Lentil (Lens culinaris L.) is a pulse crop that is part of the Leguminosae family. Lentil plants are typically short but can range from 20 to 75 centimetres (cm) or eight to 30 inches (in) in height, depending on growing conditions.
Lentil seed undergoes hypogeal germination, meaning the cotyledons remain below-ground. The first two nodes on the stem develop at, or below the soil surface and are known as scale leaves. Scale leaves provide points for possible re-growth, should the plant sustain injury from conditions such as frost, heat canker, wind damage, or defoliation. The third node on the stem has two leaflets and is called the first true leaf. Lentil seedlings can produce a new node every four to five days under good growing conditions. Leaves are about 5 cm long with nine to 15 leaflets. Stipules, much smaller than leaflets, occur in pairs on either side of the leaf axis where it joins the stem. Just prior to flowering, new leaves will develop a short tendril at the leaf tip. At this time, usually around the 12 node stage, the first flower clusters can be seen developing at the base of the leaves.
Lentil plants have an indeterminate growth habit. Plants continue to flower until they encounter some form of stress, such as lack of moisture, high temperatures, or nutrient deficiency.
Flowers are self-pollinated. Flower stalks produce one to three flowers, which develop pods. Pods are less than 2.5 cm in length and usually contain one or two seeds. Vigorously growing lentil plants with adequate space will produce two or more primary shoots from the base of the stem. However, the main contribution to seed yield is made by secondary (aerial) branches that arise from the uppermost nodes of the main stem just below the first flowering node. Flowers that form after the first week of August may not produce filled seeds by harvest.
Lentils are a cool season crop with a relatively shallow root system (0.6 metres or 1.97 feet) and is moderately resistant to high temperature and drought. Lentils require at least moderate moisture - 15 to 25 cm during the growing season to produce a full seed set. Due to its indeterminate growth habit, lentil will often continue to flower as long as growing conditions remain favourable for vegetative growth. Therefore, low moisture or low nitrogen stress is required to encourage seed set and hasten maturity. Excess moisture before the plant is in full bloom promotes vegetative growth, thus delaying and reducing seed set and promoting fungal infections. Lentils grow best on well-drained soil with pH levels of 6.0 to 8.0. It will not tolerate flooding, or soils with high salinity.
In Saskatchewan, lentils are best adapted to the Brown and Dark Brown soil zones but can be grown successfully in the Thin Black and Black soil zones in years with moderate moisture. The development of more determinate red and small green varieties allows opportunity to expand lentil production into less traditional lentil growing areas of the province such as the moist Dark Brown and Thin Black soil zones.
Lentil varieties produce seeds ranging from size small, averaging under 40 grams per 1,000 seeds (g/1,000 seeds), to large, which average over 50g/1,000 seeds.
Seed coat colours range from clear to green, tan, brown, grey, blotched green and black, or black. Cotyledons may be yellow, red, or green, with various combinations of seed coat and cotyledon colours determining specific market classes.
Green Market Class
Varieties typically have yellow cotyledons with green seed coats and seed size is described as large, medium, and small. About 75 per cent of the green lentils are large-seeded and about 25 per cent are classified as small greens. Green lentils are consumed as whole seed. Most large green varieties require early seeding because of their relatively late maturing, indeterminate growth habit. The tall stature of these varieties can make them prone to lodging, and susceptible to Botrytis (grey mould) and Sclerotinia (white mould) infection in high moisture conditions.
Red Market Class
Varieties typically have red cotyledons with grey seed coats. Although sometimes consumed whole, red lentils are typically dehulled, or dehulled and split, to increase palatability. Red lentils are divided into large, small, and extra small market classes. Small red varieties tend to be earlier maturing and shorter than green varieties.
