease. Through farm consultation, innovative research and a need to manage agronomic risks, a significant level of skill and confidence has been acquired in the best management practices (BMP) of growing pulses like lentils. Mallee farmers now see crops like lentils, as a great profitable rotation opportunity now and in the future.

Results and discussion

Pre-crop planning strategy

What soil types can lentils be grown on?

Lentils grow best on your best performing loamy to clay loam soils. They don’t like wet feet, high salt or Boron levels or deep sands. Choose paddocks with no large stones or sticks. In areas of the Mallee and South Australia (SA) small stones are now managed using heavy rollers this has opened up these soil types to growing lentils. Ideally a pH of 6-7 will see lentils perform well. Consult your local adviser with respect to this. Look at grid sampling for pH and then vary rate lime applications.

How important is stubble management?

Yes very important particularly in the drier years. Lentils are a short to medium (30-50cm) growing pulses, so pods are closer to the soil surface. Stubble height helps lentils push up taller due to light interception. This in turn pushes the bottom flower up the plant. Southern pulse agronomy trials in SA and Victoria have shown significant yield gains when retaining standing stubble. Standing stubble also helps to hold the plant up and reduce lodging in the years with greater plant biomass improving overall harvest efficiency. See the GRDC funded southern pulse trials of Dr Jason Brand.

Where do lentils fit in crop rotations?

Lentils like most pulses, fit in as another grass break phase in cropping rotations. In terms of resistance management, lentils fit well due to the ability to crop top with a crop desiccant like Paraquat. There is also the opportunity, due to label changes, to strategically apply products like Sharpen for broadleaf weed seed set control.

IMI tolerant Hurricane lentils are readily grown in the Mallee and SA due to their fit in Clearfield^TM systems for management of brome grass.

Also like most pulses, lentils offer a disease break and nitrogen fixing opportunity. Rough rule of thumb figures are that lentils will increase the following cereal yields by 500kg – 800kg/ha in the Mallee environment.

How important is it to know previous herbicide history when growing lentils?

This is a key box to tick when planning to grow any pulse. Lentils are extremely susceptible to group B herbicides (except IT Hurricane). In the Mallee, due to alkaline soils, group B herbicides can persist and effect lentil yields for up to three to four years.

Lontrel™ carryover has become a hot topic amongst growers and advisers in the Mallee and Wimmera. Stubble retention results in the Lontrel™ residues carrying over on the previous crop stubble, as far back as two years prior. Rates as low as 70ml/ha have resulted in lentil yield reduction particularly after dry Spring/summers

Do I need to know paddock weed pressure or can I deal with most weeds in-crop?

It’s really important that previous cereal crops are monitored for hard to kill broadleaf weeds like clover, medic or fumitory. These weeds in particular are a concern when growing lentils. There are a few IBS pre-emergent broadleaf options available. Registered products for the control of broad leaf weeds include Terbyne®, Simazine, Diuron, Metribuzin. The choice of product will be determined by soil type, weed presence, label recommendations, seeding system, stubble level, variety. Current findings show that Hurricane is less tolerant to Metribuzin so rates must managed with caution.

For pre-emergent grass control at seeding, resistance levels must be understood. Registered pre-emergentent options include Trifluralin, Sakura®. Choice will be determined by resistance status, soil type, seeding system, stubble level.

Seeding and variety strategy

What variety will I grow?

There are a significant number of varieties to choose from today. It is a reflection of the level of funding provided by GRDC through researchers like Jason Brand and his southern pulse research. In the Mallee environment Bolt, Ace, Hurricane XT, Jumbo 2 and Flash are the varieties of choice. This decision will be made depending on seed availability (Jumbo 2 new release), soil type (Jumbo2, Bolt, Flash have improved tolerance to salt and boron), herbicide system (Hurricane XT can tolerate some Group B herbicides), disease pressure (Jumbo 2 have an excellent disease package), yield potential—see local national variety (NVT) trial data—and marketability (small red lentils like Hurricane go to a smaller market being Bangladesh = supply/demand pressures).

Research, recently presented at the 2016 GRDC Grains Research Update in Bendigo, has shown varieties will respond differently to heat shock regardless of moisture levels. Bolt was shown to handle heat s hock better than other current varieties. Future variety breeding selections will be for heat shock along with a number of other of traits like herbicide tolerance (Metribuzin).

