Humber and Oakley are the two newest wheat varieties with a significant market share. Mike Abram finds out how to manage them through the spring.
Treat Oakley virtually the same as you would Robigus for disease control, and you won’t go too far wrong, says Bob Simons, an independent consultant, who provides agronomy advice for the variety’s breeder, KWS UK.
“It is a lot better than what Robigus was but it will pay to adopt a similar strategy.”
Likely diseases risks are eyespot, rusts and septoria, explains Mark Hemmant of Agrovista. “It gets a little bit of everything, although it is not as exposed to rusts as its Claire x Robigus parentage might suggest. Last year, rust tended to come in later.”
Even so, he suggests using a rust-active triazole at T0, plus chlorothalonil. “Even where rust does come in later, you will get a benefit from a T0 triazole.”
A metrafenone-containing product, such as Capalo or Ceando, is a choice both are comfortable with, in view of Oakley’s eyespot risk. “Split dosing in high-risk eyespot situations is worthwhile,” says Mr Simons.
UAP‘s Chris Bean would also choose the metrafenone route at T0. He is a firm believer in the timing. “My starter for 10 is a T0 – I’ve been doing it for 20 years now.” On average in UAP trials it has been worth an extra 0.5t/ha, he claims. “It is fully justified.”
At T1 Tracker and prothioconazole are strong options. Both products cover eyespot, septoria and rusts, although, Proline can sometimes come under brown rust pressure when a T0 hasn’t been applied, Mr Simons notes.
A strobilurin fungicide might be useful where rust is an issue at T1, he adds. “It can give a noticeable benefit, but with the restriction on application to two, some people will prefer to keep them for T2 and T3.”
All three advisers agree a rust-active strobilurin, mixed with a triazole should go on the flag leaf. “This is when you are most likely to see brown rust on Oakley,” Mr Hemmant says.
As ever on a feed variety, the application of an ear spray is open to debate. Mr Simons acknowledges if the weather in May is hot and dry, growers might not consider it.
But Mr Hemmant says brown rust risk might encourage growers to spray. “Its fusarium rating is provisionally a four, so in areas of high risk you might also want to cover that. But to do it properly costs a lot of money so it is not easy to persuade growers.”
Humber, if anything, should be easier to manage. It is short and stiff meaning growth regulator need should be less (see panel), while it has good all round disease resistance.
“It did get a little bit of brown rust last year, but it came in late,” Mr Simons recalls.
Typically Humber has been fitted into an early drilled slot, or as a second wheat. The former encourages septoria, while both, theoretically, increase the risk of eyespot.
However, Humber’s good eyespot resistance – it’s rated an eight – means Mr Simons is less concerned about that disease and advises growers target septoria and mildew and mildew at T0, if they apply one. Wheat prices of £150/t make it easier to justify that timing this season than, perhaps, when prices are lower.
He advises a low rate triazole/chlorothalonil plus metrafenone (as in Flexity) for mildew, which will also have an effect on eyespot. “It is a lot easier to get on top of mildew early than chase it later,” he warns.
Mr Hemmant would go with a straight chlorothalonil. “The triazole is mostly for rusts. Humber is one of the few varieties where there isn’t a massive rust risk.”
All the same it should give a response to a T0, Mr Bean suggests. “In our trials both Humber and Oakley gave around 0.25-0.3t/ha response to a T0.”
At T1 Mr Simons suggests an Opus-based spray targeting septoria, while Mr Hemmant would use Ceando, for its combined mildew and septoria activity, plus chlorothalonil.
He would use a strobilurin with physiological activity at flag leaf, in combination with a septoria-active triazole. “You only need a tiny response at current prices to justify a strob’s use.”
Ear treatments will depend on the season. “It hasn’t got a big rust risk, but it might need topping up for septoria control.”
Both Oakley and particularly, Humber, shouldn’t suffer from lodging
Neither Humber nor Oakley are particularly high risk varieties to lodge, according to Syngenta profiling.
Indeed, as the HGCA Recommended List confirms with nine ratings for standing power with and without growth regulation, Humber is just about the least likely variety to fall over.
“It is one of least worrying varieties,” Syngenta‘s Simon Laidler confirms. “From our trials it is definitely low risk.”
Even so, he would recommend a growth regulator application of chlormequat plus Moddus (trinexapac-methyl), not least because PGRs usually produce extra yield, even in the absence of lodging, he says. “With the economics today it is a reasonably cost-effective input.”
Early-drilled Humber may well be more at risk from lodging, according to KWS wheat breeder Mark Dodds. “Varieties get taller, so it will need a programme.”
In very high risk situations, early drilled on fertile soils, an early split of PGRs might even be worthwhile, Mr Simons suggests. “Otherwise I would do an early application with an option of Terpal at GS33-37.”
Oakley is slightly more prone to lodging, Mr Laidler says. “It doesn’t have any particular risk factor, but it does have the potential to lodge when pushed hard.”
For this variety he recommends 0.2 litres/ha of Moddus plus 1.25 litres/ha chlormequat, or an early 0.1 litres/ha Moddus at GS30 followed by 0.1 litres/ha + the chlormequat at GS31. “That worked well in trials last year, particularly on Alchemy.”
Mr Hemmant agrees a split approach to growth regulation would be more likely with Oakley, although he would split doses of chlormequat, with the second one including with Moddus or Canopy (?).
A more routine early split, with again the possibility of a later Terpal application, is also recommended by Mr Simons. “If there is a lot of yield you need to protect it.”
- Capalo – epoxiconazole + fenpropimorph + metrafenone
- Ceando – epoxiconazole + metrafenone
- Tracker – boscalid + epoxiconazole
- Proline – prothioconazole
- Flexity – metrafenone
- Opus – epoxiconazole
- Moddus – trinexapac-ethyl
- Canopy – prohexadione-calcium + mepiquat chloride
- Terpal – 2-chloroethylphosphonic acid + mepiquat chloride
Suggested programmes at a glance:
- T0: Capalo / Ceando + chlorothalonil
- T1: Tracker or Proline + chlorothalonil
- T2: Rust-active strobilurin + triazole
- T3: Depends on season
- T0: Chlorothalonil +/- triazole / Flexity
- T1: Opus / Ceando + chlorothalonil
- T2: Strobilurin + septoria-active triazole
- T3: Depend on season