Oilseed rape desiccation should have been underway this week. In the majority of situations desiccation will rely on glyphosate mixed with a pod sealant. Where crops have lodged it has mainly been due to root-lodging rather than kinking of stems.
Larger canopied hybrids and crops with high plant populations have been more affected by lodging than well-structured conventional varieties. Varietal selection for next year will include Cabernet and Quartz with hybrid choices likely to include PR46W21 and Excalibur, which have stood up better to the wet weather than most hybrids.
Any decision to grow a Clearfield variety should not be taken lightly. Accurate recording of the correct variety in each field and herbicide application will be vital to ensure costly mistakes are avoided. Subsequent management of Clearfield volunteers must consider that SU herbicides in cereal crops and sugar beet will generally not provide adequate control.
Looking at numerous wheat variety plots over the last few weeks has highlighted the importance of trying to diversify the genetics for next season. Across the NABIM groups, varieties that generally stand out as being cleaner from disease include Crusoe, Panorama, Invicta, Scout, Relay and JB Diego.
Nevertheless, late brown rust has been very active across numerous varieties, encouraging further fungicide treatment to try to maintain any remaining green leaf area. Septoria tritici is curiously distributed across fields with obvious foci of very high disease levels in places. Once trials results are all gathered in and analysed we should learn an awful lot from a very difficult season.
Strategies for grassweed management are being formulated and will ultimately depend on what sort of conditions we experience at harvest. Ploughing may well feature if it can be done well and achieve proper inversion of the soil to bury high levels of grassweed seed.
Non-inversion tillage approaches are going to have to be flexible to have any hope of achieving high levels of grassweed control pre-drilling. Delaying drilling and utilising stale seedbeds should not work to calendar dates, but instead rely on observations of grassweed emergence and make use of all opportunities to spray off with glyphosate.
Fields planned for oilseed rape can also be approached in this way – i.e. not drilling too early in mid-August but delaying towards the end of August or even very early September – but correct varietal choice will be important to ensure good establishment from later drilling. Where rape is planned for till-seeding, its worth considering moving the stubble immediately after harvest of the cereal crop to encourage a flush of grassweeds and a glyphosate treatment.