West: Weather causing patchy start to spring fieldwork

As agronomists we must spend more time than most professions watching and worrying about the weather forecast, whenever I start to turn my thoughts to writing these articles I say to myself I can’t go on about the weather again, but it governs so much of our decision making that it has to be mentioned. Plus I am usually penning my words on a Sunday night and the weather for the week ahead is part of the process and opportunities for field work are at the forefront of my mind.

Soils just start to become travelable after a few drying days and then we get an Atlantic low that deposits an inch of rain and puts field work on hold again as we did 10 days ago. The forecast for the coming week looks like a repeat performance, but at least this week’s dry weather has allowed some spring crops to be drilled in the last couple of days and the first applications of N+S fertiliser to be applied.

We have also taken the opportunity to apply herbicides for ryegrass, wild oat and brome control where weeds and crops were actively growing. Although we have had some cold nights, I concur with some of my fellow Crop Watchers that it is better to get herbicides on to smaller grassweeds than wait for the ideal soil and air temperatures. However, I am fortunate that we don’t have too much blackgrass (yet) and what we do have is generally “girly” non-resistant and responds well to contact herbicides, therefore maximising every last degree of control is not as necessary.

Winter barley has had its first split of plant growth regulator (PGR) and I have generally included a low rate of fungicide, spending around £8-10/ha to quell the mildew, brown rust and rhynchosporium. After last year’s good performance when I used T0 fungicide and the science telling us that tiller number and grain sites are important, I am convinced that a clean start in barley gives a yield advantage. The best way to reduce cost of production is to maximise yields.

It has been tempting to start on T0 fungicides in wheat in the last week, but even my most forward crops that have first node at 1cm (GS30) I still predict won’t have eventual leaf 3 fully emerged until mid- April at the earliest, especially with cooler temperatures forecast this week, so T0’s on these will hopefully be going on by the time this goes to print.

The importance of timing fungicides by leaf layer emergence is critical. It test’s the patience and dexterity of agronomists (oh how I wish at this time of the year I could break my finger nail biting habit), but it is the only way to target the correct leaf layer, as leaves can emerge from different nodes depending on variety and drilling date.

Oilseed rape has rapidly moved into stem extension and most crops look to have very good potential. Light leaf spot has not developed significantly, but I have found slightly higher levels in crops that had a more PGR-focussed treatment in the autumn, so these have been treated since my last article. But with the crop value where it is I have, where possible, delayed the next fungicide until a yellow bud timing. I hope this will cover both light leaf spot and early sclerotinia protection. Similar prudence has been applied to controlling any remaining broadleaved weeds in strong and smothering crops. This may result in some weedier crops than we have been used to at dessication timing, but we have to try to reduce growing cost in this crop.

So it has been an intermittent start to spring field work, but hopefully the weather will allow us and our growers enough opportunities to get our programmes timed correctly, then our nail biting anticipation of every weather forecast will be vilified. Did I mention the weather?!

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