Crop Watch: Winter barley disease and Plasticine-like soils

Spring is perhaps finally here, and many growers are making good progress on drilling, except on heavy land, which is still too wet to work. Conditions are still challenging, with some fields having soil that more closely resembles Plasticine.

There is a huge amount of variability in crops, with forward wheats about to receive their T0 fungicides in the North, although they are still a week off in the South. Late-drilled crops are much further behind. Septoria is being seen in these more lush crops, along with stem browning.

Winter barley is also showing disease, with rhynchosporium seen in the North West, which will be tackled with the T0 spray to help maintain tiller numbers.

See also: How to manage weeds in potato crops without diquat

South: Iain Richards

Agrii (Oxfordshire)

The country may be shutting down worryingly, but our spirits are, at least, being raised by the spell of settled weather we’ve been waiting for since well before Christmas.

Our late October/early November-drilled wheats are responding nicely to their increased first nitrogen dressing, and won’t be needing their second split until they’ve finished tillering. It’s gratifying how much they have grown during the mild winter.

Those we couldn’t get in until the start of December are obviously well behind, but still looking reasonable.

T0s are a good week off and will vary more than usual, depending on the field. With the mild winter, we are seeing a good deal of septoria in our October/November drillings.

Other than where we have enough chlorothalonil in the shed, folpet will be our multisite here, combined with an azole.

The later drillings should be much cleaner by the time they get to mid-tillering – which won’t be for a while yet. So the emphasis will be far more management than disease-led – primarily plant growth regulators, phosphites, zinc and manganese.

Mildew threat
We will be very wary of mildew, which can be so damaging to the much more important lower leaves. And we’ll be particularly alert to the threat from aphids, as many of these crops haven’t had any insecticide yet.

Also responding well to the arrival of spring are oilseed rapes on our lighter land. They’re racing into yellow bud, having had a late stem extension combination of prothioconazole and Toprex (difenoconazole + paclobutrazol) to boost branching.

Crops that have sat all winter in waterlogged ground are struggling, but slowly beginning to pick up now and will flower much later.

Thankfully, there doen’t seem to be quite as many flea beetle larvae as last year and they are not so high up the plant. Looking at the crop differences, I’m sure the waterlogging has done as much damage as the flea beetles. In addition, pigeons are still a problem on many of these later crops.

We have all our spring beans in and drilled the spring barley on lighter ground. Pea drilling will follow on from the barley on the lighter land farms.

There are, naturally, huge differences between soil types here. Aided by some useful frosts, ground that was moved in the autumn is working down nicely, with a light tickle ahead of drilling.

In marked contrast, heavier land that couldn’t be moved still isn’t workable. So, it’s going to need patience and particular care in cultivation. We know only too well how easily it can bake hard, given a couple of weeks of sun and drying winds.

With the forecast set to be reasonably fair, we have enough time to get in the 20% larger spring barley area scheduled this season.

North: Helen Brown

Hutchinsons (Cumbria)

I am excited to report that spring has finally arrived in Cumbria, signalled by the casting aside of wellingtons in favour of boots.

This spring/summer is likely to be a very difficult one for many due to the ongoing coronavirus situation.

However, the past couple of weeks have brought some welcome sunshine, and it is great to see growers in fields able to get on with land work, fertiliser/manure applications and cultivations ahead of spring cropping.

Drilling of spring wheat and barley has started in some cases and, after a long winter, it is worth considering sowing spring barleys earlier rather than later, as drilling date is key to improving yield potential.

Where conditions do not allow drilling earlier, consider increasing seed rates to counteract the reduced potential for tillering by the crop.

The only thing winter cereals have in common this season is that they are all very variable. Earlier-drilled crops are approaching growth stage 30 and T0 applications have started to be applied in these situations.

Early-sown barleys and wheats look very strong and on these, I am applying an appropriate dose of trinexapac-ethyl in the T0 spray for plant growth regulation and to reduce apical dominance.

Inevitably, the mild and wet conditions over winter mean there is disease present in winter crops, noticeably rhynchosporium in barley.

