Planning for barley

Compared to wheat, barley is more like a triangle with the lower leaves being a lot larger than the upper leaves. The result is that the lower leaves and the stem are far more important, contributing around 70% of a barley crop’s yield.

So when planning a fungicide programme for your barley crops, the focus should be on protecting the lower leaves.

How well do you know your farm?
Below is an editable PDF designed so that you can record simple but powerful data which will allow you to make informed decisions in future years.

What data do we suggest you record?
We suggest keeping it simple, focusing on plating date, crop growth stage and fungicide application dates. The aim is to strengthen your position in future years about the date GS32 will occur as this is a critical fungicide application timing for both autumn and spring planted barley. Once you know when this will occur, the other fungicide timings tend to fall into place. As your data set grows with time, it will be an invaluable record for you from your farm.

Would you be prepared to share?
Recording data on your farm in really important, but being able to benchmark how your crops perform alongside your neighbours and others in your region is invaluable. Use the downloadable PDF below to keep your own records or share your data by clicking ‘submit’ on the PDF and Bayer will collate the data and distribute findings from across the region.

Bayer Fungicide Disease Planner

Fungicide timing for barley

While the principles of effective disease control apply equally to barley and wheat there are two main differences:

  1. The importance of the lower leaves increases the importance of the early fungicide applications.
  2. Spring planted barley grows far quicker and therefore tends to require reduced fungicide inputs overall.

Winter barley

Barley Stage GS30


Autumn and winter planted barley crops often emerge from winter with significant infections of scald, net blotch and leaf rust on the lower leaves. At the same time, crops are still growing slowly and have several weeks to go before reaching GS32.

This is the reason why controlling disease with a GS30 application can be beneficial.

Barley Stage GS32


This application is the most important for autumn barley crops as all lower leaves have emerged.

These leaves, along with the stem, are the main contributors to barley yield and it is vital they receive a robust fungicide to protect them through to GS39, flag leaf emerged.

Barley Stage GS39


The flag leaf application for autumn barley crops is predominantly aimed at protecting the crop from attack by Ramularia leaf spot (RLS) and leaf rust (pg 25). In wet years scald can also remain a threat at this time.

RLS is a very aggressive disease, so applying fungicides at GS39, when the flag leaf has just emerged, is very important to achieving a good level of control. If the application is delayed, say to the traditional “tooth brush” stage (GS49), control can be reduced.

Barley Stage GS50


Applying a fungicide at GS50-55 is a relatively recent approach and one driven by the desire to maintain green leaf area for as long as possible.

Trials carried out by Bayer have demonstrated that this approach can be effective but care needs to be taken that product withholding periods are followed.

Spring barley

Apart from “spring barley” varieties that are planted during the winter, spring barley crops planted from August onwards grow rapidly. As a consequence they reach growth stages important for fungicide application quickly. Also, this rapid growth tends to limit yield potential.

Spring barley crops show excellent responses to fungicide application but the factors described above lead to a lower fungicide requirement than for winter planted barley crops.

Barley Stage GS31


This application is the most important for spring barley crops as all lower leaves have emerged. In addition, unlike autumn planted crops, an earlier GS25 application is not generally applied.

These leaves, along with the stem, are the main contributors for barley yield and it is vital they receive a robust fungicide to protect them through to GS39, flag leaf emerged.

Barley Stage GS39


As spring barley crops tend to reach GS45 quickly, and as Ramularia leaf spot (RLS) tends to be less of a problem, fungicide is often applied a little later than for autumn planted barley crops.

This application remains very important though as RLS, leaf rust and scald remain a threat at this time.

Autumn and winter planted barley

Any fungicide programme for autumn/winter planted barley should always include a GS32 fungicide. This is the critical fungicide to apply. Then there are three key points to consider (below).

  1. What is the disease pressure in my crop at the end of winter? For autumn or winter planted barley crops there is usually sufficient to warrant a GS30 application.
  2. What is the Ramularia leaf spot (RLS) threat. Again for most barley crops to not treat for RLS at GS39 would be a brave decision.
  3. Is the RLS threat sufficient to apply a second, SDHI fungicide at GS55? If you believe this to be the case, make sure you haven’t used foliar active, SDHI seed treatment as if you have this counts Systiva® as a seed treatment. As a foliar active SDHI seed treatment, the application of Systiva counts as 1 of the 2 SDHI fungicide applications permissible per season. If in doubt ask your agronomist for advice.

The programme below is commonly used on autumn or winter planted barley crops. Delaro, a mixture of prothioconazole (DMI fungicide) plus trifloxystrobin (strobilurin fungicide) not only conveniently controls all major diseases but doesn’t contain a SDHI fungicide. The use of Aviator Xpro, which is a mixture of prothioconazole (DMI) plus bixafen (SDHI fungicide), gives excellent control of RLS and leaf rust.

Barley Spray Programme Diseases Growth Chart

The programme illustrated below adds a second Aviator Xpro application to maintain control of RLS and prolong green leaf. This is mainly used in irrigated crops.

Barley Spray Programme Diseases Growth Chart

Spring planted barley

A straight forward programme based on a GS31-32 application of Delaro followed by an application of Aviator Xpro at GS39 is cost effective and easy to follow. It will provide excellent control of all key diseases – scald, net blotch, leaf rust and Ramularia leaf spot.

Barley Spray Programme Diseases Growth Chart