Proper faba bean storage management is important to prevent a grade decrease.
Faba bean is a large kernel crop, so it is difficult to condition and dry. Faba bean is considered dry at 16% moisture content, but safe long-term storage requires moisture contents below this figure.
Crops stored under cool, dry conditions can be stored for long periods, but as seed moisture or temperature rises, storage length becomes less. The drier and cooler the grain, the safer it is during storage. The target temperature for all grains is 15°C. To reduce cracking, always minimize drop distances when moving faba bean into storage.
Faba bean must be monitored closely in storage: the crop will be graded “sample” if more than 1% of seeds are heated or rotted, or if there is a musty, mouldy or unnatural odour.
Faba bean will also darken over time, causing it to be downgraded, so storage over one year is not recommended.
Stored pulses should be monitored regularly for hot spots and other changes in moisture and temperature, and for the presence of insects.
It’s important to be cautious of weed seed dockage or green materials (i.e. Canada thistle heads) from volunteer crops, as they can cause heating (hot spots) if you cannot not get proper air flow through the bin.
A variety of manual and automated systems are available to help keep track of seed condition.
If pulses require handling, they should be moved as little as possible, and handled gently to reduce chipping and splits. Use belt conveyors instead of augers. If using augers, run the auger full and at a reduce speeds. Use ladders on equipment to minimize the dropping of seed from more than a few feet.
Faba bean should not be cleaned or handled below –20˚ C because of the increased risk of chipping and peeling.
DRYING OR AERATING DOWN
Faba bean is often highly variable in maturity and moisture content; seeds from the lower pods are more mature and drier than those from the uppermost pods. Drying and conditioning must be done carefully, as high heat air dryer temperatures damage and “case harden” the outer seed coat.
Dry and condition slowly to allow moisture to move from the inner portions of the seed to the surface. Combination drying (heated air drying and natural air drying) works well for conditioning faba bean.
Faba beans should be dried at a maximum of 32°C and should be done in two stages if more than 5% moisture content is removed.
With a hot air dryer, dry bean seeds should be dried to within 2% of final moisture content and then tempered in an aeration bin for at least 6 hours.
Afterwards, they should be cooled to the outdoor seasonal temperature. The slowness of this process prevents cracking.
Resource: Improved Management of Stored Pulses, Research Update, August 2019, PAMI
MAKING THE GRADE
Grading is done by the Canadian Grain Commission. Through the harvest sample program, farmers have the opportunity to send in harvested samples to the Grain Commission for grading. This grade can be compared with local buyer grades and may assist in marketing.
Standard of quality, and degree of soundness based on maturity and colour.
Percentage of splits.
Damage (heated or rotted, mouldy, perforated damage and total %).
Foreign material (ergot, excreta, insect parts, Sclerotinia, Stones or shale and total %).
Dockage is not assessed on faba bean samples that meet the commercially clean specifications. Those samples which are clearly not commercially clean may consist of a visual assessment. If there is no doubt that a sample contains more than 0.2% of foreign material, then dockage will be assessed.
Dockage is assessed and recorded to the nearest 0.1%.
Dockage is any material intermixed with the grain, other than the grain, that must and can be separated from the parcel of grain before a grade can be assigned.
Dockage is assessed only on unprocessed samples (referred to as the uncleaned or dirty sample) and is assessed on the gross weight of the sample.
Dockage is removed by cleaning procedures and then assessed and recorded to the nearest 0.1%.
Slotted sieve cleaning equipment are used, depending on seed size.
Dockage is not reported for samples grading:
“Faba beans, Sample CW (class) Account Fireburnt”
“Faba beans, Sample Salvage”
“Faba beans, Sample Condemned”.
Primary samples are considered commercially clean when they contain no dockage material.
Colour is evaluated on the cleaned sample after the removal of damaged and split faba beans.
Reasonably good natural colour: Faba beans are moderately immature, with lightly adhered soil, moderately discoloured from storage or other natural causes, such as mottling.
Fair colour: Faba beans are immature but not green, have moderate amounts of adhered soil, or are otherwise moderately discoloured from natural causes, such as mottling.
Poor colour: Faba beans have a dark discolouration covering less than half of the hull, where there is no penetration of the cotyledon.
Sunburned or oxidation: Faba beans have undergone normal discolouration of the seed coats during storage. The colour varies from light tan to brown to very dark brown, depending on the duration and conditions of storage.
Immature: Faba beans are normal size and greenish, but not distinctly green.
Damaged faba beans: include blackened or cracked, sprouted, distinct immaturity, heat or mould damage, damaged by insects, distinctly deteriorated or discoloured by weather or by disease, or any other damage that seriously affects appearance or quality.
Blackened: Faba beans are blackened when their seed coats are very dark blue to black. These are considered under damaged.
Cracked seed coats: Faba beans with cracked seed coats are considered sound if the halves of the kernels are held firmly together and the beans are not otherwise damaged.
Discoloured: Faba beans are considered discoloured if the discolouration on the seed coat covers more than half the bean or when the discolouration penetrates the cotyledon. If the penetration of the discolouration is not obvious, cut the cotyledon crosswise in the discoloured area to determine the extent of the discolouration.
Green: Faba beans are considered green if they show distinctly green colour throughout the seed when cut to expose the cotyledons.
