East: Considerations after a mild winter

It’s looking inevitable that we will see the typical early-spring bottleneck of spray jobs again this year.

When the recommendations begin to stack up it’s hard to prioritise – blackgrass and disease control, micronutrients…not to mention the fact that spring barley and bean crops want to be drilled and it won’t be long, depending on temperatures, before we think about getting the sugar beet in as well. Oh and you’ll probably want to be aiming to cover most crops with their first dose of nitrogen too.

So what comes first? Blackgrass control, particularly where no chemistry has been applied to date, has got to be high up the list. We start to get into the same position as last year where a late Atlantis (iodosulfuron + mesosulfuron) is worrying for a number of reasons: the temptation to tank mix, the size of blackgrass we ask our products to control and also the issue of planning for a subsequent oilseed rape crop, which could be affected by products applied this season.

Also beware the diurnal temperature range; at the time of writing it looks like the week ahead promises significant highs and lows – not ideal for many of the recommendations that are waiting in the wings for application over the next couple of weeks. Another reason to think hard about which products can be applied together and which should really be applied alone. An extra day in the sprayer at this time of the year may seem like an unnecessary inconvenience, but if it means your applications are more effective it’s got to be done.

And what about disease? There has been the odd winter wheat crop that, due to variety susceptibilities and perhaps also drill date, has required an early dose of triazole chemistry to control yellow rust. Apart from that, the main disease I am seeing is Septoria, which has crept up lower leaves and needs controlling.  The mild winter we have had means that in my opinion, our T0 applications are equally, if not more important than, our other timings. We need to take the opportunity to make a robust start to spring disease control, as well as considering the use of PGR’s to encourage rooting and tillering to make sure we are not chasing problems into the season.

Those of you who have known manganese deficient patches will be well aware of the need to get onto the land ASAP to resuscitate crops that in places are on their last legs. Even if you have already managed to get an application on this spring you’ll probably want to get a second dose on sometime soon. You have options in terms of products – liquid formulations of manganese nitrate or sulphate, or the powder formulation of manganese sulphate. Everyone has their favourite; the nitrate formulation is useful for rapid uptake, the powdered sulphate formulation contains a higher loading of manganese. Make your decision as technical as you like, as long as the crop gets something!

OSR crops have definitely been targeted by flash mobs of pigeons since my last column. Keep shooting them; they really do make a lovely casserole. Several crops are starting to grow away; one farmer could see a visible difference in his crop after just one day of sunshine: from prostrate growth to visible stem elongation. Depending on how advanced your crop is (GAI’s presently range between 0.8 and 2.2 in my area) you may be planning an early stem extension PGR product, which could be worth its weight in gold with the high risk of lodging, otherwise you’ll probably hang on for the yellow bud timing.

Nitrogen plans may well require revisiting to take into account the mild, wet winter. The quality of your soils in terms of organic matter will contribute considerably towards your farms ability to hold onto nutrients, however Soil Mineral Nitrogen (SMN) results across the board are undeniably low – does this suggest that many of our organic matter levels are low too?

On the other hand we are being warned against encouraging lush, forward crops into lodging by applying too much nitrogen too soon. SMN cores taken at our local heavy land trials site demonstrate the huge losses of N over the wet winter; in October 96 kg N/ha was available in the top 30cm profile, results last week took this figure down to 7.5kg. These extremely low SMN results do pose the question as to whether forward OSR crops are indeed heading towards lodging, or if they are being forced into early maturation through stress due to lack of nutrition.

I think it remains questionable as to what we‘ll be able to apply to our crops in the short term. It is still only early March and there is every chance that we could step into a ‘Blackthorn Winter’ cold snap and put some or all of our plans on hold for a few days, or weeks.

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