Agronomy Update - September 2020
As I’m writing this, storm Francis is hammering against the window and the trees are struggling to stand but the grass is finally starting to look green again. It’s without doubt we’ve needed this rain and with the majority of the harvest completed in the south, it will help initiate weed germination and create essential stale seedbeds as we start to implement plans for the next cropping season. The general consensus is that people are keen to see this season behind us and are optimistic and excited for the next one.
Given the autumn we experienced last year, there will be some growers wishing to sow winter cereals earlier than usual - this isn’t without risk. If this approach is taken, it needs to be matched with a realistic expectation of both post emergent herbicide efficacy and expected black-grass populations.
80% of black-grass germinates in the autumn so there is good reason, if your soil type allows it, to delay drilling. Each week that drilling is delayed results in an approximate 15% reduction in black-grass populations. In combination with stale seedbeds, this is a very economical way to manage the problem weed.
Jonny Oosthuizen - Bartholomews Agronomist
Earlier sowing also increases the chances of BYDV infection from aphids and without the Redigo-deter seed dressing, it could be necessary to spray multiple times with insecticides which doesn’t bode well for the beneficial insects.
In terms of herbicides for winter cereals, consider careful selection of the appropriate actives in relation to the target weeds. Blackgrass programs should be based around Flufenacet and Pendimethalin whilst Rye-grass programs should include Prosulfocarb.
Oilseed rape crops have the potential to progress rapidly this month and may require some help in doing so. Consider early weed control in conjunction with a bio-stimulant/root enhancing product where you’re confident in plant populations and general crop health.
The wet weather also brings slugs into the picture and with many OSR crops already well established and speeding past the cotyledon stage, it is essential that growers and agronomists measure the slug populations and utilise cultural controls before reaching for slug pellets.
Once again, a holistic integrated approach is what is required in order to get crops off to the best start possible. Close monitoring and good communication between all involved can only help in ensuring success for all this autumn.