South: Rough September-sown seed-beds favour slugs
As we move into the final week of October we’re all drilled-up, with our best drillings by far in the second week of the month.
The much cooler autumn and cultivations delayed by the late harvest in many cases meant some decidedly rough seed-beds on any heavier ground sown before the end of September. This has played into the hands of hefty slug populations and left a big question mark over pre-emergence herbicide efficacy.
At the same time, as my R&D colleagues find every year at their Stow Longa blackgrass technology centre, a really strong early October flush of grass weed growth has compounded the challenge here.
In complete contrast, holding our drilling nerve has made the very most of the conditions. We’ve been able to get rid of a large amount of blackgrass before planting and sow into just the sort of seed-beds we want for the best pre-emergence herbicide activity and residuality, together with the most rapid slug-defying establishment.
This sort of patience is certainly not for the faint-hearted. However, with one possible exception, I can’t recall a season where we haven’t had a decent week’s drilling window between early October and early November, even on heavy land. So it’s all a matter of having everything prepared and sufficient capacity and determination to get the job done as soon as the conditions are right.
Conscious that we need to be careful what we wish for, our later-drilled wheats could really do with just what the immediate forecast promises – a good drop of rain. This will even-up emergence, boost pre-em activity and set the crop up well for the peri-emergence applications we plan on the worst blackgrass ground; all of which should be on by the time you read this.
Our oilseed rape could do with a little more moisture too plus some milder nights to really help it put on extra growth ahead of the winter. We’ve a lot of high oleic, low linoleic (HOLL) varieties in the ground this year and, aided by two phosphite applications in some cases, it’s coping well with the conditions – although without the dramatic speed of development we’re used to with “double low” hybrids like DK Excellium.
Most of the crops are good and even, with earlier drillings at six true leaves and the majority at two to four, and putting the intense slug threat behind them. Thankfully, we haven’t had to apply more than one insecticide to keep flea beetle at bay and all our early herbicides went on well – including the clethodim we’ve used to hold blackgrass at bay wherever necessary. That way we won’t be tempted to go in too early with the propyzamide.
Despite all the warnings, we’ve yet to see phoma at anywhere near threshold levels so far. Strong resistance in the varieties we’re growing looks like standing us in good stead again, allowing us to concentrate our autumn fungicide on a single November application targeted at light leaf spot as much as phoma.