This is especially visible in forward crops with high plant populations. A fungicide application at T0 in winter barley is important for early disease control to maintain tiller numbers, as final ear numbers are directly related to yield. 

However, not all winter crops are so advanced, and weed control is the priority on some of the later-sown crops where autumn residuals were not applied, which is a common scenario this spring.

Nutrition is also important in these situations to get the crop moving. These crops have lower disease and lodging pressure.

However, they also have lower yield potential, and it is important to manage crops accordingly this spring. Nitrogen use should be based on yield potential, not on historical use, but do consider the N status of soils

East: Sean Sparling

AICC/SAS Agronomy (Lincolnshire)

With 14mm of rain since my last Crop Watch piece, and a brief three-day spell of what we believe may have been summer last week, spring drilling is well and truly under way at long last.

We’ve managed to get fields sufficiently dry to drill, although in many fields, the clods are like rocks on the top and sides, but malleable within and beneath. This apparently is as good as it’s going to get this spring in Lincolnshire.

In winter wheat, yellow rust and septoria are easy to find, along with widespread stem-based browning, which is duly noted.

But the T0 is as likely to be used to correct the widespread endemic nutrient deficiencies as it is to suppress, then protect, against further disease spread. There is plenty of chlorothalonil on hand to help with that.

Strobilurins with trace elements seem the obvious T0 choice. Growth stages of winter wheat vary between emergence and growth stage 30.

Spring drilling
Spring cereal drilling continues apace as time to complete the job rapidly runs out. Many people have 7 April firmly fixed in their mind as the date to put the drill away but, as we all know, conditions are more important than calendar date in this job and the phyllochron (time interval between leaf emergence) governs all.

We would all do well to remember spring 2018, when cereals drilled at the end of April produced forage and little more. About 120-odd growing days are required – squeezing 120 days into 90 didn’t work then and won’t work now, so once you hear that cuckoo…

Sugar beet drilling is well under way into what looks like good conditions if you squint, but which, as you get closer, resembles Plasticine over Swarfega – only time will tell if the beet seed thought that was a good idea.

OSR is showing first flowers in the rare minority of good crops, and there are still some fields where you have to get on your hands and knees to make sure the plants are still there.

Rape winter stem weevil is more widespread than I’ve seen in 30 years – but still, at least I have some toilet rolls left. Onwards.

West: Stephen Harrison

Avon (AICC/Southwest Agronomy)

The proverb March comes in like a lion and goes out like a lamb has a new twist this year. March swam in like a salmon and is riding out on a cloud of dust like a camel.

The dry spell has been welcome as it allowed long-awaited spring drilling to proceed apace.

However, the picture has not been so bright for those late-drilled crops on heavy soils. A capped soil surface, poor rooting and a large night and day temperature range have left them struggling to grow and respond to nitrogen fertiliser. 

I suspect the spring crops drilled in better conditions will produce improved margins.

Where attempts were made to redrill in one of the few windows over the winter, results are poor. I suspect this may be due to undressed seed scooped from the barn carrying a high fusarium load.

In good conditions, the effects are less pronounced, but if you put the crop under pressure, performance sharply tails off, so I always advocate testing farm-saved seed.

The picture is brighter on lighter soils, where good responses to nitrogen are apparent.

As agronomists, we are truly fortunate that during the coronavirus restrictions we can carry on our essential work to help ensure the nation’s food supply. We are visiting fields alone and communicating with clients online and by phone. 

New way of working
This new way of working is strange, as I greatly value face-to-face meetings, but we must not abuse the responsibility entrusted to us. We must cultivate this enhanced appreciation of British-produced food into a time beyond Covid-19.

Within Crop Advisors, our agronomy and buying group, we have held our meetings using video conferencing.  Seeing complex spreadsheets on our own desktop rather than squinting at a screen is much more effective, a pointer to how we may work in the future?

Through careful planning and ordering, we are seeing chemicals arrive on farm in a timely manner, although lead times are necessarily longer.

Stay safe and spare a thought for all those outside of agriculture who are working hard to help us.

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