Harvesting Pulse Crops

Pulse crops can be swathed and threshed or straight combined. However, the choice depends on machinery availability, the crop type, shattering resistance, stage of maturity and uniformity of maturity. Below are guidelines for the different types of pulse crops:

Chickpeas: Chickpeas do not cure well in the swath, resulting in high green seed if swathed or desiccated too early. Best yields are obtained when crop is left standing and then straight combined. Swathing may result in lower yield, higher green seed and seed infection from both fungal and bacterial diseases, resulting in reduced quality and yield.  Desiccation is a better alternative to swathing. However, you have to wait until at least 80 per cent of the pods have turned brown. A killing frost in late fall could actually facilitate quicker combining. The sooner the crop matures, the better the yield and quality.  Immature areas in the field should be combined and stored separately.

Dry beans: Due to non-uniform maturation in the field and susceptibility to shattering, beans are better swathed than straight-cut. Straight-cutting requires even maturity and high pod clearance.  Immature beans can dry down in the swath without losing quality or shattering.

Lentils: Lentils can be swathed or straight cut depending on grower preference. However, due to the indeterminate growth habit of some lentil types, significant losses can occur if left to mature and dry in the field. Hence, the crop is often swathed or desiccated to achieve uniform dryness and good colour.

Field peas: Peas can be swathed prior to full maturity or straight combined at full maturity. However, to preserve green colour, green peas are usually swathed or desiccated early and combined as soon as possible before bleaching occurs. If straight cutting is planned, desiccation prior to maturity may be necessary. Yellow peas and feed peas can be swathed prior to maturity or straight cut when mature.

Fababean: Due to the high risk of shattering, fababean is best swathed and combined when dry than allowed to mature and straight cut. There are no registered desiccants.

How do I know when my pulse crop is ready for harvesting?

Close monitoring is the best method. The producer must walk the fields and examine the crops closely. Determining when to harvest depends on whether the producer plans to swath, desiccate or straight-cut. Does it matter whether I desiccate with Reglone or glyphosate?

Reglone is a herbicide that kills plant tissues immediately on contact, and therefore speeds up the drying process for both crop and green weeds. Conversely, glyphosate is a herbicide that kills the plant slowly after absorption and translocation to the growing points in the plant. Glyphosate is used in a pre-harvest application to control perennial weeds such as quackgrass, perennial sow-thistle, toadflax, dandelions and Canada thistle. Therefore, glyphosate is generally not referred to as a desiccant because it contributes only slightly to the dry-down of the crop. Depending on the weather conditions, crop dry-down after a pre-harvest glyphosate application can take anywhere from one to three weeks or more under extremely cool and cloudy conditions. To achieve rapid dry-down for the purposes of managing harvest, Reglone is a better choice. Liberty is also registered for desiccation of lentils. The speed of dry-down with Liberty is somewhere between Reglone and glyphosate. The choice and timing of each product depend on the crop in question. Glyphosate is registered for pre-harvest perennial weed control in dry beans, field peas, lentils, chickpeas, faba bean and lupin (not all products are registered for all crops, please check labels before applying). Reglone is registered for desiccation in chickpeas, dry beans, field peas and lentils. Note that pre-harvest treatments do not accelerate the maturity of the crop. They will kill and dry-down the crop at any growth stage. Hence, it is up to the producer to ensure that the crop has reached acceptable level of maturity before applying a desiccant.

Can I apply pre-harvest glyphosate to pulse crops to be used as seed?

No, you should not apply glyphosate to pulse crops intended for use as seed. As the glyphosate may be translocated to the filling seed, the residual glyphosate in the seed will lead to poor germination and seedling damage when the affected seeds are planted.

Is there any preferred time of day for swathing?

Swathing at night or early in the morning when there is dew on the crop will minimize the risk of shattering. Swathing under conditions of high humidity can also reduce the risk of shattering.

Do I need to roll the swath?

Rolling helps anchor the swath into the stubble or flatten it and reduce the risk of swath blowing in the wind, especially in low-cut crops like peas and lentils. However, rolling may also cause shattering losses, especially if conditions are dry.

Are pick-up reels, vine lifters and lifter guards necessary?

Pick-up reels, vine lifters and/or lifter guards have become a standard feature on pulse harvesting equipment. They improve the ability to harvest the pulses, which tend to lie low to the ground, lodge or get entangled in a mess close to the ground. If the crop is swathed, a pick-up reel will help move the plant material off the cutter bar. Lifter guards on the swather allow closer cutting to the soil surface. The pick-up reels and vine lifters should be adjusted properly to provide maximum lifting action. The reel speed should coincide with ground speed.