November 1, 2017
Iain Richards Blog: The joys of delayed wheat drilling
The driest spell since before harvest has really improved ground conditions over the past couple of weeks. As a result most of our later-drilled wheats have gone into better seedbeds than many end-of-September plantings on lower black-grass risk ground.
Once again, our patience in holding-off on drilling has been rewarded. Most importantly, it has enabled us to spray-off two huge pre-planting flushes of black-grass, much of which has taken a long time to come through despite more than enough moisture; a consequence of ‘high dormancy’ perhaps?
Interestingly, we saw substantial early black-grass germination too. Judging by the amount of growth already present when we desiccated our rape and beans, though, this came from high levels of early shedding. It’s sobering to see how much black-grass can escape notice under tall crop canopies.
This season has really underlined that late drilling alone is not enough. For the most effective black-grass management it has to be combined with the earliest post-harvest cultivation. Wherever this proved impossible we’ve only managed to eliminate a single weed flush ahead of wheat drilling, leaving plenty more seed down there.
Ground moved immediately behind the combine has also taken the regular rainfall we had throughout September much better than any cultivated later. And it has weathered down well for rapid drilling with minimal soil movement; just what we need both to cover the acres and to avoid waking-up more black-grass.
Good late-October seedbeds have meant excellent seed-to-soil contact and consolidation. As well as getting the wheat away as rapidly as possible, this should make slugs far more controllable.
Although late-drilling into good conditions should also reduce the BYDV threat, we’ve still had the vast majority of our seed Deter-dressed. Very limited opportunities to spray on heavy land going into December makes this insurance vital. We’re very glad we’ve got it too, as Rothamsted monitoring shows relatively high numbers of migrating aphids and there’s another mild early winter in prospect.
With our management attention so focused on wheat drilling, it’s good the winter rape is growing away so strongly. Until recently it was looking decidedly purple with very wet feet. But the dry weather has allowed it to pick-up impressively.
Only a handful of our crops had flea beetle problems and these have been far more to do with seedbed condition than sowing date. Where we’ve had fine, firm seedbeds our insistence on vigorous varieties and seedbed fertiliser has enabled the rape to grow away from attack and given the beetles no place to hide from pyrethroids. But where seedbeds have been cloddy it’s been a real struggle.
Solid phoma resistance has certainly come into its own this year. It’s a long time since we’ve seen so much early pressure from the disease. While we’ve had to support some crops with an early curative spray, we haven’t seen a single lesion in varieties with the strongest resistance. So it looks like we’ll only need a single November spray with these again.