Pulse diseases thrive in warm and wet weather

Pulse crops are expressing symptoms of disease in warm and wet conditions, with growers urged to react with fungicide sprays to protect yield.

Sean Sparling is seeing high and aggressive levels of chocolate spot in winter beans, while downy mildew is evident in his spring bean and pea crops.

Chocolate-Spot2

 

Tip of the week

“To ensure optimum biomass production and return on investment from cover crops, maximise the capture of solar radiation by drilling as early as possible and treat them as a ‘crop’.”

Richard Harding, Procam

Procam’s Richard Harding is using metalaxyl-M to tackle his own spring bean downy mildew infections further south.

Mary Munro reports a state of shock from the Scottish farming community after the EU referendum result.

However, it is business as usual in the field as she evaluates how varieties have performed this year, with wheats Revelation, Graham and Crispin looking good.

See also: See the archive of all our agronomist reports

In the West, Antony Wade discusses the practical benefits of undersowing maize with cover crops to reduce the environmental effects of growing the regionally important crop.

He also reports high fusarium risk and waits to see if sprays have provided adequate control.

Mary MunroNorth: Mary Munro

Strutt and Parker (Perthshire)

This piece should have been written in “getting-back-to-normal” mode following four days at the Highland Show – instead, the Scottish farming world is in a state of shock at the outcome of the EU referendum and all the implications it carries, including the extra political connotations for Scotland. The next few years will not be dull for those of us involved in business consultancy.

Out in the field, wheats are at the head-spray stage and my recommendations are geared to keeping yellow rust at bay.

It has popped up in the weaker varieties, so a bit of eradication was required in some crops, and T3s will all contain a strobilurin with a good triazole.

We are now into the season for open days and crop demonstrations, and it is always interesting to see how varieties performed. The soft Group 4 distilling varieties are important for us.

Myriad is weaker on disease than I would have liked, but Revelation is looking clean. Revelation is perhaps a bit too late for Perthshire, but the +3 rating is not so much of an issue in East Lothian. With 14 hard Group 4s on the Recommended List, it is good to see some excellent disease ratings on new varieties such as Graham and Crispin.

Like Crop Watch contributors in other parts of the country, I have seen more grassweed issues this season, which is annoying.

Brome is a constant problem in the end rigs, but this year the treatments have not been so effective as usual, and I have also seen annual meadowgrass in spring barley beyond a tolerable level. Some adjustments will be made next season.

Richard-HardingSouth: Richard Harding

Procam (Sussex)

Here on the South Downs, it has not exactly been a settled June, with at least one sprayer I know getting stuck trying to apply a late post-emergence herbicide to forage maize.

We certainly don’t have a shortage of moisture holding back grainfill in cereal crops and growth in forage crops remain unhindered too.

Overall, crops are still standing well despite some very heavy and sporadic storms.

The wet conditions have maintained concerns about disease suppression and whether a T4 fungicide may be required for some early-drilled crops. Septoria and yellow rust could still pose a problem, with mildew now building on the lower leaves.

Product choice in cereals is limited due to few being approved for late applications. Generally, chlorothalonil has a cut-off of GS65 – flowering. So fungicide choice will be based on tebuconazole and prothioconazole where needed. Both are able to be applied up to GS71 – grain watery ripe.

Many of the forward oilseed rape crops are now beginning to turn and starting the move towards desiccation. In later-developed crops and where not already applied, an application of pod sealant such as Mesh is now being made.

Disease levels in winter beans have been particularly high in many crops, despite robust fungicide programmes, while downy mildew and chocolate spot are building up in spring beans and getting to high levels in some crops.

 

Metalaxyl-M is being used under an extension of authorisation for minor use (EAMU) for downy mildew control where levels get to more than 25% plants infected.

Sparling,-SeanEast: Sean Sparling

AICC (Lincolnshire)

Another month down and June has been something of a damp squib here in Lincolnshire – more like a soaking wet squib, actually.

Catchy weather and rain has unfortunately coincided with wheat flowering and therefore issues with fusarium ear blight may well be looming large.

Ear-wash sprays are now complete and were largely applied within the crucial 48 hours between growth stages 61 and 63.

Every year is different, but if we learned anything from 2012, it was that subsequent T4, T5 and even T6 fungicides are not only contrary to product labels (many fungicides have a cut-off timing of GS65), they are also a waste of money when it comes to controlling ear diseases.

The news that there is now emergency clearance for Biscaya (thiacloprid) on sugar beet for leaf miner gives us hope that there is at least something we can do to stop the visually devastating leaf loss – albeit a very expensive something.

Spring beans are showing rapidly increasing levels of chocolate spot thanks to the warm, thundery and wet conditions and it appears to be turning aggressive – a few weeks earlier than we would normally expect it to do so.

The weather is also causing increasing levels of downy mildew to appear in spring beans and peas, so suitable fungicides are being applied as and where necessary.

With the restriction of only one application of pirimicarb (for example, Aphox) on pulses, bruchid and early aphid insurgents are being dealt with using pyrethroids (taking bees into account with application). We will include pirimicarb next time through to deal with black bean aphids as and when they colonise.

Antony-WadeWest: Antony Wade

Hillhampton Technical Services (Herefordshire/Shropshire)

Wheat crops romped into flowering and rain and humid conditions coincided with anthers present – both factors creating ideal conditions for fusarium infection.

Most of my T3 recommendations were on farm and some managed to spray ahead of the heavy showers, while others managed to grab a spray window on the odd less showery day, but only time will tell whether this will give us adequate control.

As well as fusarium, the rainfall we have recently experienced will increase the spread of septoria infection on leaves. As we all know from recent history, both of these diseases can have a significant effect on final yield.

Locally, we escaped the worst of the torrential downpours, so barley and oat crops have not been battered down and are still standing. On my travels, however, I have seen some lodging and again this will affect yield. This is despite a fairly short crop year and shows you can’t insure against extreme weather.

Maize enjoyed the warmer conditions earlier in the month and started to romp away. Post-emergence herbicides were necessary, as too much weed had come through the pre-emergence.

I am involved in a number of initiatives to encourage growers to try undersowing maize with a cover crop to stabilise soils and reduce sediment and nutrient loss both pre- and post-crop harvest.

By demonstrating simple and effective “in-crop” establishment techniques, along with additional benefits of qualifying for environmental focus areas, providing a winter-grazing opportunity and building soil organic matter show that protecting our soils is a practical option, even in this high-risk crop.

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