We are approaching the end of the season for this year’s rapeseed crop. Here are some tips from Luke Spainhour of TechCrops International on properly timing your harvest. When the plants begin to turn tan, it is time to start checking maturity.
The color of the seeds within the pods are used as an indicator of maturity. The seeds will turn from green to tan to brown to black as they mature. To gauge the maturity, take a primary stem and visually divide it into thirds. Top, middle, and bottom.
Take a couple pods from the top and bottom sections and split them open to see the color of the seeds. When the seeds in the bottom section are black, and the seeds in the top section are any color but green, it’s time to harvest. Here are some photos below that show the progression of seed color.
In fields with wide rows, desiccation is sometimes necessary to reduce yield losses to shattering. Diquat, not paraquat, should be used for desiccation. To decide when to desiccate, split some pods on the primary stem to look at the seed color. When 70% of the seeds on the primary stem are brown or black, its time to desiccate. The field should then be harvested within the next 2 or 3 days.
Several spots in the field should be checked when using either of these methods to account for inconsistencies within the field. At the end of the day we are shooting for around 9% moisture in the seeds. Around 3% moisture can be lost per day in warm, dry conditions.