How to keep wheat fungicide cost low and grow high yields

James Mayes’ aim is to grow high yields of winter wheat while holding fungicide spend to below a key benchmark of £100/ha.

His milling wheats touched top yields of 11.5t/ha last summer on the Essex farm he manages using well-tried and tested fungicide products.

He advises all the farms managed by farming company Sentry stretching from north Norfolk down to Dorset on fungicide use and considers £100/ha spent on disease control a good investment for the group’s eastern region farms.

“Our aim is to target a £90-£100/ha fungicide spend on our eastern region farms, which can obviously go up in a bad disease year,” he says.

See also: Winter wheat growers could consider missing T0 spray

Mr Mayes has reviewed Sentry’s strategy over the past few years, and split up the group’s farms into three regions – eastern, western and southern over the 20,000ha it manages.

Sentry facts

Sentry farms about 20,000ha from north Norfolk down to Kent and Sussex, with  most of its farms clustered in East Anglia and south-east England, and outlying operations in Dorset and Leicestershire.

It farms about half its land under contract farming arrangements and the rest under management deals or farm business tenancies. The business was started in 1972 and it has been employee owned since 1999.

Biggest yield robber

Septoria is the biggest yield robber of wheat overall, but in the eastern region the strategy is more rust-led, focusing on controlling yellow and brown rusts.

Fungicide applications are generally front-loaded to build up crop biomass, which has been proved to lead to higher grain yields for the group.

“We are looking to build big crops early in the season so they will hang on for longer and produce high yields,” he says.

James Mayes in crop

James Mayes

With a farm average wheat yield of 9.7t/ha across 325ha of milling wheat last year and a top harvest of 11.5t/ha, the strategy is clearly going in the right direction. Nitrogen use on his wheat is about 240kg/ha to achieved these yields.

Mr Mayes manages 800ha of arable land at Bentfield Bury Farm, near Stansted, three miles north of Bishop’s Stortford, while also giving agronomy advice across the farming group.

Disease-resistant varieties

The fungicide strategy begins with picking newer, more disease-resistant wheat varieties and managing the drilling date to start in the last week of September to limit disease developing in the autumn.

On his farm, this meant a switch to new milling varieties such as Skyfall, Zyatt, Lili and Siskin, away from old disease-susceptible feed varieties.

A wet August and September in 2017 meant drilling did not start until mid-October, which saw a built-in advantage of lower autumn disease pressure.

“The crops look happy this spring despite the heavy rain with very little rust, no mildew and some overwintered septoria,” Mr Mayes says.

Fungicide strategy

T0 Azole tebuconazole plus multisite protectant chlorothalonil

T1 Eastern region: SDHI boscalid, azole epoxiconazole and strobilurin pyraclostrobin (Nebula) plus chlorothalonil

T1 South and western regions: SDHI bixafen, azole prothioconazole and strobilurin fluoxastrobin (Variano) plus multisite protectant folpet

T2 Eastern region: SDHI fluxapyroxad and strobilurin pyraclostrobin (Priaxor) plus azole epoxiconazole and morpholine fenpropimorph (Eclipse) plus chlorothalonil

T2 South and western regions: Similar to T1, based on a choice of Variano, Aviator (bixafen-prothioconazole or Ascra (bixafen-fluopyram-prothionconapr/Bizafen )

T3 Eastern region: Azoles prochloraz plus tebuconazole

Building block

The building block of his programme is the first T0 spray, applied this year in the first week of April, despite the wet and late spring.

This treatment consisted of the multisite protectant product chlorothalonil plus the azole tebuconazole to control any rust in the crop.

“The T0 starts to build up septoria protection and dries up any active rust in the crop,” he says.

Costing about £10/ha, this T0 azole-multisite approach is a sound investment across crops in the eastern region, he believes.

Once the T0 is applied, this is a starting gun for the fungicide programme, with the second  T1 spray ideally applied three weeks later.

Choice of product

The T1 choice of product and rate is based on variety choice, weather and interval from the last spay, but the general approach is to use an SDHI fungicide, and only omitting this SDHI in late-drilled, thin wheat crops after roots where disease pressure is lower.

“Generally, we would be using an SDHI at T1 as it helps to build the crop canopy and biomass and hence yield,” he says.

His approach is to use the older SDHI boscalid with azole epoxiconazole, strobilurin pyraclastrobin and a multisite. The boscalid gives the bonus of good eyespot control, while the strobilurin gives a greening effect and encourages rooting.

“This has worked well for us in a rust-driven situation with an overall cost of about £35/ha,” he says.

Yellow rust in wheat crop

Further south and west, the SDHI choice is often based on a mix containing bixafen, azole prothioconazole and strobilurin fluoxastrobin. These formulations are being used for their perceived good rainfast qualities in these wetter climates.

Approach at T2 

During T2, the eastern approach is based on the SDHI fluxapyroxad, with pyraclostrobin, epoxiconazole and fenpropimorph being added.

This four-way approach provides protection against rusts, mildew and septoria. If required, a further multisite will be added to bolster protection, to give a total spray cost of £43/ha.

In the western region, the group stays with the T1 bixafen-led approach at T2 with a further dose of a multisite.

For the T3, Mr Mayes looks for an azole combination of prochloraz and tebuconazole, with the focus on controlling brown rust and fusarium costing about £10/ha, but if the disease risk is high prothioconazole would be used.