Irrigated Dry Bean Production

Introduction

Dry bean in Saskatchewan is becoming an important crop and is rapidly expanding in the irrigation district. Acreage in the past has been limited due to production difficulties. Following are some important tips for successful dry bean production under irrigation.

Recommendations

• Use seed from dryland production
• Moisten seed if using an air seeder or conventional seeder
• Seed at 2.5 to 6.0 cm depth
• Sow May 20-25
• Sow at 25-30 seeds/m² in rows 40-60 cm apart
• Use a fungicide
• Harvest at 16-20% seed moisture content.

Seed Inoculation

Dry bean is a pulse crop that requires inoculation with the proper strain of Rhizobium phaseoli to enable it to fix nitrogen. New studies indicate that granular based inoculum performs better than peat based products.

Seeding Rate and Row Spacing

Seed and fungicide account for about 30% of the total cash cost for dry bean production. The optimum seeding rate and row spacing to achieve the maximum yield is of economic significance to dry bean producers. Dry bean has traditionally been sown at 25-30 seeds/m² under wider row spacings (55-80 cm). Yield increases have been realized with narrow (25030 cm) row spacings. The yield increase associated with narrow row spacing is dependent upon the growth habit of the bean. Beans with upright growth habit (Type I) are better suited for narrow spacings than semi-upright (Type II) or viny (Type III) types.

Seeding Date

The seeding date of dry bean is important due to its time to maturity (110 days). The cotyledons of dry bean emerge from the soil (unlike other pulses such as pea), therefore dry bean will not regrow if damaged by frost. Dry bean should be sown May 20-25 when soil temperatures are greater than 10⁰C and when the risk of spring frost is low.

Seed Depth

Seed should be sown at 2.5-6.0 cm depth into a warm moist seed bed. Seeding too deep or too shallow can reduce germination and delay seedling development.

Seeding Equipment

Capital costs can be kept to a minimum by using conventional corn planters for seeding dry bean. With the increased use of air seeders and no-till drills, research to determine the seed handling capabilities of this equipment was addressed. Research has indicated similar stand counts and seeding uniformity using hoe drills and disc drills compared to corn planters for sowing dry beans, provided that the seed is not damaged by the seed metering rollers, and that the rate of travel does not exceed 4.0 mph. Airseeders can be used for seeding bean with the following precautions: 1) lined distribution manifolds, 2) reduced airflow, and 3) seed moisture above 14%.

Weed Control

Dry bean is a poor weed competitor. High weed populations reduce yields significantly and reduce harvest efficiency.

Irrigation Management

Dry bean is a shallow rooted crop. The majority of water used is taken up from the top 30 cm of the soil. Total water use of a dry bean crop is higher than lentil, but lower than pea or cereal crops. Irrigation scheduling varies depending upon the soil type, crop development (Table 1), and weather.

Disease Control

Sclerotinia (white mold) is a major problem in irrigated dry bean crops. Sound crop rotations, wide row spacings, and timely fungicide applications are some of the methods used to reduce the incidence of disease. The effective use of fungicides depends on applying the product directly to the bean blossoms at early bloom. A split application may prevent a second infection. A study evaluating the effectiveness of three different sprayers (skid-boom, airblast and conventional) indicated no differences in disease levels or yield among the sprayers tested. Fungicide use is inexpensive insurance against disease losses.

Harvest

Dry bean must be harvested at 16-20% moisture content in order to minimize harvest losses. The dry-down process must be monitored closely because of the rapid depletion of moisture. For example, seed moisture content dropped from 20% (slightly higher than optimum) to less than 16% (less than optimum) within two to three days when temperatures are relatively high during the fall.

Seed loss during harvesting has been the greatest drawback to dry bean production. A commercially acceptable loss for dry bean is 10%. Three main types of losses occur: cutterbar losses, combine cylinder loss and handling and storage loss. Converting direct-cut harvesting equipment for use in dry bean has received considerable attention and is being improved.

Variety Development

A breeding program to develop a non-shattering dry bean genotype for irrigated production and direct harvesting in western Canada is underway at the Crop Development Centre, University of Saskatchewan. Superior lines with the non-shattering pod (NSP) trait have been identified. Lines tested with the NSP trait have had reduced cutterbar losses by about 50% compared to lines with normal pods. Reduced shatter losses are attributable to the NSP trait, and to increased pod curvature which increases the height of the pods above the ground.