What actions are growers taking to tackle the ever looming threat of disease and therefore mitigate some of the risk factors involved in managing winter wheat crops? CPM poses the question for this month’s Real Results Roundtable.
“You have to protect crops – there’s no point in waiting and seeing what comes because those days are long gone.” – GILES BENSON
By Janine Adamson
Farming is frequently coined a risk-laden business to be in, namely due to the impact of external factors which are beyond the control of growers and their agronomists. However, with this risk can come reward, often the case when it comes to maximising returns from one of the most profitable crops in the rotation – winter wheat.
Recognising that disease pressure is a significant threat to crop performance, this month’s BASF Real Results Roundtable focuses on the topic of disease risk management. To discuss, CPM brings together Northamptonshire-based farm manager, Giles Benson; grower and technical agronomist for BASF, David Hawcroft; and BASF’s agronomy manager, Andrew Smooker.
Giles manages Turney Partners Farming in Quinton – an arable and contracting business operating across 1100ha of combinable crops including winter wheat, winter beans and spring oats. David represents mixed farming enterprise G A Hawcroft in East Yorkshire, but also works within BASF’s R&D team, contributing to the firm’s trials work.
SPRING RECOVERY
Although the overall national picture is generally more positive compared with this time last year, Giles explained that for him in Northamptonshire, the weather conditions this year have been worse than what the farm experienced last season. “I’d say 80% of our wheat looks okay with the remaining 20% not so brilliant, mainly due to a really difficult drilling period again in the autumn.
“As such, we’re slightly worse off in terms of soil conditions than last year, although the weather has dried up since January.”
Giles added that having assessed the status of his crops and with the weather permitting, he’s applied nitrogen and sulphur in the hope of kick-starting spring growth. “Normally at this time of year I’d apply around 40-50kgN/ ha just to get crops moving, but this season, I’ve stepped it up to 70kgN/ha.”
In response, David highlighted that ensuring adequate crop nutrition and undertaking other management actions such as using Cambridge rolls on frost damaged areas, is what he perceives as the first steps in mitigating risk.
“On the farm here we have quite variable soils and with the cold January we saw a lot of frost – any lighter areas have particularly suffered. But we’ve managed to get across quite a few fields of wheat with the Cambridge rolls to press those roots in and hopefully boost the crop’s potential.”
He added that on lighter soils, he believes applying early nutrition is even more important. “I have to get a lot of my fertiliser on in good time to get crops in as good a condition as they can be, so if they do dry out, they can withstand some of the stress. I use the same principles with PGRs to encourage rooting.”
WIDER MANAGEMENT APPROACHES
Expanding on the point raised regarding ensuring optimum crop health, the Roundtable discussed the influence of alternative solutions such as biostimulants. Giles said while he recognises their growing popularity, he prefers to focus on fine-tuning crop nutrition.
“The past few years we’ve undertaken around 30 detailed grain analysis samples during harvest. This gives us a real breakdown of nutrient use efficiency and where we might need to tweak applications in the future.
“We’ve not seen any significant problems during that time, it seems to be where it should be,” he commented.
Andrew added that while the benefits of biostimulant products can be subtle, they can certainly play a role in creating more resilience and consistency within a crop.
Giles then shared that a key factor when it comes to fungicide performance has been the purchase of a new sprayer which has vastly improved his application timeliness. “We can spray around 600ha in 2.5 days, often in windier conditions than most, purely due to pulse-width modulation (PWM) on our Bateman sprayer. It’s revolutionised application because we can reduce drift by dialling in different pressures and droplet sizes.
“Consequently, our number of suitable spray days has increased by a lot, and we’re far more accurate in what we’re applying,” he said.
THE ROLE OF THE T0
Having heard that Giles has 50% of his winter wheat area down to Crusoe for milling specification, and with concerns regarding the variety’s brown rust score, David asked Giles whether he’d managed to apply all of the farm’s T0s last year.
Giles answered that he indeed was successful, and that he’s been a great believer in T0s for years. “You have to protect crops – there’s no point in waiting and seeing what comes because those days are long gone. With the competitive price of tebuconazole at the moment, it’s a no brainer in many ways. That’s been our strategy here for a number of years – treat crops early at T0,” he commented.
And even though he perceives the risk of brown rust to be lower this year – mainly due to more frost events in his area – his aim is to make sure crops are clean from the off, given some are later drilled and therefore backward.
