Storing Pulses

Grain Storage chicpea silo

Storing pulses successfully requires a balance between ideal harvest and storage conditions. Harvesting at 14 per cent moisture content captures grain quality and reduces mechanical damage to the seed but requires careful management to avoid deterioration during storage.


  • Pulses stored above 12 per cent moisture content require aeration cooling to maintain quality.
  • Meticulous hygiene and aeration cooling are the first lines of defence against pest incursion.
  • Fumigation is the only option available to control pests in stored pulses, which requires a gas-tight, sealable storage.
  • Avoiding mechanical damage to pulse seeds will maintain market quality, seed viability and be less attractive to insect pests.

Quality characteristics


Pulse crops most commonly grown in Australia include broad beans, faba beans, chickpeas, field peas, lentils, lupins, vetch and mungbeans.

Many of the quality characteristics of the grain from these crops are in the appearance, size and physical integrity of the seed. Mechanical seed damage, discolouration, disease, insect damage, split or small seeds will downgrade quality and market value.

Buyers prefer large, consistently-sized seed free of chemical residues for easy processing and marketing to consumers.

Optimum moisture and temperature

Research has shown that harvesting pulses at higher moisture content (up to 14 per cent) reduces field mould, mechanical damage to the seed, splitting and preserves seed viability. The challenge is to maintain this quality during storage as there is an increased risk of deterioration at these moisture levels. As a result, pulses stored above 12 per cent moisture content require aeration cooling to maintain quality.

Grain Trade Australia (GTA) sets a maximum moisture limit of 14 per cent for most pulses but bulk handlers may have receival requirements as low as 12 per cent. As a general rule of thumb, the higher the moisture content, the lower the temperature required to maintain seed quality (see Table 1).

Green pods and grains increase the risk of mould developing during storage — even at lower moisture content. Aeration cooling will help prevent mould and hot spots by creating uniform conditions throughout the grain bulk.

Table 1 maximum recomended storage period

Weather damage hinders storage

Pulses exposed to weathering before harvest deteriorate more quickly in storage. Chickpeas stored for the medium to long term (6–12 months) continue to age and lose quality
(see Table 2). Growers can minimise the effects of seed darkening, declining germination and reduced seed vigour by:

  • Lowering moisture content and temperature
  • Harvesting before weather damages the grain.

Table 2 - storage life of chickpeas

Aeration cooling — vital tool

Aeration cooling:

  • Creates uniform conditions throughout the grain bulk.
  • Prevents moisture migration.
  • Maintains seed viability (germination and vigour).
  • Reduces mould growth.
  • Lengthens (and in some instances stops) insect reproduction cycles.
  •  Slows seed coat darkening and quality loss.

Aeration cooling allows for longer-term storage of low-moisture grain by creating desirable conditions for the grain and undesirable conditions for mould and pests. Unlike aeration drying, aeration cooling can be achieved with air-flow rates of as little as 2–3 litres per second per tonne of grain.

High-moisture grain can also be safely held for a short time with aeration cooling before blending or drying. Run fans continuously to prevent self heating and quality damage.

Be aware that small seeds such  as lentils will reduce the aeration fan capacity as there is less space for air to flow between the grains. For information on aeration cooling management, refer to the GRDC fact sheet, Aeration cooling for pest control.


Aeration drying

Pulses stored for longer than three months at high moisture content  (>14 per cent) will require drying or blending to maintain seed quality. Aeration drying has a lower risk of cracking and damaging pulses, which can occur with hot-air dryers.

Unlike aeration cooling, drying requires high airflow rates of at least 15–25 l/s/t and careful management. For more information on aeration drying refer to the GRDC booklet, Aerating stored grain, cooling or drying for quality control.

Handle with care

In addition to harvesting at high moisture content, growers can manage seeds quality at harvest by:

  • Minimising the number of times augers shift grain.
  • Ensuring augers are full of grain and operated at slow speeds.
  • Checking auger flight clearance — optimum clearance between flight and tube is half the grain size to minimise grain lodging and damage.
  • Operating augers as close as possible to their optimal efficiency — usually an angle of 30 degrees.
  • Using a belt conveyor instead of an auger where possible.

