Speculate to accumulate with fungicides
There has been an unprecedented number of late drilled crops this year, many of which are backwards and will need a big effort to pull them out of the winter.
Advice from experts is that fungicide programmes will be key in getting the most out of the crops and farmers cannot afford to cut back.
Last season showed yet again that SDHIs have become the most critical part of the programme offering disease control as well as yield benefits.
This year it will be a fine balancing act to use this chemistry responsibly but robustly enough to cope with any disease pressure that comes growers’ way.
Yellow rust has already been spotted in various regions across the county including Cambridgeshire and Lincolnshire. Eyespot is a disease that will need to be closely monitored as will septoria – which agronomists warn is the real threat.
Independent agronomist Sean Sparling believes growers will encounter problems if they do not cater for all eventualities.
“The problem with the fungicide programme is you’re trying to predict what is going to happen in the four weeks between this spray and the next one so I think as far as I’m concerned you put on something that is robust enough to carry itself through and cover every eventuality.”
Bill Barr, Prime Agriculture Bedford
Prime Agriculture’s Bill Barr takes every season as a blank piece of paper and says being flexible will be key in reaching the right decisions.
“T0 will be triazole + chlorothalonil which will tackle things across the board.”
“At T1 I will predominantly be looking at boscalid + epoxiconazole + chlorothalonil, however on areas where eyespot is bad, we would drop the boscalid and go for a simpler triazole + chlorothalonil +/- a strobilurin.
Mr Barr suggests he may also put in some Aviator (bixafen + prothioconazole) at T1.
“T2 will be an SDHI – we did 99% of them last year and it was definitely be the right thing to do and it will be again this year.
“It will be a case of seeing how the season develops in terms of weather and disease and then with or without chlorothalonil or with or without a strobilurin a situation,” he says.
Mr Barr suggests prothioconazole will be the main part of his T3 programme with another addition depending on the season.
“A lot of it will depend on pricing, what we see in the field and varieties.
“Fungicides are an insurance policy. It used to be at T2 you would spend 50% of overall cost but now that’s 35 -45% and we spend a lot more at T1 because of the protectants and the triazole falling away slightly,” he says.
T2 will still be critical this year with septoria and rust the main disease worries. Mr Barr highlights that these are the strengths of the SDHI’s and in the absence of disease they still offer yield benefits.
“The trials from last year showed 0.7-0.8t/ha response and I think this would have been bigger if we had had adequate solar radiation,” he added.
Nick Wall Crop Management Partners Hampshire
Independent agronomist Nick Wall of Crop Management Partners says about 70% of his clients’ wheat was drilled and about 50% of that is normal and 50% would be backward.
“I would then divide up the chemistry depending on variety and whether they are rust susceptible. If they are rust susceptible they would get a T0 of 1litre/ha Cherokee (chlorothalonil + cyproconazole + propiconazole).
“For more resistant varieties it would be straight chlorothalonil and probably the later drilled varieties would be chlorothalonil with a mildewcide,'” he says.
At T1 Mr Wall believes chlorothalonil is a must. He targets eyespot and rust with boscalid with a possible triazole depending on the weather, with a possible strobilurin if rust is particularly prominent.
“At T2 I’ll be using an SDHI like last year. I think the jury is out for me whether at T2 Chlorothalonil benefits an SDHI but it would be 1.25litres/ha of Adexar on a rust susceptible variety and 1litre/ha Aviator on a septoria susceptible variety.
“Then we could add a quarter triazole or strobilurin to those depending on what happened. So we’ve got a core programmer and then we can bolt on and be flexible when necessary.”
Mr Wall will base his T3 programme around prothioconazole, but has also had success with metconazole in the past.
Sean Sparling, Lincolnshire
Most of Mr Sparling’s crops will get a litre of Amistar Opti (azoxystrobin + chlorothalonil) at T0.
“At T1 they will get either 1-1.5litres/ha of Tracker (boscalid + epoxiconazole) or 1litre/ha of Aviator (bixafen + prothioconazole) with or without Amistar (azoxystrobin) or Amistar Opti (azoxystrobin and chlorothalonil).
“It depends how the season pans out, but the basis of my T1 will be Aviator or Tracker.
“My flag leaf will either be 1litre/ha of Aviator or a minimum of 1.25litres/ha Adexar plus a strobilurin and that will be 0.35litres/ha of Comet (pyraclostrobin) based on previous year.”
At T3, Mr Sparling says the weather will again play a big part. If it is wet at flowering he suggests a robust dose of either metconazole or prothioconazole. If it is not wet at flowering he will favour tebuconazole.
Daniel King, South Lincolnshire
Daniel King farms 480ha in South Lincolnshire. Mr King got all his wheat in, but has a mix of backward and forward crops.
“I got them all in, but I’ve got crops that are very good and then crops that are very poor with perhaps only 50 plants/sq m.
“I’m looking at going with 1-1.5litres/ha of Cherokee (chlorothalonil + cyproconazole + propiconazle) at T0 with the dose depending on what conditions turn out to be like” he says.
For T1 Mr King will use 1litre/ha Tracker (boscalid + epoxiconazole) and 1-1.5litres/ha Amistar Opti (azoxystrobin + chlorothalonil).
“T2 I will be using some Seguris (epoxiconazole + isopyrazam) because I had a good result with it. Otherwise 1-1.5litres/ha of Adexar or 1litre/ha of Seguris. It will probably be variety dependent on which one I choose as well as cost,” he adds.
T3 will again depend on the weather for Mr King, but he believes prothioconazole will be at the forefront of this.