In reply, Andrew suggested that current concerns regarding brown rust risk may be due to fears of inoculum being present from last year, plus, an overall mild winter. “It’s still very early days but it does add to that picture of risk, and therefore the case for T0s and robust programmes throughout is only getting stronger.
“Some have discussed whether you see a difference in septoria control from a T0, but with the weather patterns we’re experiencing, plus having rust in the equation, it makes sense to utilise the early timing if you can,” he said.
David added that preventative action is key. “If you rely on curative activity from your fungicides, you really are asking a lot. But I believe it’s about assessing yield potential along with disease risk when deciding on crop inputs and spend, whether that’s fertiliser or fungicide for additional output.”
Giles pointed out that while he has a confirmed plan for T0 and T3, at the moment, T1 and T2 are still up for discussion. “With milling premiums and wheat prices both being squeezed, price will influence this somewhat,” he admitted.
FUNGICIDE PROGRAMMES
The discussion evolved to preferred approaches for later in the programme, with David highlighting that he’s pondering whether to include premium products earlier, and therefore reduce spend towards the end while still achieving septoria control across a more balanced programme.
Giles agreed that it’s something he’s also considered. “But at the end of the day, you want to keep the flag leaf and leaves two and three clean, so you have to be careful where you start to reduce spend.
“I understand the principle where if you’ve eradicated the septoria risk in the crop, you should be able to have a reduced investment later on, it just depends on how significant the risk of septoria is. Equally, if we reflect back to drilling date, we’re planting later as part of blackgrass management, so I hope that’ll effectively reduce pressure a little too.”
He added that if his drilling dates do have to come forward due to perceived weather constraints, he’d definitely consider realigning his fungicide programme’s spend.
Andrew suggested that during a dry spring, there can be talk regarding trimming investment at T1. But with limited options for curative activity and several high pressure seasons during recent years, it’s more likely to be around enhancing the robustness of earlier applications, he said.
“And of course, this season will be another with so many different scenarios regarding drilling date – anything from September through to late November and beyond – so there’ll be all manner of situations and spends.”.
All-in-all, the Roundtable agreed that growers can’t be in a situation where curative activity is relied upon. “That’s especially the case with brown rust – although tebuconazole does a good job of removing a lot of it from the leaf, it’s already down at the leaf axles and cycling very quickly,” stressed Andrew.
AZOLE FUNGICIDES AND REVYSOL
Referring to mefentrifluconazole (known as Revysol), Andrew asked the group what they thought about the azole class of fungicides. In response, David said he always strives to include Revysol in the programme; last season he used it in combination with Xemium (fluxapyroxad) and F500 (pyraclostrobin).
“You achieve good all-round disease control plus greening in one package – I think we can all agree that’s a reliable fungicide mix.”
Giles pointed out that it was also this combination which formed his T2 spray last year due to its overall cost-effectiveness during a high rust pressure year.
Andrew added that as well as covering septoria and eyespot, using these three actives in combination offers a robust rust package plus addresses any resistance management concerns. “We know the work the azoles have done during the years, with two key options – Revysol and prothioconazole. As such, we’ve relied heavily on prothioconazole for a long while, but it’s important to add in different azoles where you can, to preserve the chemistry.
Having used Revystar XE (Revysol+ Xemium) in the past, whether that be at T1 or T2 depending on the year, Giles said it’s worked well at either timing. “But I think we’ll be considering it at T1 for this season.”
In agreement, Andrew said Revystar XE has proven itself over a number of years in either slot. “However, getting the foundation of a programme right has become increasingly important during recent years, especially with the increasing threat of rust as well as some high septoria pressure seasons.
“While Revystar XE can still fit at T2, we do have another option now available for both wheat and barley in the form of RevyPro (Revysol+ prothioconazole). It’s a good tank mix partner option in wheat and provides flexibility in the fungicide programme.”
Andrew reminded that it must be used with another mode of action when targeting septoria, boosting the level of disease control and enhancing the performance of the mix partner. “So when you look at the potential of what RevyPro can achieve, it’s perhaps suited to a higher risk, higher input situation at T2, with Revystar XE in that T1 slot.”
To conclude the discussion, David shared that he has plans to use a Revysol-based mix at T1, possibly following up again at T2. “We have to take the season one step at a time and see how these crops respond.”
This article was taken from the latest issue of CPM. Read the article in full here.
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