Specialty Market Classes
Varieties are grown throughout Saskatchewan in small volumes. Black-seeded lentil (Indianhead variety), originally intended for use as a green manure or plow down crop, has been marketed more recently as a Beluga, or black lentil. French green lentils have a green marbled seed coat with yellow cotyledons, small seed size most similar to small red lentils, and retain their shape better than small reds or greens upon cooking. Green cotyledon lentils have a green or marbled seed coat with green cotyledons and a small-to-medium seed size. Spanish brown lentils have a grey dotted seed coat with yellow cotyledons, small seed size most similar to small reds, and are sold primarily into Spain. Varieties with the Clearfield® trait (have CL suffix) have tolerance to imidazolinone herbicides, such as Odyssey®, Odyssey DLX®, and Solo®. These herbicides if applied to conventional lentils will cause injury.
Varieties differ in their height, maturity, and resistance to ascochyta and anthracnose. Ascochyta resistance rated as good is still only considered intermediate resistance and Anthracnose resistance is only to Race 1. Integrated disease management practices are important, as the varieties can still be infected with the diseases.
Long-Term Lentil Averages for Saskatchewan 2020
|Yield(% CDC Maxim)||Resistance To:|
1 & 2
3 & 4
|Small Red||CDC Maxim||CL||14||100||100||34||51||E/M||MR||MR||gray||red||40|
|Extra Small Red||CDC Imp||CL||7||95||93||35||52||E/M||MR||MR||gray||red||30|
|Large Red||CDC KR-2||CL||10||104||90||37||52||M||MR||MR||gray||red||55|
|Small Green||CDC Imvincible||CL||14||94||81||33||49||E||MR||MR||green||yellow||34|
|Extra Small Green||CDC Asterix||11||96||91||30||48||E||MR||I||green||yellow||26|
|Medium Green||CDC Imigreen||CL||11||78||71||44||50||M||MR||S||green||yellow||57|
|Large Green||CDC Greenland||19||89||70||38||52||M/L||MR||S||green||yellow||64|
|French Green||CDC Marble||12||103||96||36||49||E||MR||I||green marble||yellow||34|
|CDC Peridot||CL||8||84||94||37||48||E||I||MS||green marble||yellow||38|
|CDC Pilgrim||CL||5||96||91||35||52||E/M||--||--||green marble||yellow||33|
|Green Cotyledon||CDC Imerald||CL||5||88||82||35||53||E/M||--||--||green||green||54|
|CDC QG-2||10||89||88||40||48||E||I||I||green marble||green||32|
|CDC QG-4||CL||7||92||90||36||53||E/M||I||MR||green marble||green||33|
|Spanish Brown||CDC SB-3||CL||8||90||87||35||51||E||I||MR||gray dotted||yellow||38|
|CDC SB-4||CL||7||102||101||34||53||E/M||I||MR||gray dotted||yellow||41|
Source: Saskatchewan Variety of Grain Crops 2018, Saskatchewan Advisory Council on Grain Crops
Lentils are well suited to direct seeding cropping systems. Lentil seedlings tend to be vigorous and can emerge through crop residue and grow from greater depths versus some crops traditionally grown in Saskatchewan.
Studies conducted by Agriculture and Agri-Food Canada at Swift Current demonstrated the benefits of producing lentils on untilled stubble and the influence of the previous crop stubble height. Lentil yield increased significantly as the stubble height of the previous crop increased. While pre-worked fields produced the lowest yields. Seeding lentils into tall standing stubble helped reduce soil moisture evaporation, particularly prior to flowering, resulting in greater water use efficiency (amount of grain produced per unit of water used) by the crop. As stubble height increased, the height of the lowest pod also increased, easing harvest operations and possibly reducing shattering losses.
Fields seeded to lentils are usually rolled with a land roller following seeding or up to the fourth node stage. Rolling levels the soil, protects harvest equipment by pressing most rocks into the dirt, and reduces the risk of down-grading the harvest sample with dirt contamination (earth tag).
Lentils inoculated with the proper rhizobium (Rhizobium leguminosarum) strain has the potential to secure up to 80 per cent of its nitrogen requirement through nitrogen-fixation.
