March 5, 2021
Cropwatch South – February 2021
Another season of fancy drilling footwork sees us with three distinct types of wheat – all looking promising but each requiring a different approach to fulfil that promise.
The crops drilled on our low black-grass ground in late September are thick and carrying too many tillers for our 700 ears/m2 target. To restrict tiller survival they are firmly at the back of queue for their first nitrogen. And, despite generally low N-Mins after all the wet, this may be quite modest.
Some of these crops will need trinexapac as well as a low temperature active chlormequat at T0. Hopefully, the cold snap will have kept the lid on worrying early levels of rusts and Septoria. Wherever rusts remain a concern, though, our fungicide programme will be firmly based on a curative azole.
Requiring a very different approach are the wheats on our worst black-grass ground and after maize which the weather prevented us drilling until late October/early November.
These are very clean and may not need an early fungicide. However, they’re only just beginning to tiller and have suffered the most in the wet. So, we’re prioritising them for early nutritional TLC, starting with a substantial dose of nitrogen and a pre-T0 spray of Nutri-Phite PGA plus manganese with a low-temperature active chlormequat where necessary for the best root and tiller stimulation and support.
Between these extremes sit the 50% of our wheat crops drilled in a good early to mid-October window. Overall, they are very nicely structured with 2-3 strong tillers and generally low disease levels. This means it’s very much business as usual here, with nitrogen applications geared carefully to N-Mins and a low-temperature active chlormequat +/- trinexapac as part of a preventative Septoria-focused T0.
We’re very much in two minds on the multi-site front these days. It may be valuable in anti-resistance terms but folpet is hard to justify cost:benefit-wise. Thankfully, a good biological solution to our dilemma may be just around the corner. We are closely watching the ‘elicitor’ my R&D colleagues have found gives the same 0.5t/ha yield improvement as CTL at T0 by switching on Septoria defences.
Well-balanced is the best description of our OSR this season. As well as being on generally well-drained ground, it has definitely profited from not being drilled too early. Unlike some, we don’t have over-sized canopies or – touch wood – excessive levels of CSFB larvae to worry about.
Really even, strongly-rooted crops with their growing points nice and close to the ground will be getting their first N imminently. Little apparent light leaf spot gives us the leeway to hold off on stem extension spraying until nearer the green bud stage when the Toprex we’re big fans of does the best canopy structuring job.
We’re in no rush with our spring drilling either. To take full advantage of both our cover cropping and some decent frosts, what our seedbed preparation needs more than ever is time for the ground to dry out and warm-up.
Iain Richards, Agronomist – Oxfordshire