Crop Watch: Rising disease pressure and hungry crops

Days are getting longer, but there is no let-up in the forecast, with rain set to frustrate farmers as April approaches.

Some limited field work is being carried out on lighter land, but there is growing urgency to get fertiliser onto crops that have yet to receive any to save tillers, especially winter barley.

The wet conditions also mean there is plenty of disease in winter crops, with light leaf spot appearing on OSR, yellow rust in wheat, and high levels of mildew and/or brown rust in some varieties of winter barley.

See also: How two farmers are cutting back on fungicides this spring


Tod Hunnisett – AICC (Sussex)

Four weeks since my last report and apart from the fact that anything not waterlogged has continued to grow, (some of it without having had any fertiliser), nothing much has changed.

Oilseed rape (OSR) in particular grew 0.5m and turned yellow over a weekend in the middle of March, and frantic revamps of nutrient plans took place (not to mention fungicides/growth regulators).

Deep N tests (and healthy crops) have indicated a surprisingly high level of residual nitrogen floating about, despite the wet conditions. I can only imagine it has been the relatively mild conditions that have allowed continued mineralisation over the winter.

Interestingly, total rainfall has not exceeded previous years (I’ve seen local ponds larger in the past), it’s more that we’ve only gone more than two days without rain on about two occasions since October.


Fungicide planning has been a nightmare this season with senseless box-set offers. I haven’t spoken to a single person who likes them. A recipe for mistakes to be made.

Cereals are beginning to look a bit hungry now, and most (but not all) have had or are getting fertiliser. Disease risk is looking very high at the moment, so I can see some fairly chunky applications of first fungicide.

We can always cut back when we’re desperate for rain in mid-May.

As I write, I haven’t had a single seed of spring crops drilled. With rain forecast for most days this week, there might be some interesting conversations taking place over the next couple of weeks.

I’ve just looked at the long-range forecast and it’s talking about -2 to -3C frosts in early- to mid- April. That’ll be all we need – but I imagine we’ll deal with it as normal….

My thoughts go out to people up-country. We’ve had it easy compared to them. At least we have crops in the ground.


Antony Wade – Hillhampton Technical Services (Hereford/Shropshire)

I have now spent six months saying it must dry up soon and still all our hopes are being dashed, with 74mm in March so far.

The dry settled period desperately yearned for seems to be rarer than an English winner at Cheltenham.

And just like Cheltenham, it is certainly heavy going out on farm. Some growers have managed to get some field work done by taking the John Smith’s attitude in that it’s got to ’ave it.

A testament to how wet the season continues to be is that when a grower phones you it’s to tell you they have done some field work and not got stuck.

Fertiliser spreaders have been the priority to try to get a start on getting some nitrogen on all crops that are in need of a lift from being sat in saturated soil.

Many clients have polysulphate to deliver the crop’s sulphur requirements, but the delay in getting this on and slower release of the product means that foliar delivery of sulphur is having to be factored into the programme on these farms.

It is difficult to deliver enough sulphur through foliar application, but it may prevent crop becoming deficient and preventing nitrogen uptake.

Manganese and other trace elements will also be required to ensure cereals have nothing limiting when spring does gallop around the corner.

Oilseed rape

I very much believe that oilseed crops with a well-managed canopy are the best performing, but this season crops requiring growth regulation have been minimal.

More crops have required amino acids to try to pick them up, with rooting suffering in saturated soils and pigeon grazing reducing leaf area.

Light leaf spot is starting to show on leaves, but with the weather delaying spraying stem extension fungicides and some crops starting to flower, these are also having to cover early sclerotinia risk.

Spraying jobs are stacking up. Contact herbicides on wheat and barley that haven’t had any autumn herbicide or where grassweeds are tillering are a real priority now.

The delays mean resisting the temptation to cover many jobs in one tank mix is getting harder, but focusing on the priority target and not compromising control nor increasing the risk of crop effect in stressed crops has to be the overriding consideration, even if it means extra spray passes.

So I am sticking with contact herbicide alone with only the addition of elicitor as a start to disease control.

There is some September and early October drilled wheat that looks pretty good and is pushing GS30, but across the board of varieties, septoria is rampant.

Thoughts of spring drilling are still a distant dream in current soil conditions, although lengthening daylight hours mean that this can change rapidly if we can have more than a run of two days without rain.

The lack of prospect of spring drilling is making some growers stick with the patchy autumn crops, questioning why they should incur further cost for an average spring crop.

This season looks like it is to be heavy going to make arable crops turn a profit.

We are still hoping on a outsider coming up on the rails to surprise us with its performance after a slow start, but it is a steeple chase not a flat race so there is time yet.

Luckily in a mixed farming area growers have more of a spread bet with other enterprises – apples, beef, sheep and – dare I say – chickens. They have their own challenges, but look a safer bet at present.