Nitrogen fixation is a symbiotic relationship, in that it benefits both the bacteria and the plant. Rhizobium enters the root hairs of the plant and induce nodule formation. The plant provides energy in the form of carbohydrates for the Rhizobium living inside the nodules. The Rhizobium, in return, converts atmospheric nitrogen into a form of nitrogen that can be used by the plant. This relationship provides maximum benefit when the supply of available soil nitrogen is low and the soil moisture and temperature levels are adequate for normal seedling development.
Rhizobium leguminosarum strains will nodulate peas, faba beans, and lentils but some strains may be more effective on certain crops or certain varieties. Manufacturers package the inoculant as either a mixed or single strain inoculant.
Once the proper inoculant is chosen, care must be taken to ensure maximum rhizobia survivability. Rhizobium bacteria (either on the seed or in the package) are susceptible to temperature stress, drying out, and damage from direct sunlight. Inoculant must be stored in a cool dark environment prior to use, and expiry dates must be observed. Inoculated seed should be planted as soon as possible.
Inoculants are sensitive to granular fertilizer therefore, banding fertilizer to the side and/or below the seed is recommended. Inoculant should never be tank blended with fertilizer. Inoculants are also sensitive to some seed-applied fungicides. Check the labels of both the inoculant and seed treatment for compatibility. When using a combination of fungicide and inoculant, apply the fungicide to the seed first, allow it to dry, and then apply the inoculant immediately prior to seeding.
Inoculants are available in different formulations: liquid, peat-based, and granular.
Liquid-based products offer convenience and better control of application rate, compared to other forms. However, the rhizobia in these formulations are more susceptible to damage from environmental extremes and direct contact with seed treatments than other inoculant forms. If treated seed is planted immediately into a moist seedbed, liquid formulations perform well.
Peat-based formulations are more durable and less prone to desiccation and damage from direct contact with seed treatments compared to liquid formulations, although care must still be taken. Some peat based powder inoculants require the use of a sticker. Adhesion to the seed can be enhanced if the seed is slightly damp during inoculation.
Granular formulations offer ease of application and should be applied in the seed row. These formulations remove the risk of incompatibility with seed treatments but care must still be taken to minimize risk of desiccation. Granular inoculants are less affected by environmental stress and seed-applied fungicides than other inoculant forms.
All inoculant formulations will perform equally well if the inoculant is properly applied and if environmental conditions are ideal. Under adverse conditions granular formations tend to perform best, followed by peat, then liquid.
Although Rhizobium bacteria can live in the soil for a number of years, efficient nitrogen-fixing bacteria may not be among those that survive. This reinforces the recommendation to inoculate each time lentils are seeded. Western Canadian research indicated a significant yield response to inoculation of grain legumes in 30 to 50 per cent of the cases. For this reason, most experienced lentil producers use an inoculant on their lentil crop every year.
Nodulation efficacy can be verified by examining the pulse crop at early flowering. It may take up to four weeks after seeding for nodulation to reach a point where it can be evaluated. The best way to check for nodulation is to dig up a plant and gently remove the soil from the roots by washing in a bucket of water. Nodules are fragile and readily pull off if the roots are pulled out of the soil.
If the rhizobia are actively fixing nitrogen, the nodules will appear visibly red or pink inside. Nitrogen fixation is synchronized with plant growth, supplying the crop nitrogen during rapid vegetative growth. Nitrogen fixation declines once plants begin pod formation and seed development.
Seed applied inoculant should result in nodules forming on the primary root near the crown. If the inoculant was soil applied (granular), nodules should be found on primary and secondary roots. Lack of nodules indicates rhizobia did not infect the pulse plant. Lack of a pink colour (usually green or cream coloured) indicates the rhizobia are not fixing nitrogen.
