| Highlights from the 2004/2005 Winter Barley survey |
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- Total foliar disease levels were the lowest ever recorded during the twenty-three annual surveys conducted since 1981.
- For the first time since 1997, net blotch was the most severe foliar disease, followed by Rhynchosporium and powdery mildew respectively.
- Eyespot severity was higher this year than in any survey since 2000.
- For the fourth successive year, Pearl was the most common cultivar accounting for 47% of the sample.
- A higher proportion of crops were sown after September compared with the previous three years; the greatest numbers of crops were sown during the first two weeks of October.
- Consistently, as indicated in all but one of the previous surveys, eyespot severity was lower in crops sown after 14 October.
- Ninety-nine percent of crops were treated with a fungicide, more than in any previous survey.
- Each crop received on average 1.7 sprays, slightly lower than in 2004.
- The DMI fungicides were most popular group used. Ninety three per cent of treated crops received at least one application. Prothioconazole was the most popular active ingredient encountered.
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| National and regional severity of diseases |
| Of all the foliar diseases recorded, only the incidence and severity of net blotch was
higher in this survey than in 2004, mean levels on leaf 2 were the highest for 5 years. Levels of Rhynchosporium
have been decreasing since 2000, levels on leaf 2 were at their lowest since 1995. |
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| Fig. 1 National foliar disease levels (mean % area leaf 2 affected) |
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| The highest levels of net blotch were recorded in the west midlands region. However, the
disease was recorded more often in samples from the Yorkshire and the Humber region. Only the four major diseases
were recorded in every region. Rhynchosporium and mildew severities were highest in the north west region and brown
rust in the west midlands. Septoria nodorum was the only minor disease detected occurring in samples from Yorkshire
and the Humber, east midlands and the east regions. Selenophoma leaf spot and yellow rust were not found in this survey. |
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| Fig. 2 Regional incidence and severity of net blotch |
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| Eyespot severity increased compared to levels encountered between 2001 and 2004 but
were well below those recorded in the peak year of 2000. |
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| Fig. 3 National incidence (% crops) and levels of eyespot (mean % stems affected) |
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| The lowest levels of damaging eyespot (moderate + severe symptoms) were recorded in the
east and the highest levels in samples from the west midlands and north east regions. |
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| Fig. 4 Regional eyespot levels (mean % stems affected) |
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| Cultivar use |
| Pearl dominated the sample with 47%, followed by Carat with only 18%. Of the five most
popular cultivars, the highest average level of net blotch was recorded on Siberia with 2.2% of leaf 2 affected
whilst the lowest was on Sequel and Antonia with 0.2%. Levels of Rhynchosporium were highest on Antonia, brown rust
on Carat and mildew on Siberia. Since 2001 it has been recorded whether disease resistance was a factor when selecting
the variety, 33% per cent of respondents gave a positive reply, slightly less when compared with previous surveys. |
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| Fig. 5 Foliar diseases on main cultivars (mean % area leaf 2) |
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| Fungicide use |
| The DMI fungicides continued to be the most popular group applied to crops, with
the active ingredient prothioconazole applied to 56% of treated crops. Thirty three per cent of crops received a
single fungicide application and 63% received a two spray programme. Eighty nine per cent of crops received a
spray aimed at GS 31 with 64% of these crops receiving a subsequent application at GS 37 onwards. |
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| Fig. 6 Fungicide use: per cent of treated crops receiving applications from the major fungicide groups post emergence. |
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| Fig. 7 Fungicide applications during the growing season |
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| Sowing dates |
| The highest proportion of crops were sown during the first two weeks of October,
although nearly half of the crops were sown in September., Sixty-seven per cent of crops from the northern regions
were drilled by the end of September compared with 42% of crops from the other regions. Eighteen per cent of crops
were known to be grown from farm saved seed, a slight decrease when compared with recent surveys. Once again eyespot
was less damaging in the later sown crops. The incidence of BYDV, assessed in the field prior to sampling, was less in
crops where the seed treatment contained an insecticide to control aphid vectors. |
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| Fig. 8 Sowing dates of survey crops (%)
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