DRY BEAN SEEDING RECOMMENDATIONS

SEED

• Use seed with both high germination and vigour.
• Dry bean is very sensitive to a number of seed-borne diseases – it is critical to plant disease-free seed.
• Purchasing seed from areas isolated from commercial production will ensure seed is disease-free.
• Ensure seed lots contain sound, whole seed and that seeds have few hairline cracks.
• Bean seed is very fragile – take care to ensure the seed coat is not cracked during handling or seeding, as bean seed with cracked seed coats will not germinate, resulting in a decreased plant population.
• Managing the moisture of the seed can also reduce mechanical damage. Seed with a moisture content of at least 14% is less prone to cracking.

SEEDING DATES

• Bean plants are not frost tolerant, so seeding should not begin until the likelihood of frost has passed (in southern Alberta, this normally results in a seeding date between May 20 and May 25).
• Having epigeal germination means the growing point and cotyledons are both above-ground, making them particularly vulnerable to late spring frosts. Seeding much later than June 5 puts dry beans at risk of early fall frosts.
• The crop must be completely mature before the first fall frost, or crop quality will suffer.
• Ideal soil temperature for germination of dry bean is 15˚ C – seeding when soil temperatures are below 12˚ C will result in slower emergence and weaker plants.
• Cool, moist soil provides an ideal environment for insects and disease, resulting in damage to young seedlings.

SEEDING DEPTH/SPACING

• Bean seed should be placed into warm, moist soil to a depth of 1 to 2.5 inches (2.5 to 6 cm).
• Seeds planted too shallow risk drying out as the relatively large bean seed requires quite a bit of moisture to hydrate. If planted too deep, plants struggle to emerge and are more prone to seedling diseases.
• Bean plants crowded in rows can help break through heavier soils if pushing at the same time. Even germination makes the timing of all operations easier throughout the growing season and harvest.
• Dry bean is generally grown as a row crop – space rows so that cultivation and harvesting equipment can be used efficiently (row spacings vary from 22 to 30 inches (56-76 cm), with 24 inches (61 cm) being most common).
• Dry beans can be successfully grown when planted with air drills and seeders on narrower row spacing (6 to 12 in), and are referred to as solid seeded when grown this way. Given the large difference between row spacing in these two systems, different management practices are followed.
• Narrow row crops should produce higher yields, but high disease pressure (particularly white mould) and higher harvest losses result in lower yields compared to wide row crops.
• Solid seeded bean requires much higher seeding rates, and care is needed to obtain a uniform seeding depth and to minimize seed damage.

SEEDING RATE CALCULATOR

• The Government of Alberta’s Seeding Rate Calculator can help you determine the proper dry bean seeding rate.  

SEEDING RATES

• 25 – 45 plants per square metre
• Seeding rate should be targeted between 95-100,000 plants per acre.
• The number of seeds per pound will vary between varieties and types (as well as from year to year), so do a seed count with all lots.

SEEDING RATES FOR PLANTING ROW CROP DRY BEANS 

• Specialized row crop equipment is used to plant beans in rows 70 to 90 cm (30 to 36 in) apart.
• Given the precise placement and metering of row crop seeders, dry bean seeding rates are targeted to obtain a precise number of viable seeds per acre.
• While ideal plant stand densities will vary somewhat based on bean type, most target 100,000 plants per acre, or 18 seeds per metre of row. This works out to around 40 to 50 pounds per acre (lb/ac) of seed, depending on the size of the seed.

SEEDING RATES FOR SOLID SEEDING 

• When beans are seeded using air seeders and air drills on narrower row spacing, several adjustments are made to the row cropping system:
  • Populations are adjusted to take advantage of the more even distribution of plants across the ground.
  • Determinate bush-type varieties are chosen that resist lodging better and have higher pod set for harvest.
  • Extra care to reduce seed damage when being handled and put through the seeders and drills.
  • Tramlines should be considered to avoid damage when spraying that can result in delayed beans, complicating harvest timing.
• When grown on narrower rows, bean plants are not as crowded and are more evenly distributed across the field. This means seeding rates can be adjusted to take advantage of the reduced in-row competition.
• Seeding rates tend to be heavier and will increase seeding costs in solid seeding systems, compared to row crop seeding.
• Growth habit will also affect seeding rates. Indeterminate vine-type beans will require lower seeding rates than determinate bush-type, as the plants vine more and will cover the ground more quickly. Some air through the canopy is important to reduce diseases, so too heavy of a seeding rate is discouraged.
• Seeding rates should be calculated for the specific seed lot, based on the seed size. Generally targeting 45 plants per metre squared (four plants per square foot) on solid seeding dry beans is a good target.
• A major concern and consideration when solid seeding beans is maintaining seed quality.
• Beans are very susceptible to mechanical damage and damaged beans can develop a condition termed baldhead, where only the cotyledons and stem emerge but no leaf development follows.

SEEDS PER POUND

• 1,300 – 2,300 seeds per pound.
• Thousand Kernel Weight (TKW) varies within market classes and between market classes, in general ranging from 200 – 350 grams/1000 seeds.

SOIL TEMPERATURE

• Recommended soil temperature of 18˚C.
• Seeding within this time also generally means soil temperatures are warmer. Ideally, soil temperatures should be at a minimum of 12°C for quick germination and growth.
• At cooler temperatures these processes will be much slower, increasing the risk of seedling diseases, and delaying the time to emergence.
• If soil moisture is too low to initiate germination of this large-seeded crop, an irrigation prior to seeding followed by a light tillage operation is strongly recommended
• Irrigating after seeding often reduces soil temperature below that required for bean germination – this low temperature may increase both the incidence of fungal diseases of the root system and the chance of damage to the seed (and germinating seedling) by insects.

Other Considerations

TYPE OF EQUIPMENT

• Vacuum or air precision planters provide the most uniform seed drop per foot of row and minimize the amount of seed required, thus reducing the cost of seed per acre and minimizing inter-plant competition.
• If using an air drill to seed beans: To reduce damage operate at as low of fan and air speed as possible, while still ensuring even distribution across the air drill. It can be difficult to get even distribution, as often there are gaps in the row followed by heavy density if distribution is not even.
• Some drills can be modified with seed deflection pads in manifolds to reduce cracking. Using conveyors when possible, rather than augers, will also help.

LAND ROLLING 

• If sown in wide rows with traditional planters, rolling is not necessary.
• If using an air drill (solid seeding) rolling may improve germination and promote even emergence.
• Rolling should only be done before crop emergence.
• Refer to Government of Alberta Land Rolling Guidelines for Pulse Crops in Western Canada
• Tips for Rolling your Pulse and Soybean Crops

GROWTH STAGES

• To understand the growth stages of the dry bean – refer to Dry Bean Growth Staging Guide.