Soil testing is important. High soil nitrogen levels will adversely affect nodulation and fixation. As the supply of nitrogen from soil and fertilizer increases, the amount of nitrogen fixed by the plant decreases. Nitrogen is necessary for high yields, but generally nitrogen fertilizer application is not required for lentil. Lentils can derive up to 80 per cent of its nitrogen requirements through nitrogen fixation. The remaining nitrogen comes from the soil (available at time of seeding plus mineralized during growing season).
Where combined levels of soil and fertilizer nitrogen reach 28 to 40 kilograms per hectare (kg/ha) or 25 to 35 pounds per acre (lb/ac), development of nodules and nitrogen fixation may be delayed. Combined soil and fertilizer nitrogen levels greater than 55 kg/ha (50 lb/ac) can prevent effective nodulation and nitrogen fixation.
It can take three up to four weeks following planting for nodules to become fully functional. Early plant growth may be poor in soils with nitrogen levels less than 11 kg/ha (10 lb/ac), causing plants to appear yellow prior to the onset of active nitrogen fixation due to nitrogen deficiency. This early deficiency can be corrected by adding low levels (10 to 15 kg/ha) of starter nitrogen at seeding. Although high levels of starter nitrogen may appear to help the crop overcome a nitrogen deficiency during early crop growth stages, final seed yields may not increase. Typical applications levels of monoammonium phosphate (ex. 12-51-0) often provide the small amount of nitrogen needed for early plant growth and, depending on the soil test, may provide the starter nitrogen required.
Lentils have a relatively high requirement for phosphorus. Phosphorus promotes the development of extensive root systems and vigorous seedlings. Encouraging vigorous root growth is an important step in promoting good nodule development. Phosphorus also plays an important role in the nitrogen fixing process and in promoting earlier, more uniform maturity.
Lentils grown on soils testing low in available phosphorus or under cool wet conditions may respond to phosphate fertilizer. However, dramatic yield responses are not always achieved. Even if seed yield increases are not achieved every year, a lentil crop may benefit from improved stress tolerance as a result of phosphorus application.
The maximum safe rate of actual phosphate applied with the seed is 22 kg/ha (20 lb/ac) with 10 to15 per cent seedbed utilization (SBU) under good to excellent moisture conditions. Calculate SBU by dividing seed spread by row spacing. For example a 2.5 cm (1 in) spread with 25.4 cm (10 in) row spacing, equates to 1/10 or 10 per cent SBU. Rates of seed-placed phosphate should be reduced if less than ideal moisture conditions exist. Higher rates of phosphate fertilizer placed in the seed row with narrow openers like discs or knives can damage the emerging seedling and reduce the stand. If higher phosphate rates are required, band the fertilizer away from the seed (sideband or to the side and below), or increase phosphate levels in the years prior to growing lentils.
Lentils have a high demand for potassium. Use a soil test to determine whether additional potassium is needed. Seed-placing potassium may cause seedling damage. As with phosphate, a wider opener may allow for slightly higher safe seed-placed rates. The sum of seed-placed potassium (K2O) plus phosphate fertilizers must not exceed the recommended safe rate of phosphate mentioned previously (22 kg/ha or 20 lb/ac). Most of the potassium taken up remains with soil residue and is not removed with the grain. Most soils are sufficient in potassium. However, deficiencies may exist, especially in sandy Black and Grey soils found in northern Saskatchewan.
Sulphur is required in a relatively significant amount. A 30 bu/ac lentil crop requires about the same amount of sulphur as a 40 bu/ac wheat crop; approximately 9 to 11 kg/ha (8 to 10 lb/ac) as lentils remove about 0.2 lb/bu of sulphur. Soils testing low in available sulphur should have this deficiency corrected by side-banding, mid-row banding, or broadcasting ammonium sulphate, which contains sulphur in a plant-available form. Most research indicates limited yield response from the addition of sulphur fertilizer except in fields testing very low in sulphur.
