| Highlights from the 2002/2003 Winter Wheat survey |
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- Total foliar disease levels were lower than 2002, when levels were the highest
for ten years. Although higher than 2001, levels were below the 10-year mean.
- For the thirteenth consecutive year Septoria tritici was the most severe foliar disease.
After 2001 incidence was the second lowest since 1996.
- Eyespot severity was low, although higher than for the two preceding surveys, levels were only
a third of those in 2000.
- After the high in 2002 the incidence of BYDV and take-all were consistent with previous years.
- The incidence of fusarium ear blight was the highest since 1998.
- For the third successive year Claire was the most common cultivar accounting for 25% of the sample.
- Eyespot severity was lower in crops following grass, an effect seen in the majority of past surveys
- Forty-seven per cent of the crops surveyed were sown in October, with 29% sown before 11 October.
- Ninety eight per centof crops were treated with a fungicide, with 94% of treated crops receiving more
than a single spray.
- 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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| Severity of foliar disease |
| Septoria tritici was the only disease to exceed 0.2% mean 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 western regions.
The incidence of the disease did not fall below 80% crops in any region. Only S.tritici, powdery mildew and Septoria nodorum
were recorded in every region. Brown rust was recorded in samples from the midlands, east and south east
regions and yellow rust was not recorded. Tan spot was assessed in three samples but was not subsequently confirmed. |
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| Fig. 2 Regional incidence and severity of Septoria tritici |
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| Eyespot was more damaging than in 2002 as a higher proportion of stems
had moderate symptoms and a lower proportion of stems had only slight symptoms. However overall,
incidence of eyespot was lower than in 2002. |
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| Fig. 3 National incidence 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 west midlands region. Severe eyespot was only
recorded in samples from the east midlands, east and south east regions. |
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| Fig. 4 Regional incidence of eyespot |
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| Nationally recorded levels of fusarium ear blight symptoms were almost
double those of 2002 and only fifteen per cent below those of the highest year recorded (1998) since
records began in 1987. Incidence was highest in the East and East Midlands regions. |
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| Fig. 5 National incidence and severity of ear blight |
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| Fig. 6 Regional incidence of fusarium ear blight symptoms. |
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| Two cultivars, Claire and Consort, exceeded more than 10% of
the sample. Followed by Malacca, Hereward and Deben these five cultivars comprised 58% of the survey. Of the
ten most popular cultivars, the highest average level of S.tritici was recorded on Savannah with 9% of leaf 2
affected and the lowest levels were on Xi19 with 1.7%. |
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| Fig. 7 S.tritici on main cultivars (mean % area leaf 2) |
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| Fungicide Use |
| DMIs and strobilurin fungicides continue to be the most commonly used. The proportion of crops receiving morpholine fungicides and those receiving
MBC fungicides was similar to 2002. |
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| Fig. 9 Per cent of treated crops receiving foliar applications from the major fungicide groups post emergence. |
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| The ordinal position of the key timings remained constant. However the proportion
of crops receiving a spray aimed at GS 59 or more appears to be increasing compared with the other timings.
Overall each crop received on average 2.58 applications, slightly more than in 2002. |
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| Fig. 10 Fungicide applications during the growing season. |
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| Sowing dates |
| The majority of crops were sown during October, with 62% of these sown before 11 October. |
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| Fig. 11 Sowing dates of survey crops (%) |
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