Silos fit the bill

Keep-it-safe-in-silosSilos are the ideal storage option for pulses, especially if they are cone based for easy out-loading with minimal seed damage. For anything more than short-term storage (3 months) aeration cooling and gas-tight sealable storage suitable for fumigation are essential features for best management quality control.

Always fill and empty silos from the centre holes. This is especially important with pulses because most have a high bulk density. Loading or out-loading off-centre will put uneven weight on the structure and cause it to collapse. Avoid storing lentils in silos with horizontally corrugated walls as the grain can run out from the bottom first and collapse the silo as the grain bulk slides down the silo walls.

Pests and control options


The most common pulse pests are the cowpea weevil (Callosobruchus spp.) and pea weevil (Bruchids pisorum). The cowpea weevil has a short life span of 10–12 days while the pea weevil only breeds one generation per year.

The only control options are phosphine, an alternative fumigant or controlled atmosphere, all of which require a gas-tight, sealable storage to control the insects at all life stages.

For more information refer to the GRDC booklet, Fumigating with phosphine, other fumigants and controlled atmospheres.

Chemical sprays are not registered for pulses in any State. While there is a maximum residue limit (MRL) for dichlorvos on lentils, the product is only registered for use on cereal grains.

Weevil development ceases at temperatures below 20°C. This is a strong incentive for aeration cooling, especially if gas-tight storage is not available.

Keep it clean

Clean-Sweep-Cleaning-MachineryThe first line of defence against grain pests is before the pulses enter storage — meticulous grain hygiene. Because pest control options are limited, it’s critical to remove pests from the storage site before harvest.

Cleaning silos and storages thoroughly and removing spilt and leftover grain removes the feed source and harbour for insect pests.

Clean the following areas thoroughly: 

  • Empty silos and grain storages
  • Augers and conveyers
  • Harvesters
  • Field and chaser bins
  • Spilt grain around grain storages
  • Leftover bags of grain

Chemicals used for structural treatments do not list the specific use before storing pulses on their labels and MRLs in pulses for those products are either extremely low or nil.

Using chemicals even as structural treatments risks exceeding the MRL so is not recommended.

Using diatomaceous earth (DE) as a structural treatment is possible but wash and dry the storage and equipment before using for pulses. This will ensure the DE doesn’t discolour the grain surface.

If unsure, check with the grain buyer before using any product that will come in contact with the stored grain. For more information see the GRDC fact sheet, Hygiene and structural treatments for grain storages.

DPI&F note: Grain Storage Identification of insect pests

stored grain pest mites

Grain Storage Identification of insect pests

Ken Bullen, DPI&F, Plant Science, Toowoomba, Qld..

Why identify stored grain pests ?

Most insect control methods for stored grain work against all species. So you don’t need to identify the storage pests to make decisions about most control methods. But if you intend spraying grain with insecticides you may need to know which species are present if:

  • a previous application has failed and you want to know whether resistance was the reason – if more than one species survived, resistance is unlikely to be the cause
  • you intend using a residual protectant to treat infested grain – pyrimiphos-methyl, fenitrothion and chlorpyrifos-methyl are ineffective against lesser grain borer, and pyrimiphos-methyl and fenitrothion are generally ineffective against sawtoothed grain beetle
  • you intend using dichlorvos to treat infested grain – if lesser grain borer is present you need to apply the higher dose rate Insecticide sprays are not registered for oilseeds and pulses, so identification of pests in those grains is not so important.

Common species

Cereal grains

Cereal grains include wheat, barley, oats, triticale, sorghum and millets. The most common insect pests of stored cereal grains in Australia are:

  • Weevils: (Sitophilus spp.). Rice weevil is the most common weevil in wheat in Australia
  • Lesser Grain Borer: (Rhyzopertha dominica)
  • Rust Red Flour Beetle: (Tribolium spp.) • Sawtooth Grain Beetle: (Oryzaephilus spp.)
  • Flat Grain Beetle: (Cryptolestes spp.). See images in this DPI&F Note. Another dozen or so beetles, moths, psocids (booklice), and mites are sometimes present as pests in stored cereal grain.


Oilseeds include canola, linseed, safflower and sunflower. The most common pests in stored oilseeds are:

  • Flour beetles
  • Sawtoothed grain beetle
  • Moths of various species. See images in this DPI&F Note.