Micronutrient deficiencies for lentil production have not been identified as a problem through lentil growing areas of Western Canada. If a micronutrient deficiency is suspected, it is advisable to analyze soil and plant samples within the suspect area and compare the analysis to soil and plant samples collected from a non-affected area of the same field. If the analysis confirms a micronutrient deficiency at a relatively early growth stage, a foliar application of the appropriate micronutrient fertilizer may correct the problem.
The Clearfield® Production System is one of the best ways to grow lentils. It combines high-performing red and green lentil varieties with an unrivalled portfolio of crop solutions – all tailored to your region. Here’s how you can get started:
- Decide to grow Clearfield lentils
Source seed directly from your local seed grower.
- Get your seed Clearfield-Confirm® tested
Get your farm-saved seed tested at one of the accredited Clearfield lentil seed testing labs prior to growing or selling it.
- Sign the Clearfield Commitment
The Clearfield Commitment makes it easier to grow Clearfield lentils and take advantage of all the benefits they offer including the AgSolutions® Rewards Program, without any additional costs. In 2015, BASF introduced the evergreen Clearfield Commitment for lentils. Once signed, this Commitment will extend the period of your license to use Clearfield technology without the need for an annual agreement. All we ask is for you to register your seeded lentil acres once a year.
Your Commitment helps maintain the integrity of the Clearfield trait by driving product innovation and introducing new varieties to the lentil market. When you sign a Clearfield Commitment and complete a matching Clearfield lentil herbicide purchase (Ares™, Odyssey®, Odyssey Ultra, Odyssey DLX, Solo®, Solo ADV), a portion of the herbicide sales is reinvested into the Crop Development Centre (CDC) to support ongoing research and development of new Clearfield lentil varieties.
- Benefit from BASF crop protection products
Along with high-performing red and green varieties, you can enjoy superior in-crop weed control without harming your lentils and industry-leading disease control from an innovative portfolio of products from BASF. It’s no wonder growers put their trust in the Clearfield Production System season after season, year after year.
There are different seed sizes in lentils. The large-seeded type has a seed size that averages 50 grams or more per 1,000 seeds.
The small-seeded type has a seed size that averages 40 grams or less per 1,000 seeds. Seed coat colours range from clear to green, tan, brown, gray, blotched purple or black. The cotyledons can be yellow, red or green. The different combinations of seed coat and cotyledon colours determine specific market classes preferred by consumers.
Green varieties typically have yellow cotyledons with green seed coats and are described as large, medium, and small. About 75% of green lentils are large-seeded and about 20% are classified as small greens. Green lentil is mostly sold as whole seed. Most of the large green varieties require early seeding because they are relatively late maturing and indeterminate. They produce tall plants which can be prone to lodging and are susceptible to botrytis (gray mould) infestations in high rainfall areas.
Red varieties typically have grey seed coats with red cotyledons. Red lentils are sold as whole seeds, dehulled seeds, or as dehulled split seeds, and described as large, small, and extra small market classes.
Specialty varieties are grown in much of Saskatchewan in small volumes. Indianhead is a black-seeded lentil originally intended for use as a green manure or plow-down crop, and more recently has been marketed as a Beluga Lentil. King Red is a specialty red lentil market class with a large seed size. Small quantities of varieties of the French green, Spanish brown, and green cotyledon (Queen Green) market classes are produced.
Varieties with the Clearfield trait (have CL suffix) are a recent development. This trait allows use of imidazolinone herbicides, such as Ares, Odyssey, Odyssey DLX, Odyssey Ultra, Solo and Solo ADV that would otherwise cause injury to conventional lentils.
Varieties differ in their height, maturity and resistance to Ascochyta and Anthracnose. Small red varieties tend to be earlier maturing and shorter than green varieties. Ascochyta resistance rated as ‘good’ is still only an intermediate level and Anthracnose resistance only applies to Race 1. Integrated disease management practices need to be considered as the varieties can still be infected by diseases.