2017 has been a much better year for yields of Oilseed Rape (OSR), with many crops achieving an excellent yield of 1.8 to 2.2 tonnes per acre. With future contract prices running at €380 per tonne at 9% moisture for next harvest, this will leave oilseed rape a popular crop choice for planting this autumn.
When and How to Sow Oilseed Rape:
The ideal sowing date is from mid-August to early September (preferably before September 5th), however, seedbed quality is as important as the sowing date.
When it comes to crop establishment, direct drilling using a subsoiler can work well, but the seedbed must be fine and firm. Check that there is enough fine tilt behind each leg to allow germination and establishment. Avoid pre-emergence herbicides when seed is not covered by clay. This is the disadvantage in this system, and careful weed management is needed in the weeks following emergence.
The Department of Agriculture Recommended WOSR List is the best source of information on the main varieties. Growers should consider attributes other than yield, such as standing ability, light leaf spot resistance, etc., before making their decision. Popular varieties will be DK Extravert, Dariot, SY Harnas and Alizze to mention few.
Sow 60-80 seeds/m2 to establish 30-50 plants/m2 in the spring – seed rate will depend on whether hybrid or conventional varieties are being sown. Varietal differences in vigour, thousand-grain weight, seedbed conditions and sowing date must be accounted for. Poor seedbed and late sowing will need higher seeding rates; roughly 10%.
Slug numbers are always high so it is important to remain vigilant. Where seedbeds are dry, activity should be reduced, but don’t expect numbers to be low after a couple of dry months. It is important to bait for slugs and treat accordingly. Experience has shown that direct drilling will potentially present more slug problems than other systems.
Field history is important, as pre-emergence weed control is the most effective. Volunteer cereals, cleavers and grass weeds are the main competitive weeds and do the most damage early in the crop’s growth. Apply pre-emergence or early post- emergence treatments.
For more information or assistance on sowing a managing a crop of oilseed rape, contact the RED MILLS agronomy team.
- Winter oilseed rape