| Highlights from the 2003/2004 Winter Wheat survey |
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- Total foliar disease levels were higher than in 2003, although levels were only half those recorded in 2002.
- For the fourteenth consecutive year, Septoria tritici was the most severe foliar disease.
- Eyespot severity was the lowest since 2001 and levels were only a third of those in 2000.
- The incidence of Fusarium ear blight was less than half of that in 2003.
- For the fourth successive year, Claire was the most common cultivar encountered, although proportionally it was less prevalent than in 2003.
- Eyespot severity was lower in crops following grass, an effect seen in the majority of past surveys.
- Sowing date remained consistent with recent surveys with 46% of the crops surveyed sown in October and 26% sown before 11 October.
- Ninety nine per cent of crops were treated with a fungicide, with 95% of treated crops receiving more than a single spray.
- Crops received an average of 2.75 sprays per crop, the highest ever recorded.
- The most popular fungicides used were the DMIs, 99% of all treated crops received at least one application from this group.
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| National and regional severity of diseases |
| Only Septoria tritici exceeded a mean of 0.2% area leaf 2 affected. |
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| Fig. 1 National foliar disease levels (mean % area leaf 2 affected) |
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| The highest levels of S. tritici were recorded in the northern regions. The incidence of the disease did not fall below 80% in any region. Only S. tritici and powdery mildew were recorded in every region. Yellow rust was only recorded in samples from the eastern region. |
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| Fig. 2 Regional incidence and severity of Septoria tritici |
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| Eyespot was less damaging than in 2003. However the proportion of stems showing slight symptoms increased compared with the previous survey. The percentage of crops receiving a fungicide application containing cyprodinil, flusilazole or prochloraz aimed at GS31 is still declining with only 15% of treated crops receiving applications of these ais. |
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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 south west and the highest levels in samples from the north west region. Severe eyespot was recorded in all regions with the highest in the east. |
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| Fig. 4 Regional incidence and levels of eyespot (mean % stems affected) |
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| Nationally recorded levels of Fusarium ear blight symptoms were well below those of 2003. However the incidence of ear blight symptoms was higher than in either 2001 or 2002. |
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| Fig. 5 National incidence and severity of Fusarium ear blight symptoms |
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| Fig. 6 Regional incidence of Fusarium ear blight symptoms |
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| Cultivar use |
| Only two cultivars, Claire and Consort, each accounted for more than 10% of the sample. Together with Malacca and Solstice the four cultivars comprised 46% of the survey. Of the nine most popular cultivars, the highest average level of S. tritici was recorded on Consort with 8% of leaf 2 affected and the lowest on Hereward with 0.7%. |
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| Fig. 7 Severity of S.tritici on main cultivars (mean % area leaf 2) |
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| Fungicide use |
| The ordinal position of the key timings remained constant. Overall each crop received on average 2.75 applications, more than any other year. Forty two per cent of crops received a three-spray programme with 70% of these receiving applications aimed at GS 31, 39 and 59. Ninety nine percent of applications of a strobilurin fungicide were applied with a partner DMI either as part of a commercial product or tank mixed. Fifty four percent of applications were made with the DMI product dose at greater than fifty per cent. |
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| Fig. 8 Fungicide use: per cent of treated crops receiving applications from the major fungicide groups post emergence. |
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| Fig. 9 Fungicide applications during the growing season. |
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| Sowing dates |
| Almost 45% of crops were drilled during September with 17% drilled before 20 September. Since the wet autumn of 2000, the average per cent of crops drilled during September is 45% compared to 27% of crops in the 1990s. |
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| Fig. 10 Sowing dates of survey crops (%) |
