Cereal fungicides T1 decisions

Key Points in this Technical Bulletin

• Need to build yield in backward crops
• Nitrogen use efficiency is enhanced by Xemium^®
• Tailoring your T1 input to crop potential and disease risk is even more important in 2020 due to the diversity of crop
• Check crops for yellow rust, particularly if not treated at T0
• New pathotypes add further complexity to yellow rust population
• Watch out for leaf number; very late sown crops have less leaves and at GS31 it can often be final leaf 3 emerging not leaf 4

What level of input is justified?

There are several different scenarios this season. There are a minority of crops that were sown in reasonable conditions before the end of October, the rest are later sown and at this stage of the season may look unpromising. This differential in crop is unusual and so requires a different approach from a standard season. The former have excellent yield potential and there is no reason why they should not perform well at this stage of the season. However, at the other end of the spectrum even the cleanest variety drilled in late February will still respond to some level of fungicide input. The challenge is selecting the appropriate input for the specific situation. This is where your agronomic skills come to the fore.

Nitrogen use efficiency

Soil mineral Nitrogen levels are low following the wet winter and making the most of the applied Nitrogen is vital. Xemium^® has been proven to have non-fungicidal effects on the crop including the improvement of the crop’s use of applied nitrogen, enhanced green leaf retention over and above disease control, more efficient photosynthesis.

New yellow rust pathotypes

<#text>Recent report from UKCPVS indicates that there are new yellow rust mutants out there. “Most varieties known to be relatively resistant to yellow rust (ratings 7–9) continued to perform well in the 2019 inoculated trials. However, some varieties reacted to a single isolate.The team identified 10 new pathotypes, including two on KWS Firefly and five on KWS Zyatt. Four of the pathotypes from KWS Zyatt included virulence for Yr8 and two of these appeared to carry avirulence for Yr1 and Yr9. It is the first time this virulence combination has been detected in the UK.”

https://ahdb.org.uk/news/new-pathotypes-add-further-complexity-to-wheat-rust-population

BASF recommendations

Adexar^® is the ideal choice for T1 in 2020 in many later sowing situations. It provides broad-spectrum and cost-effective disease control. It contains the strongest SDHI and the best of the older azoles, epoxiconazole, for rapid rust control. Yellow rust threat already reported even on “tolerant varieties”.

Where eyespot is a concern use Tracker^® either alone or in combination with Adexar^®. For the best crops Revystar^® XE provides the strongest option for Septoria control this year, which is balanced in efficacy between the two modes of action. The combination of the two active ingredients Revysol^® and Xemium^® give better Septoria control (and yield) than the individual constituents would supply alone; i.e. there is a synergistic effect from using them together.

This balanced design of Revystar^® XE is crucial for protecting both modes of action in the future, whilst delivering the strongest return on investment for the farmer. In all cases, the addition of CTL is recommended.

Adexar^®®, , Epic^®, Tracker^®Revystar^® XE and Revysol^® are registered trademarks of BASF. Adexar contains fluxapyroxad and epoxiconazole, Epic contains epoxiconazole, Tracker contains Boscalid and epoxiconazole, Revystar^® XE contains Revysol^® and Xemium^®. Revysol^® contains mefentrifluconazole. Xemium contains fluxapyroxad., Always read the label and product information before use. For further product information including warning phrases and symbols, you can refer to agricentre.basf.co.uk ^© BASF 2020 | All rights reserved