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Monitor spring barley rapidly approaching T2 timing

Spring Barley
26.05.2021

Following some much-needed rainfall in May, spring barley has seen a surge in growth and is now into stem extension and fast approaching T2 timing in many areas.  Over the past couple of seasons, disease development has been very low in spring barley.  However, this year could be different, so regular monitoring is recommended.

Disease resistance will vary with different varieties, LAUREATE is generally a cleaner variety, with the highest resistance to Brown rust and in the top 5 for resistance to Rhynchosporium. FAIRING has the highest resistance to Rhynchosporium, with a rating of 6.1.  In spring barley, Mildew resistance is common, but for all other diseases, the top ranked varieties still only have ratings classed as moderately resistant, and in high pressure situations a fungicide programme will still be required to maximise yield and most importantly for a malting crop, protect the grain quality.

 

Top 5 varieties ranked on resistance to Brown Rust

Top 5 varieties ranked on resistance to Rhynchosporium

LAUREATE

5.4

FAIRING

6.1

LG Diablo

5.2

Prospect

[6]

PROPINO

5.1

LAUREATE

5.7

RGT Planet

5.1

KWS Sassy

5.7

Sienna

5.0

Cosmopolitan

5.5

Source: AHDB Recommended List 2021/22

 

The dominant disease recorded over the past few years has been Brown rust, but the other main consideration for T2 will be for Ramularia, which may manifest itself after GS39 depending on site and weather.

For some crops, ‘T2’ will be a second spray, for others it may be the first input, so it is possible to tailor application timing accordingly:

  • Where no T1 fungicide was applied, target GS39 – (use rates at higher end of those suggested)
  • Where a T1 fungicide has been applied (around GS30), aim for GS49-55 (or 2-3 weeks after T1)

Key options will centre around SDHI and triazole combinations. The top 3 yielding varieties on the AHDB Recommeded List are Skyway, SY SPLENDOR and SY TUNGSTEN, they have lower or unknown resistance to Brown rust, so a product such as ELATUS Era, which is the strongest material on Brown rust as well as strong activity against Rhynchosporium, is a good choice to protect yield potential.  

There is no known varietal resistance to Ramularia, and recent chemistry losses have made the disease more difficult to control.  T2 is the key timing for Ramularia and protection can be enhanced with the addition of folpet (@1.0 l/ha).