The AHDB Monitor Farm group at York recently discussed how farmers could reduce chemical input costs, with a focus particularly on T0.

David Blacker, host of the Monitor Farm in York, spends almost £60,000 a year on chemicals at the moment, across his farm. For winter wheat with black-grass pressure this is £245.19/ha and for winter OSR £261.43/ha.

During the meeting, Jonathan Blake, ADAS, gave expert insight into disease control and yield responses.

He said: "Let's take a wheat variety like Grafton. With a disease rating of 5, septoria control is key. If your T1 and T2 strategy is robust, you don't necessarily need a T0. Certainly, if you haven't got problems with rust, you can legitimately think about cutting out a T0.

"You need to think carefully about why you're applying a T0. If it's because of active yellow rust, then T0 is still very important. But, if you've just got septoria, then fungicides at T0 would have very little impact on yield. The biggest yield benefit comes from a T2 spray."

Data from Teagasc has shown that T0 applications have no significant impact on yield, unless yellow rust is present. However, the AHDB Wheat Disease Management Guide correctly indicates that active brown rust, yellow rust and mildew in wheat could warrant a T0.

Jonathan Blake: "A final warning, however, is that the difference between treated and untreated varieties varies hugely between trial sites across the UK, even with the most disease-resistant varieties."

AHDB Recommended Lists (RL) information is based on multi-site and multi-year trials information and help highlight the difference between treated and untreated varieties and will show the kind of yield response that fungicides can have. RL Harvest Result information provides an insight into the regional variability in yield between treated and untreated varieties.

Nitrogen and nutrient management

At the meeting on 28 June, the group looked at one field in first wheat (Grafton) after beans. Due to the cold, wet spring, the field had had little and often N applications. Farmers at the meeting discussed the various approaches to nutrient applications, and the effect strategies would have on the yield.

Jonathan Blake said: "In a wheat crop you generally don't harm the crop by holding N back until growth stage 30. Once a canopy has formed that is of a sufficient size, yield in wheat is determined by the top three leaves: the number of grains it sets are determined at flowering, by the resources available to the plant."

In addition to this, recently David carried out nutrient profiling (P, K, Mg) of every inch of soil down to a depth of 12 inches, in a field of heavy clay loam soil that had been min-tilled. He found that there was a noticeable concentration of nutrients in the top four inches, and that soil pH dropped to 6.0 between inches 5 and 9.

"The challenge is to manage nutrients so they're not bunched up. How do I get the nutrients to spread out more evenly in the soil profile? This small experiment also highlights the fact that we don't necessarily know where the nutrients are."

Get involved with the Monitor Farm

David Blacker said: "We've had a very good programme throughout the year, starting with soils and organic matter with Liz Stockdale. Next year we'll carry on this theme, and also look at managing grass weeds throughout the whole rotation."

The next meeting is on soils and cultivations with Philip Wright on 2 November 2016. For more information, or to attend the York Monitor Farm, contact Judith Stafford, judith.stafford@ahdb.org.uk.