In the Wagga and Yenda zones, varieties that have yielded well in NVT trials (as reported by NSW DPI at the 2016 Wagga Wagga GRDC Grains Research Update) have been Ace, Jumbo 2, Greenfield, Bolt and Hurricane (Group B residues?).

Do I need to inoculate lentils?

Yes most definitely with Group E/F particularly on acid soils where rhizobia are at risk of survival.

Is there any difference with slurry peat or dry peat inoculants?

This needs to be researched locally as success will be totally dependent on the inoculant quality, soil type, pH, time between sowing and rain and temperature during this time. Most Mallee farmers use peat slurry, however there are some growers sowing the quality granulated peat inoculants through their small seeder boxes. This saves a messy operation at sowing time. Refer to GRDC Inoculation Guide; Matt Denton.

Do not mix inoculants with fungicides/insecticides.

What’s the ideal sowing time to sow lentils?

Research and experience has shown that sowing from late April to the first week of May will give more consistent higher yields. Generally most Mallee farmers will sow lentils after canola and lupins just prior to a cereal program. Most will also seed peas last to spread break crop risks. See sowing time trials from NSW DPI, Yenda.

Does row spacing and seed rate make much of a difference to yield?

Row spacing does make a difference predominately due to the ability to manage inter-row stubble residue. From experience, 15inch is a maximum distance. Greater than this lentils are prone to lodge in more favourable seasons. GRDC funded southern pulse research also has shown yield increases at wider rows to 12inch.

Ideally seed rates should be aimed at 120plants/m². Current research from Dr Jason Brand has shown that there is an opportunity to reduce seed rates back to produce 80plants/m². It is not only important to weigh your seed source for yield but also to manage seed costs when lentils are priced at $1400 – 2000 per ton. For instance using current on-farm Hurricane seed weights from 2015 harvest gives a 2016 seeding rate of 25kg/ha.

What depth should I sow lentils at?

Ideally lentils should be sown at a similar depth to your wheat depth. However lentils can be sown down to 8cm to chase deeper moisture and to avoid IBS pre-emergent chemical damage. It’s important when seeding that the furrow is closed to avoid possible chemical damage.

Early in-crop management

How important is it to roll lentils?

Rolling enables flexi and draper fronts to sit on the soil surface when harvesting for greater efficiency and a better quality sample. Disc seeding systems generally provide a flat harvesting surface so may not be necessary with these systems. The timing for this operation is when the majority of the crop is close to the top of the press wheel furrow. BCG trial work has shown that we have some flexibility in this operation to fit in with weed control priorities. Rule of thumb is 3-5node. Rolling prior to this can, with some heavy rollers on sandy soils, push pre emergent herbicides into the row, resulting in possible damage to the crop.

In-crop herbicide options

Broadleaf weed control?

Talk to your adviser.

Brodalɸ will control small radish, mustard, turnip and give suppression of deadnettle and capeweed (need to be less than two leaf though).

ɸCheck label for recommended rate

Coverage is essential for Brodal® so 70–100L of water is required. Some yellowing of lentils will occur after the Brodal® application. Avoid frosty conditions as this will increase yellowing.

Broadstrike™ at 25gm/ha + Uptake™ at 0.5 per cent can be used as late radish or mustard/turnip seed set control. 75L water is advised and warm conditions. Yield loss can occur in dry springs. At these rates Hurricanes will tolerate Broadstrike™.

What are my grass control options?

Talk to your adviser.

Strategy will be dependent on grass spectrum and timing. Mallee growers have been commonly applying two grass sprays. 1st one early 1-2 leaf grasses for 1st flush, second after rolling and broadleaf operations have been completed.

Weed control timing

If I have rolled my paddock prior to weed control, will this have any effect on the timing of weed control?

10–12 days should elapse between rolling and spraying as rolling can result in a germination of weeds and rolling stresses weeds and crop.

Do I control broadleaf or grass weeds first?

Talk to your adviser.

Ideally Brodal® needs to be applied to smaller weeds first. However in high pressure situation's grass control would be a priority. If Brodal® has been applied first then wait 10-14 days before apply grass selective. If grasses controlled first then wait 7-10 days.

Insect control

What is common insect control practice in typical lentil growing areas?

Imidacloprid seed dressings are extremely important in the management of aphid transmitted viruses. In 2007 significant damage occurred in the Mallee due to virus infection. Nil crop seed was treated back then. Lesson learnt.

What other common insects need to be managed?

Just recently Bryobia and Mandilotus weevil is starting become a problem in stubble retention systems. It is possible that we may be selecting for these harder to kill insects. So monitoring is important early in crop.