Pulses include: faba beans, chickpea, cowpea, field pea, mung bean, navy bean, soybean, pigeon pea. The most common insect pests of stored pulses are Bruchid beetles, and moths. See images in this DPI&F Note.


Weevils – the Rice weevil (Sitophilus oryzae) is the most common weevil in wheat in Australia. Major pest of whole cereal grain and some solid cereal products, eg, pasta. Destroys grain directly and through heating. Approx. length adult: 3.5 – 4.0mm; Life cycle: 25 days@30°C & 70% r.h., 25 days; Population growth up to 25 x in a month; Eggs laid singly in prepared hole in grain; develops concealed within the grains; Adults fly & walk long distances; adults can walk up glass surfaces. Resistances to protectant OP insecticides is rare, phosphine resistance widespread, no known resistance to dichlorvos; can not be controlled with phosphine in unsealed silos.

Lesser Grain Borer ID

Lesser grain borer (Rhyzopertha dominica). Major pest of whole cereal grains, most serious in hot dry conditions; Resistance to OP insecticides – common; head invisible when viewed from above; approx. adult length 2.5 – 3.0mm; resistance to phosphine fumigation, strong and widespread; resistance to methoprene protectant insecticide is increasing, susceptible to new spinosad insecticide (available in 2006-07), resistance to dichlorvos is common; adults bore through grains; max. population growth rate per month 20x; larvae lives concealed in grain or flour; adults are strong fliers.

Red Rust Flour Beetle

Red rust flour beetle (Tribolium castineum). Major pest of stored grains and milled products; approx. adult length 3.5=4.0mm; survives very dry conditions; max. population growth rate per month 70x; larvae not concealed in grains; adults strong fliers; resistance to protectant OP insecticides is rare, no known resistance to dichlorvos, strong resistance to phosphine fumigant found in C.Q.

Sawtooth Grain Beetle

Sawtooth grain beetle (Oryzaephilus surinamensis). Major pest of stored grains and other stored products; approx. adult length 3.0mm; max. population growth rate per month 50x; Strong resistance to phosphine found in D. Downs, strong resistance to protectant OP insecticides is common, no known resistance yet to dichlorvos; adult feeds, flies, and walks long distances; adults can walk up glass surfaces.

Flat Grain Beetle

Flat grain beetle (Cryptolestes spp.). Important pest of stored grains and other stored products; adults very flat, antennae very long and hair-like; approx. adult length 3.0mm;resistance to protectant OP insecticides is untested, strong resistance to phosphine fumigant on Darling Downs and in Biloela district; max. population growth rate per month 55x; adults long lived, feeds, flies and walks rapidly.

Psocids bookline

Psocids – or booklice (Liposcelis spp.). Pronounced ‘so-kids’; important pest in grain storages in Australia; very tiny – about 1.0mm long; infest a wide range of stored grains and other commodities; appear as a ‘moving carpet of dust’ on grain; thrive under warm moist conditions, max. population growth rate per month 25x. Life cycle 21 days under ideal conditions; ‘secondary’ feeders, living on damaged grain etc., can cause heating of grain; huge infestations spread to structures and cause worker discomfort; if protectant insecticides fail to control psocids, expert identification of species involved is advisable; For further detail refer to special DPI&F


Mites (various species). Common pests in stored grains; occur mostly in damp or moist grain; Mould mite or Lemon-scented mite (Tyrophagus putriscentiae) – very tiny, about 0.5mm long. Appear as a moving carpet of brown dust on grains, bags, structures and floors; large populations may emit a pungent smell; life cycle is 8-12 days under ideal conditions, max. population growth rate per month 500x; more conspicuous at high moisture mouldy conditions. Feeding damages grains, promotes mould growth, imparts an ‘off’ odour, and may cause severe discomfort and dermatitis in workers. Protectant OP and methoprene insecticides not effective; resistance to dichlorvos untested; no known resistance to new spinosad protectant insecticide (on market 2006-07). Phosphine fumigation will only be successful if done in sealed, gas-tight storages.

Indian Meal Moth
Indian Meal Moth
(Plodia interpunctella). adults’ wings are bicoloured cream & brown, length approx. 8.0-9.0mm, larvae creamy white, approx. 12mm long; major pest in flour mills, processing plants etc., webbing produced by larvae can block machinery; max. population growth rate per month 60x; adult does not feed; active at dusk and dawn.