Marion Self – AICC/Prime Agriculture (Suffolk)

Field conditions are generally improving as soils steadily dry, allowing growers to catch up with cereal fertiliser, grassweed and manganese applications.

However, the outlook remains unsettled and showers continue to cause frustration by further delaying spring drilling.

That said, there has been some progress where soils are drying more quickly due to soil type and/or cultivation strategy. 

Where the soil is heavy, wet and tight, more patience is required.

Time is ticking and in the worst circumstances growers are looking at poorer potential gross margins with maybe fallow or an appropriate SFI option being the best bet now.

Growth of winter crops is variable depending on drill date and how they have been affected by the wet winter.

Generally, crop growth is pushing on as soils become drier and plants are hungry to utilise nitrogen and other earlier applied micronutrients.

Indeed, where later drilled wheats were established in well-drained soils they are growing particularly well.

Although with smaller root systems their ultimate performance is highly dependent on soil moisture supply throughout the remainder of the season.

More forward September and October-drilled crops have reached or are approaching early stem extension.

These are now ready for early fungicide, plant growth regulation and broad-leaved weed applications as appropriate. 

Varieties susceptible to yellow rust should be monitored closely as damp, cool conditions have encouraged early infection.

In these varieties, yellow rust pustules can easily be found and sometimes established disease foci with both early- and late-drilled crops at risk. 

Barley disease

Drier conditions and nutrition have encouraged good recovery of winter barley crops; although susceptible varieties are often harbouring high levels of mildew and/or brown rust which need attention.

As barley reaches stem extension it will also receive early plant growth regulators, fungicides and herbicides.

OSR crops are also improving, with their present size also reflecting how wet soils are and the timing of early nitrogen applications. 

Where soil structure is good and cabbage stem flea beetle and rape winter stem weevil infestations are relatively low, there are some very nice-looking crops.

However, as with all winter crops this season there is a broad spectrum of growth depending on all of the above.

OSR crops have largely received the majority of the planned nutrition and are approaching early flowering stage.

Stronger crops have already had a plant growth regulator, light leaf spot and micronutrition treatment, with the level of input adjusted according to their perceived yield potential and the likely return on investment.

The few winter bean crops we have should be walked with a view to planning any cereal volunteer and broad-leaved weed sprays, before product label cut-offs based on growth stage come around.

Let’s be optimistic now, spring cereal, bean, pea and beet crops will be drilled as soon as conditions allow. If drilling spring pulses, be ready to apply the planned pre-emergence herbicides in time.

This is important as the efficacy of post-em options is limited and they are costly. No pre-em and there will likely be a mess of spring germinating weeds!

It’s likely that some spring cereals will be sown into challenging seed-beds. For these it is important to assess factors that affect crop safety (like seed coverage) before pre-emergence herbicides are applied.

If drilling spring pulses, be ready to apply the planned pre-emergence  herbicides in time.


Conor Campbell – Hutchinsons (Northumberland)

With April fast approaching, discussions about progress and a frequent change of plan have been a regular occurrence.

Some warmer and windier days have started to dry the lighter fields out and given us some hope, although this has been quickly dampened by more rain.

Last week saw some progress, with those that could venturing out with the first of the nitrogen onto all crops for many. A quick reminder, that non-inhibited urea can’t be applied after 31 March.

Something to also bear in mind is that urea, especially in cold wet soils like we have at present, is very slow to break down and be taken up by crops.

You could be looking at two-to-three weeks from the application date before crops start to see any benefit.

This is important to remember, as crops are hungry and that will only get worse. 

I am advising to think about going back in with the second split ammonium nitrate now, to kick these crops on and maintain tiller numbers.

Particularly in winter barley, as tiller numbers is the driver for yield.

By the time your second split timing rolls around, the urea will be there for the crop and thus save you a pass.

With spring workload greater than ever, it is difficult to know which way to turn and what to do first.

If nitrogen is on, then I think it’s important to let this take effect and allow the crop to pick itself up before looking at any spraying.

OSR disease

Light leaf spot is quite high in OSR crops, so a stem extension fungicide is important.

I would also use this opportunity to apply foliar nutrition and potentially look at a product to encourage branching, if the crop is thick and leggy.

I would certainly allow wheat crops to perk up before applying any grassweed chemistry and consider some foliar nutrition with this to help lessen the impact on the crop.

The advantage of the cold soils has been that wheats aren’t moving quickly, so growth stage 30 might be a little later than normal.

Barleys will want to shoot for the heavens, so some early plant growth regulator, nutrition and if needed, disease control, would be a good starting point, assuming you aren’t at growth stage 31 yet.

This helps to lighten the load of the T1 tank mix, which can get quite heavy if you’re trying to tackle everything in one go.

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