Most importantly Etiella (lucerne seed moth) and Heliothis are key insect control boxes to tick.

Why?

Lentils go to human consumption markets and there is no tolerance of hole damage.

Spraying occurs first with the Etiella moth around flowering/early pod set, when moths are being trapped or netted. This is generally determined when pre-set growing degree days have been met using the SARDI Etiella modelling calculator.

Heliothisɸ is the next to monitor and manage. Quite often the Etiella insecticide deters any moth laying. However monitoring is still critical.

ɸHeliothis is now known as Helicoverpa

Sumi-alpha® and Trojan® are registered options and these can be piggy backedɸ with ascochyta fungicides if necessary.

ɸCompatability of products needs to be checked

Typical fungicide strategy

What is a typical fungicide strategy in the Mallee?

Difficult question to answer as this will be determined by variety, size of canopy, potential yield and weather conditions.

Rules of thumb for the Mallee

Best to apply BGM products prior to canopy closure

Bolt:Susceptible to grey mould so most likely in most years. However in 2015 nil applied.

Typical Product options

Carbendazim @ 500mls/ha or Procymidone, Chlorothalinol, Mancozeb

Ace, Hurricane - Unlikely, best to monitor

Jumbo 2 - Resistant so unlikely.

Vegetative - early podding for Ascochyta

Each paddock will need to be assessed on yield potential, variety and seasonal conditions.

Bolt, Hurricane - Need to be monitored. Possible in wet seasons with large canopies.

Typical Product options

Many options Chlorothalonil @ 1lt Ha with 100lts water, no wetter required.However check availability and price of alternatives.

Ace, Jumbo 2 - Resistant so not likely. However must monitor due to possible variety change in resistance status.

Note: The Nipper ascochyta resistance gene is breaking down so if Hurricane is grown in your area, monitor closely.

Can I piggy backɸ fungicides with grass selectives to reduce operation costs?

Fungicides are commonly piggy backed with grass selective herbicides. Be mindful that grass control can be reduced by around 10 per cent. In the Wimmera where ryegrass resistance to Clethodim is high, generally a fungicide is not added.

ɸCompatability of products needs to be checked

Nutrition

What would be considered a BMP nutrition strategy for lentils?

The best way to answer this is to know your local critical nutrient levels. In the Mallee and SA we are starting to see responses to nutrients like sulphur. With the common use of ammonium phosphate (AP) fertilisers more and more paddocks are coming up deficient. So a common strategy would be to either spread gypsum at 200-300kg/ha and seed with mono-ammonium phosphate (MAP) or a cereal starter fertiliser (be wary about too much N) or just sow with a single super phosphate (SSP); rates around the 60-70kg/ha are common, which will deliver enough phosphorus and sulphur for 1-1.2t/ha. Lentils are responsive to zinc. Note from 2015 experience. Even though Hurricane is reasonably tolerant to IMI herbicides, in 2015 they responded well to zinc particularly when previous crops had been treated with an IMI herbicide.

Late crop management operations

Do Mallee/ Wimmera lentil growers desiccate and croptop their crops?

Most years this is common practice. Croptopping for weed resistance is one key reason why lentils are being grown in these areas. Desiccation is more about confidence around harvest timing. When a crop is desiccated lentil growers know that harvesting the crop will be in 7 days' time.

What is the best harvester for lentils?

Lentils need to be harvested with a flexi or draper type front. Pods sit low to the ground so front needs to be set on the soil surface.

Resources

Lentil Production: Southern Region, Pulse Australia Website

NSW DPI, Weed control in winter crops 2015 pdf

GRDC Update paper:Agronomy and production of lentil in southern NSW 2016

GRDC Update paper: Pulse check 2015 - agronomy and variety update

GRDC Update paper: Improving lentil tolerance to heat stress

Ascochyta and botrytis management in lentils with pre and post emergent fungicides – Ag Consulting Company

GRDC Update paper: Lentil research in progress including herbicide tolerance in the pipeline

GRDC Update paper: Viruses in pulse crops in 2007

Mallee Sustainable Farming, Jason Brand: Pulses in the Mallee pdf

Pulse Australia: Annual Pulse Update, Feb 2014

GRDC Update Paper: New opportunities for pulses in the Mallee

Contact details

Rick Rundell-Gordon
all-AG Consulting & Tech Services
0448 104 326
rickrundellgordon@gmail.com