Following a high-yielding harvest – albeit with disappointing prices – thoughts now turn to new crop establishment. Early drilled crops of winter oilseed rape are progressing well (3-4 true leaves) and are through the susceptible stage for cabbage stem flea beetle (CSFB) damage. Later drilled crops are still at risk to CSFB, however, with the recent rainfall the main concern will be the current high slug pressure.
Nitrogen and phosphate was applied close to drilling to help aid plant vigour and promote taproot growth. Blackgrass has emerged in high levels in certain crops and the Centurion Max (clethodim) and early Crawler (carbetamide) applications are being carefully timed. New guidance for Centurion Max allows for named water conditioners and non-EC pyrethroid insecticides to be added. In hard water situations, this is important to prevent the lock up with calcium and magnesium ions.
Aphids will require monitoring over the next few weeks for turnip yellow virus (TuYV) control. Myzus Persicae numbers (TuYV vectors) are currently low, however, peak migration can continue into early October.
Winter wheat drilling has begun where blackgrass control is less of a concern. Recent wet weather has helped germinate blackgrass on cultivated land to allow for applications of glyphosate. The debate regarding how long to delay drilling is dictated by soil conditions. This particularly applies to heavy land growers. All benefits of delayed drilling will be lost if the crop is poorly established and the soils become too wet to apply the residual herbicide. It’s important to use high seed rates to increase crop competition. Drilling during late September/early October, aim for 250-300 seeds/sq m, dependent upon the tillering capacity of the variety.
With the decline in performance from post-emergence graminicides, this has put more emphasis onto autumn residual programmes. In difficult areas this will consist of stacking actives either all at pre-emergence, or if conditions allow a pre-emergence followed by an early post-emergence split, to help persistence. This also allows the essential residual building block, flufenacet, to be applied up to a total of 360g/ha. A new product this year, System 50 (flufenacet) has allowed flexibility with mixing. Avadex (tri-allate) has proven a useful addition and will be the starting point of some programmes.
The last two years have produced big harvests and as a result, it will be important to manage phosphate and potash off-take. Fresh fertiliser P in the autumn can be very useful to help establishment, with fresh K applications in early spring to help meet the big spring demand.
Cover crops have established well and shown this year that there is no substitute to early drilling behind the combine while moisture is present.