Successful canola cultivation culminates in one critical decision: when to harvest canap. Harvesting too early results in green seeds that yield lower oil content and are prone to cracking during threshing. Waiting too long, however, risks pod shatter, where mature pods burst open and scatter seeds across the ground, leading to significant dockage and loss. Mastering the precise window for combining requires understanding the crop's development stages and monitoring specific field conditions daily.
Understanding the Growth Stages
To determine the optimal time, growers must first identify the current growth stage of the crop. The journey begins with germination and progresses through vegetative stages, bolting, and flowering. Flowering is the most visible phase, where bright yellow blossoms cover the plant. Following pollination, the pods begin to form and subsequently mature. Recognizing the transition from flowering to the later stages is essential, as it dictates the timeline for when to harvest canola with confidence.
The Visual Indicators of Maturity
Assessing maturity is a visual process that involves inspecting the pods and seeds. The pods on the main stem will change color from green to a light yellow, indicating the drying process has begun. The seeds inside should transition from a creamy yellow to a distinct dark brown or black color. When you squeeze a seed between your thumbnail and finger, it should leave a firm imprint without feeling oily or leaving a residue. This color change and seed hardness are primary indicators that the plant has reached the right moisture level for harvesting.
Checking Moisture Content
While visual cues are important, the most accurate method to determine readiness is measuring moisture content. Canola must be harvested at the correct moisture level to ensure safe storage and prevent spoilage. The ideal moisture range for direct combining is between 8% and 10%. If the moisture is above 10%, the seeds may heat up in the bin and develop mold. Conversely, harvesting below 8% can increase seed loss due to shattering and reduce the overall grade of the crop due to excessive fines.
Managing the Risk of Pod Shatter
Pod shatter is a significant concern that dictates the urgency of the harvest window. Once the pods are fully dry and mature, they become brittle. Any physical disturbance from wind, rain, or the mechanical action of the combine can cause the pods to shatter open. This biological mechanism, designed to disperse seeds, results in devastating yield losses in the field. Growers often face a race against weather; if rain is forecasted and the crop is mature, harvesting immediately becomes a priority to preserve the seed, even if the moisture is slightly higher than ideal.
The Role of Weather and Timing
Weather conditions play a pivotal role in the harvest schedule. Cool temperatures and dry winds are ideal for accelerating the drying process in the field. Conversely, high humidity and frequent dew can keep moisture levels elevated, delaying the harvest. Morning harvesting is often recommended because dew can add moisture to the pods; however, if the crop is ready, a slight delay for the dew to burn off is preferable to harvesting wet grain. Monitoring the forecast allows for strategic planning to maximize uptime on the combine.
Best Practices for Combing
When the crop reaches the right stage, operational adjustments can improve efficiency. Setting the combine correctly minimizes loss and damage. A slightly higher fan speed may be required to handle the lighter, mature canola. The rotor or concave settings should be adjusted to allow the pods to pass through without excessive threshing force, which can damage the seeds. Regularly checking the clean grain and chaff walkers for seed loss during the initial stages of harvesting helps fine-tune the settings on the go.
