Oilseed rape futures prices recently reached record highs, with forward prices for Nov 2012 going over €430 per tonne.
Based on these prices, a 3.5t/ha (1.4t/ac) crop of oilseed rape will leave more profit margin than a 10t/ha (4t/ac) crop of winter wheat.
There is an oilseed rape break crop benefit for a following first wheat crop.
Other combinable break crops such as beans and oats also need to be assessed for profitability in your situation. And the soil structure benefits and ability to control difficult grass weeds in winter oilseed rape (WOSR) are two other considerations.
The recommended sowing date is mid-August to early September (ideally before Sept 10).
Seedbed quality (fine and firm) is as important as the sowing date.
Establishment by direct drilling using a sub-soiler has become very popular, and worked well last year.
Check that there is enough fine tilth behind each leg to allow germination and establishment. Don’t expect the sub-soiler (even at depth) to eliminate compaction in wet soils. Avoid pre-emergence herbicides if the seed is not covered by clay.
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 choosing a variety.
Sow 60 to 80 seeds/m2 to establish 30 to 50 plants/m2 in the spring. Varietal differences in vigour, thousand-grain weight, seed bed conditions and sowing date must be accounted for.
Higher (10%) seeding rates are needed if the seed bed quality is poor, and sowing is late.
Watch out for slug damage this autumn. Bait for slugs and treat accordingly. Direct drilling (using a subsoiler) has a higher risk of slug problems than other establishment methods.
Field history is important, pre-emergent weed control is the most effective. Volunteer cereals, cleavers and grass-weeds are the main competitive weeds, and do their damage early in the crop’s growth.
Apply pre-emergence or early post-emergence treatments.
© Irish Examiner Ltd. All rights reserved