March 3, 2017
Vicki Brooks Blog: Coming through the winter with considerable promise
With the possible exception of beans suffering more foot-rotting than we’d like, most of our autumn-sown crops seem to be thriving from the continued week-on, week-off winter. As we move into mid-February, the cereals and what remains of our rape are looking green, healthy and full of promise, without that yellow and hungry look they so often have about now.
Yet, neither they nor any surviving grass weeds are growing away, threatening to get ahead of both themselves and us. And, in most cases, the decent amount of cold has also held aphids and diseases nicely at bay.
If all goes according to plan, by the time you read this things should have warmed-up enough for us to have completed a good spring weed tidy-up, got on with our first fertiliser splits and be well into winter rape stem extension spraying, not to mention making a start on spring planting.
Varying quite widely, our early N-Mins are generally up on the past couple of years, reflecting the particularly dry, leaching-free early season. This and big variations in crop development between relatively wetter and drier parts of fields is making fertiliser planning interesting. Variable rate applications are, indeed, even being considered by those who’d never previously entertained them.
As usual, we’ll be prioritising our winter rape and later-drilled and second wheats for early nutritional attention. Depending on their growth, they’ll be getting 60-80kg/ha of N, well-balanced with sulphur. Practicalities mean most of the SO3 will be going on early where we’re using solids while with liquids the sulphur will be more drip-fed through the season.
Following the latest research showing valuable winter crop responses even where soil indices are satisfactory, we’ll be applying around 50kg/ha of fresh phosphate in many cases this spring too; using the specialist P-Reserve coating AgriiFocus trials have shown to be valuable in minimising mineral lock-up, wherever necessary.
More tissue analyses are also on our agenda this spring. In previous years they’ve highlighted low manganese and zinc levels in our wheats and boron and molybdenum imbalances in the rapes. But rather than just applying these micro-nutrients as standard or using belt-and braces broad-spectrum products, we’re keen to give our crops the quality trace elements they actually need in the right balance. That way we allow them to fulfil their considerable potential as cost-effectively as we can.
The 50% of our rape that survived the unbelievably dry autumn followed by serious mid-winter pigeon hammering will be getting its first spring micronutrients with the stem extension spray as we move into March. To keep on top of the light leaf spot we know is lurking though can’t yet see on the leaves, this will be a combination of prothioconazole or prochloraz with tebuconazole. All but the most backward crops will also receive a specialist PGR – more to manage their variable canopies for the most even flowering than for any shortening effect.
Spring micronutrient applications for the wheat will start at T0 towards the end of March. As well as the extent to which Septoria develops in the next few weeks, our fungicide choices here will be very much variety-driven.
Where the disease risk is high, a combination of metrafenone, epoxiconazole and fenpropimorph will be our weapon of choice with a multi-site protectant included for varieties like Trinity, Gallant, and Zulu with less disease resistance than we’d like. For lower risk situations, we’ll probably go for an alternative mixture of prochloraz, proquinazid and tebuconazole with slightly less power but broader activity than a simple multi-site.