Heated/Rotted: Faba beans are considered heated or rotted if they are materially discoloured as a result of heating or rotting. Seed coats appear dark brown to black. The cotyledon tissue of dissected beans appears tan or brown. Heated seeds of other grains are included in the tolerance for Heated.
Mouldy: Faba beans are considered mouldy if they show clear evidence of mildew or mould.
Perforated: Faba beans are considered perforated if they show clear evidence of hull perforations caused by insects or disease.
Rime: White rime is the adhered lining of the seed pod.
Faba beans that are completely and densely covered with white rime are considered damaged.
When the rime is sparse enough to expose the soundness of the bean, the bean is sound and the rime is considered in the general appearance of the sample.
Splits: Include halves or smaller pieces of faba beans; halves that are loosely held together by cracked seed coats; and faba beans with cracked cotyledons, such as from artificial drying. Splits do not include faba beans that are otherwise damaged.
Sprouted: Faba beans in which the hull is parted over the area of the germ as a result of sprouting are considered damaged
Odour: There is no numeric tolerance for odour. Consider the basic quality of the sample, the type and degree of the odour, and the presence of visible residue causing the odour.
An excessive objectionable odour not associated with the quality of the grain, but not heated or fireburnt, is graded as “Faba beans, Sample Canada Western (CW) /Canada Eastern (CE) Account Odour”.
Heated: Faba beans than have an excessive heated odour, are graded to “Faba beans, Sample CW/CE Account Heated”.
Fireburnt: Faba beans that have an excessive fireburnt odour, are graded to “Faba beans, Sample CW/CE Account Fireburnt”.
Foreign material: Includes any material other than whole or split faba beans. These can include Ergot and Sclerotinia, insect parts, stones and earth pellets, and any other material not removed by normal cleaning.
Hard earth pellets are pellets or stones that do not crumble under light pressure.
Soft earth pellets are pellets that crumble under light pressure. These can include earth and fertilizer pellets, or any non-toxic material of similar consistency. Earth pellets may be removed as dockage.
Stones are hard shale, coal, hard earth pellets, and other non-toxic materials of similar consistency. Stones are handpicked from a representative portion of the cleaned sample, and the stone concentration is determined in the net sample.
Fertilizer pellets are manufactured plant nutrient product used by producers in the production of grain. They are typically small, round or irregular shaped and usually white, grey, brown, pink or reddish in colour.
Fertilizer pellets are assessed as stones when constituting 1.0% or less of the net sample weight. Greater than 1.0% are assessed as contaminated.
Ergot is a plant disease producing elongated fungus bodies that have a purplish-black exterior, a purplish-white to off-white interior, and a relatively smooth surface texture.
Excreta is excrement from any animal including mammals, birds, and insects.
Insect parts refer to pieces of insects such as grasshoppers and lady bugs that remain in the sample after cleaning or processing.
Samples are analysed for the percentage of insect fragments and graded according to established tolerances.
Insects may also result in seed staining and earth adhering to the seed and may result in samples having an objectionable odour (see odour grading).
Samples containing staining will be considered to be earth tagged and grading according to colour definitions.
Sclerotinia sclerotiorum is a fungus producing hard masses of fungal tissue, called sclerotia. The sclerotia vary in size and shape, have a course surface texture, vary in exterior colour from dark black to grey to white and have a pure white interior.
Treated seed is grain that has been coated with an agricultural chemical for agronomic purposes.
These seed dressings contain a dye to render the treated seed visually conspicuous.
The colour of the dye varies depending upon the type of treatment and the type of grain.
The current Canadian colour standards for pesticide seed treatments cereals are pink or red.
Seed treated with an inoculant may have a green stain.
The coatings or stains may appear greasy or powdery and surface area distribution ranges from tiny flecks to complete coverage.
Contaminated is defined in the Canada Grain Act as: “Contaminated means, in respect of grain, containing any substance in sufficient quantity that the grain is unfit for consumption by persons or animals or is adulterated within the meaning of the regulations made pursuant to sections B.01.046(1), B.15.001 and B.15.002(1) of the Food and Drugs Act.”
Samples deemed to be contaminated by the Grain Research Laboratory in consultation with the Chief Grain Inspector for Canada are graded “Faba beans, Sample Condemned”.
If a sample is suspected of being coated with a pesticide, desiccant, inoculant or if the sample contains evidence of any foreign chemical substance other than fertilizer pellets, the sample shall be graded “Faba beans, Held IP Suspect Contaminated Grain”.
Samples containing fertilizer pellets > 1.0% are graded “Faba beans, Held IP Suspect Contaminated Grain”.
Earth-tagged seed has dirt attached that cannot be removed.
To reduce earth tag in chickpea, follow these management tips:
Select a variety with a good harvest rating.
Roll your faba bean before crop emergence to eliminate ridges and an uneven seed bed, as this approach will minimize dirt entering the combine (normal plant dust will not adhere to a chickpea coat, but combined soil will).
Use glyphosate for pre-harvest weed control when seed grain moisture is less than 30%.
Use a desiccant at 30% grain moisture content to even out crop drydown and eliminate green weed material. Green material is either green weeds or green chickpea plant material that will increase the level of earth tag on the seed.
Prior to applying either glyphosate or desiccant, check with potential buyers and Keep it Clean to mitigate risk.
Combine when seed moisture content reaches 18% – 20%.