March 28, 2017
Vicki Brooks Blog: Managing our wheats with the right early support
After picking-up nicely in a couple of warm weeks, crop growth ground to a halt as temperatures fell back once again. Continuous wind and regular rain haven’t helped our fieldwork either.
So, as I write in the first half of March, we’re well behind where we hoped we might be a month ago. Some fertiliser has gone on. Some spring barley and beans have gone in. And a crop of rape we held back from treating before Christmas given serious doubts over its viability has had an early light leaf spot dressing. Apart from this, though, we’re waiting on the weather.
Our earlier drilled wheats have, however, been tillering well with some nice healthy new growth. Unfortunately, there hasn’t been enough sustained cold to get rid of many old leaves which are carrying more than enough Septoria for comfort. This is a particular concern with the frequent rain events we’ve been having.
While our later-drilled crops have only really begun to tiller in the past few weeks, they’re much cleaner and at noticeably less early disease risk; a valuable extra benefit of delayed drilling for black-grass management.
We’ve yet to see yellow rust anywhere yet. But with the increased susceptibility of many varieties previously known for their robustness and the lack of a good cold winter, we’re expected to find it sooner rather than later. So we’re gearing-up to keep well on top of it as well as Septoria.
In doing this we’re employing valuable new guidance from Dr Rosemary Bayles and Bill Angus to minimise our risk. While a variety like Costello continues to have an 8.9 resistance rating in Agrii trials, for instance, because it shares a good part of its ancestry with KWS Lili which now has a rating of 5.8 we’ll be keeping an especially close eye on it where the two are being grown anywhere near each other. The same goes for Revelation alongside JB Diego.
Our disease management programme starts in earnest with T0 in the next couple of weeks. In addition to Septoria and yellow rust we’ll be targeting eyespot here. Too many people seem to be too focused on foliar diseases at this stage. Yet eyespot is becoming noticeably more of a problem and we know how much grief it can cause if we don’t nip it in the bud early enough.
Our earlier drilled wheats will have solid programme based around metrafenone, epoxiconazole and fenpropimorph with a multi-site protectant.
We’ll be using a less powerful combination of prochloraz, proquinazid and tebuconazole plus multi-site for the later-drilled crops. Despite their lower disease risk, more open canopies mean they’ll rely more on the lower leaves for their yield. So it’s important we keep these as clean as we can from the start. Otherwise we’ll just end up having to spend more later on.
All but our most forward crops will be getting a low temperature active PGR with their first fungicide to promote rooting and tillering, to maintain the most robust canopies, and as extra insurance for the future with the weather as unpredictable as it continues to be. With tissue analysis confirming the need, most will also be getting a good dose of foliar manganese and zinc.
There’s really not much to say about our winter rape this month, other than the fact that it’s holding-up reasonably well against both pigeons and flea beetle larvae, has got plenty of growing to do and is now most unlikely to need any spring PGR.