Angoumois Grain Moth
Angoumois grain moth
(Citotroga cerealella), and grain damage. Smaller than other storage moth pests, adults 5.0-6.0mm long; pest of whole cereal grains, will attack grains before harvest, esp. maize. Infests only surface layer of bulk-stored grains, adult unable to penetrate deeply. Max. population growth rate per month 50x. Larvae develop concealed in a single grain; adult moth does not feed. No known resistance to protectant OP’s, or new spinosad insecticide. Not susceptible to methoprene.

Cowpea Soybean Bruchid
Cowpea Bruchid
(Callosobruchus spp) in mungbean & Soybean Bruchid (Bruchidius mackenzii) in soybean. Bruchids are a major and increasing pest of pulse crops in Australia. In Northern region, Cowpea bruchid is a major problem to the mungbean industry. Adults are small, about 3.0mm long, with a tear-shaped body. Eggs are easily visible, white and laid on surface of individual beans. Larvae develop within the seeds, from where they emerge as adults, leaving a perfectly round hole in seeds. Adults are strong fliers and lay about 100 eggs in their 10-12 day lifespan. The soybean bruchid is now becoming more widespread in the soybean industry.

NOTE: For more detail on bruchid pests, see ‘Bruchids in Mungbeans and Other Pulse Crops – A Major Threat to the Pulse Grains Industry’


  • Insect drawings used above sourced from Degesch America Inc..
  • Some text regarding species above was sourced from, ‘Insects of Stored Grain – A Pocket Reference’, David Rees, (1994), Stored Grains Research Laboratory, CSIRO Division of Entomology, GPO Box 1700, Canberra, ACT, 2601, Australia

Distinguishing between the common grain beetles

You can use a clean glass container as a simple test for identifying grain beetles. Put the live grain insects into a warm glass container (above 20oC so they are active, but not over 40oC or they will die). Weevils and sawtoothed grain beetles can walk up the walls of the glass easily, but flour beetles and lesser grain borer cannot. If you look closely at the insects walking up the glass, weevils have a curved snout at the front but sawtoothed grain beetles do not. Distinguishing between the species that can’t walk up the glass is more difficult. Lesser grain borers are cylindrical, dark brown and usually have their head tucked under their body.

Flour beetles and flat grain beetles are flatter, copper-brown, and their head usually protrudes in front of their body. Flat grain beetles are usually small, ant-like with long antennae. Flour beetles are larger with short antennae. Drawings of the common beetle pests and the steps in identifying them are shown on the next page. Most of the beetles other than the common species look something like the flour beetles, and should not be confused with the lesser grain borer if you know what the borer looks like.

Identification of common beetle pests of stored grain. Follow the steps from left to right

Identification of common beetle pest

Further information

You can find colour pictures and some information on insect pests of stored grain in:

  • ‘Insects of stored grain: a pocket reference’ by David Rees. CSIRO Division of Entomology (1994). The book is available from The Librarian, Stored Grain Research Laboratory, GPO Box 1700, Canberra ACT 2601, Tel 02 6246 4201, Fax 02 6246 4202.
  • ‘Insect pests of field crops in colour’ Queensland Department of Primary Industries Q18 3006 (1983). The book is available from DPI&F Client Service Centres
  • The entomology section of the AgWest web site
  • See the DPI&F Note ‘Grain Storage – Insect control in stored grain’, – for information on control methods.
  • ‘Bruchids in Mungbeans and other Pulse Crops – a Major Threat to the Pulse Grains Industry’, by Hugh Brier, Pat Collins, Phil Burrill and Mike Lucy, Ken Bullen, DPI&F.
  • DPI&F website  – for a comprehensive range of useful Notes on Grain Storage management on-farm
  • DPI&F Call Centre open from 8.00am to 6.00pm Monday to Friday (telephone 13 25 23 for the cost of a local call within Queensland; interstate callers 07 3404 6999) or email Or, phone one of the National Grain Storage Extension Team
    • Qld Peter Hughes or Ken Bullen 07 4688 1200
    • Qld Philip Burrill 07 4660 3620
    • Vic. Peter Botta 03 5761 1647
    • SA Peter Fulwood 08 8568 6422
    • WA Chris Newman 08 9366 2309
    • NSW John Cameron 02 9482 4930