Selecting a Site

Field site selection is key when planning for field pea in the rotation.

PLAN AHEAD

• Planning for field pea production should begin a year prior to planting for good weed control and to maximize yields.

CHOOSE

• Use fall tillage or a pre-harvest glyphosate product in the crop before pea to control thistles.
• Choose fields that are thistle-free, since no herbicides are registered for complete thistle control in field pea. (see Herbicides for Use in Pea, Agdex 142/642-4)

AVOID

• Do not seed field pea on summer fallow, on heavily manured fields, or on fields that received nitrogen the previous fall. High nitrogen levels cause excessive growth, which leads to lodging, disease, and nitrogen fixation problems.
• Avoid rocky fields. Harvest operations for field pea are usually done close to the soil surface, and rocks can damage a combine.
• Avoid poorly drained fields to reduce the incidence of seed and seedling diseases.
• To reduce risk of Aphanomyces root rot, do not plant peas on fields that have had a pea crop within the last 6-8 years. Consider alternating pulse crops in your rotation between pea and faba bean/soybean/chickpea (all resistant to Aphanomyces) to maintain a four-year rotation containing a pulse crop. 
• When planning a crop rotation avoid planting peas following canola due to increased risk of infection with Sclerotinia in the pulse crop.  If you plant these two crops in sequence, plant peas and follow with canola as there are more options for control of Sclerotinia in canola.

MAINTAIN GOOD RECORDS

• Keep good records on herbicides used in previous crops – some leave residues that will injure the pea crop. Always read the herbicide label and pay close attention to re-cropping restrictions.

Seed Quality Testing and Evaluation

GERMINATION TESTING

• Germination testing is one method for evaluating seed lots for quality.
• Germination addresses the seed’s ability to develop into a normal, healthy plant under favourable field conditions.
• This testing can be misleading because seed may germinate well in the lab due to optimum conditions being present or to the fact that the seed has every opportunity to develop into a normal healthy seedling.

VIGOUR TESTING

• Vigour testing, another method, assesses the seed’s potential to withstand unfavourable field conditions by assessing certain factors that influence seed quality.
• While vigour results represent the lowest germination obtained from the lot, germination testing represents the highest result. Actual field germination would normally fall between the two.

variables impacting seed quality

• Germination and vigour are influenced by the physiological well-being and anatomical completeness of the seed plus its interaction with a wide range of environmental conditions.
• Seed vigour is affected by:
  • genetic constitution
  • seed size and weight
  • mechanical integrity and soundness
  • deterioration, aging, and stage of maturity
  • pathogens
  • climatic conditions

combined testing

• In years where unfavourable weather conditions prevail, it is best to combine a vigour test with a germination test to determine seed quality and performance more accurately.
• Be sure germination results include adequate categorization of the seedling defects and the seedling’s ability to survive adverse conditions.
• It’s impossible to predict post-seeding conditions with a vigour test, so seed is placed under a variety of stressful conditions, simulating climatic conditions as closely as possible, including:
  • cold temperatures
  • wet conditions
  • micro-organisms
  • seed soaking
  • accelerated aging.
• Under these conditions, the seed must demonstrate the ability to germinate into a vigorous seedling.

Evaluation

• Testing for vigour is an important tool if it is suspected that seed has sustained some injury or that the soil environment will impose stress on the seed.
• Field pea is very susceptible to mechanical injury, such as cracking and chipping, either at harvest or during processing, especially if the moisture level is below 14%.
• Mechanical injury, such as small seed coat cracks, results in rapid water intake that leads to dead seed cells – this dead tissue then becomes a source of food for invading pathogens
• Vigour tests must be combined with germination tests to predict field performance.
• The seed may also require 1,000 seed weight and disease tests to completely assess the seed’s total quality.

Land Rolling

PURPOSE

• Reasons for rolling a pea field:
  • to push rocks down to the soil surface
  • to break up dirt lumps and eliminate dirt problems during straight combining
  • to improve soil – seed contact and promote even germination and emergence

IDEAL TIMING

• Roll pea fields soon after seeding and when the soil surface is dry – this will also ensure the field is ready for herbicide applications at the correct node and weed growth stages (spraying should normally be done before rolling, if the crop is advanced).
• If wind or water erosion is a concern, rolling should be done just after the pea crop is up – at the two-node stage.
• Never roll pea fields in the morning – rolling wet pea leaves spreads disease.
• When stuck with late rolling and late spraying, when pea growth is advanced, spray first and roll the field three to four days later – if the herbicide has a wide window for application, roll the pea field first, as rolling causes less stress on the plant than broadleaf herbicides.

after the 5^th node

• Late rolling of pea fields (after the fifth node stage) is not recommended – this may result in bruising of the pea leaves, stem breakage and increased disease levels.

Water Ballast

• Water ballast in the roller is not generally necessary – some producers, however, add water ballast on older zero-till sites to level out the disturbed soil.

headlands

• Rolling headlands results in double rolling and is not necessary (these areas are generally much firmer) – the danger of headland rolling is that it will thin out the pea crop.

resources

• Government of Alberta Land Rolling Guidelines for Pulse Crops in Western Canada
• Tips for Rolling your Pulse and Soybean Crops