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Sam Harvey

Find out about Bayer’s advice on some agronomic decisions in April

Article overview

In a busy month for arable growers, Sam Harvey outlines potential priorities for April in East Anglia.

Crop Progress

Writing a blog in mid-March that is relevant for April is always going to present a challenge, following the past six months weather makes it even harder to guess what April will bring. Constant rain since mid-October last year, with approximately half our annual rainfall in the last couple of months, there will be plenty to do when it dries up so prioritisation will be key.

Sam’s agronomy tips for April

1. Be careful around your timings of T0s and T1s in wheat

Although there are some good-looking crops, they’re among a majority of backward and/or late drilled crops. Multiple stress factors, such as standing water, nitrogen deficiency in conjunction with later drillings will result in crops accelerating very quickly which means it will be difficult to hit all timings and some growth stages may not occur.

Intervals between applications will likely be tight and the potential for damage high. There may be scenarios where T0s won’t be relevant but remember that the risk of yellow rust will be higher with later drillings.

Likewise, correct T1 timing to protect leaf 3 is fundamental and underpins the whole fungicide strategy. Getting it wrong can be a recipe for getting it wrong for T2.

If contact herbicide applications aren’t complete, feel free to get in touch for guidance – late applications, especially on late drilled crops in a late season are always a concern and decisions need to be taken on a case-by-case basis.

2. Target leaf three fully emerged for T1s in wheat

T1 can be the trickiest timing to get right - target leaf three when it’s fully emerged. The only way to identify which leaf has emerged is to dissect plants – get it wrong and disease control will be compromised later.

Ascra® (bixafen + prothioconazole + fluopyram) will likely suit many situations this season at T1 with its broad-spectrum activity to cover Septoria, yellow rust, mildew and eyespot.

At 1L/ha minimum it provides yellow rust control alongside strong Septoria activity through its dual complementary SDHI loading. It will also give good protection against stem-based diseases and mildew to complete its all-round broad-spectrum profile resulting in best return on investment.

It's worth remembering that a thinner crop stand, will contribute proportionally more to yield from the lower canopy compared with a thicker canopy. The physiological benefits of Ascra applied at T1 are likely to pay dividends here this year.

Remember that bixafen-containing products increase nitrate reductase activity improving nitrogen use efficiency, which is part of the physiological benefit, and this will be particularly useful this season.

Also the physiological benefits deliver yield in the absence of disease if it goes dry for a prolonged period. As with all the Xpro range the Leafshield formulation gives excellent rainfastness in minutes – useful in catchy conditions.

The Leafshield formulation is also a component of Vimoy® + Proline® co-pack available this season for the first time following authorisation last October. This is a physical co-pack that contains the new active isoflucypram otherwise known as iblon.

Vimoy used at a minimum rate of 1l/ha with Proline at 0.5L/ha will provide the strongest broadest spectrum disease control where crops warrant the input, with exceptional activity on yellow and brown rust in conjunction with excellent Septoria activity. Iblon® also generates enhanced physiological greening benefits beyond bixafen, creating a greener canopy for longer.

3. Maintain tiller numbers in winter barley with a T1 fungicide

Maintaining tiller number in winter barley is more important than wheat. Maximising the number of ears is what drives yield, and disease infection at this stage will cause the plant to abort tillers limiting yield.

Some crops may well have had a T0 of prothioconazole, but in any-case T1 gives the biggest response to fungicides. 0.6L/ha Siltra® Xpro (bixafen + prothioconazole) provides an extremely reliable option for most situations. Ascra® Xpro at 0.9L/ha is an option also but can only be used at a single timing in crops and can bolster net blotch. Both options are suitable for malting crops.

4. Protect oilseed rape crops

There are some reasonable crops of oilseed rape and forward autumn growth combined with mild wet weather may have encouraged light leaf spot and its crucial to keep this off the buds. While Sclerotinia isn’t a big problem most years, when flowering and petal fall coincides with optimum conditions for the pathogen infection it can be a big yield robber.

An application of Aviator® (0.75 L/ha) is the best all round option from green bud through to mid-flowering, covering not only Sclerotinia but also light leaf spot. It also provides physiological benefits to the crop in the absence of disease, prolonging flowering. In farmer strips trials it has increased yield by 0.25 t/ha on average versus the farm standard consistently over the last few years.

5. Two early season potato products a must have

The low dose, operator-friendly liquid nematicide Velum® Prime (fluopyram) provides good yield protection and PCN population management and is a useful starting point for all programmes. In low pressure sites it can be used alone as an affordable option, while under higher pressure use in conjunction with a granular nematicide at either half or full rate of the granule.

With application either on-planter in-furrow or as an overall spray and then incorporated it can fit into most systems without too much hassle.

Pre-emergence product Emerger® (aclonifen), which provides a strong backbone for weed control in potatoes, ideally should be applied at least seven days before the crop emerges. It gives good all-round weed control, especially of Polygonum, Chenopodium, Brassica species and nettles. Add a partner, such as Artist (flufenacet + metribuzin) to provide robust grassweed control.

In addition, a label extension of Emerger for use in combinable peas and beans provides a very strong mix partner option at pre-emergence. As well as the wide range of broadleaved weeds it controls, the novel mode of action is shoot uptake and therefore less affected by dry conditions which will inevitably come.

6. Use FieldView to monitor and measure on-farm trials

Doing your own on-farm trials to compare inputs is a great way to see what works for you. Our digital platform FieldView makes that easy. FieldView brings all your data under one umbrella to enable better analysis and interrogation of data for better more informed decisions. If you’re interested in having a trial, please get in touch.


Ascra contains bixafen + prothioconazole + fluopyram. Vimoy containts isoflucypram. Proline contains prothioconazole. Iblon contains isoflucypram. Siltra contains bixafen + prothioconazole. Aviator contains bixafen + prothioconazole. Velum Prime contains fluopyram. Emerger contains aclonifen. Artist contains flufenacet + metribuzin. Ascra, Vimoy, Proline, Iblon, Siltra, Aviator, Velum Prime, Emerger and Artist are all registered Trademarks of Bayer. All other brand names used are Trademarks of other manufacturers in which proprietary rights may exist. 

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