22 Aug 07: For the first 60 wheat grain samples analysed as part of the CropMonitor project the average deoxynivalenol (DON) content was 229 parts per billion (ppb). This is very similar to five year average (2002-2006) of 217 ppb. No samples were above 1250 ppb DON. Based on these results it is expected that only a low percentage of the 2007 wheat harvest will exceed 1250 ppb DON (the limit for wheat intended for human consumption).  

updated 17 Aug 07: Results from the national winter wheat survey show that over 90% of crop samples taken from across England had symptoms of fusarium head blight (FHB). The majority of ears were infected with Microdochium species, which do not produce mycotoxins, indicating that overall risks of mycotoxin contamination will be low. However, 30% of samples also contained Fusarium graminearum, which can produce mycotoxins under certain circumstances. There are some regional differences, with the East Midlands and South West of England having higher levels of F. graminearum than other parts of the country. Farmers are warned that lodging can increase mycotoxin risk and, of course, harvesting should be carried out as soon as possible.  

Early season reports from the CropMonitor trials highlighted unusually high levels of Microdochium spp. at the stem base. Results are now becoming available from the trials, indicating that incidence of head blight symptoms is high and that Microdochium species (non-toxin producers) are primarily responsible.  

Half of the 300 samples from the national winter wheat survey have now been assessed. Over 90% of these samples show symptoms of FHB, caused predominantly by Microdochium species (non-toxin producers) and Fusarium poae. Isolation of F. culmorum and F. graminearum (deoxynivalenol (DON) producers) has been much less frequent and, where present, levels have been low (<1% ears affected). Therefore, DON contamination of grain this year is likely to be low. Toxin levels may be raised if crops are lodged or harvest is delayed (See HGCA Guidelines).  

Brown rust is still a problem in many crops. In the CropMonitor trials, brown rust has been recorded on the flag leaf of all varieties (Einstein, Ambrosia, Solstice, Robigus) at Terrington, Louth, Boxworth, Andover and Morley. Several varieties are also affected at York and Rosemaund.   Click for further images .

IRAG have issued an alert indicating that the Peach-potato aphid (Myzus persicae) are being caught in unprecedented numbers this year. Weather conditions which have favoured aphid development together with a high level of resistant forms (MACE and knock-down resistance (kdr)), means that growers should be careful in their selection of insecticides. Where M. persicae is the dominant aphid, products based on chemistry alternative to pirimicarb or pyrethroids should be selected.   Click for further images .

Sclerotinia has been noted in crops in most regions, with levels of about 10% infection in some South East crops.   Click for further images .

With levels of Brown rust continuing to increase in the eastern half of England, the risk of further development is still high. Few if any varieties have shown adequate resistance such that this threat can be ignored.   Click for further images .

Recent wet weather has been ideal for the spread of septoria, and the risk of further significant disease development is therefore high in crops where the disease has progressed up the canopy. However, in situations where only low levels are present even on leaf 5, the overall threat from septoria this season remains moderate-low.  

The septoria risk is generally moderate-low, but with some indications that this is becoming highest in the south-west and lowest in the north-east. However, further rainfall predicted for next week combined with high temperatures and relatively short crops will increase the threat to the top three leaf layers, which are critical for yield.  

The increasing levels of brown rust that are being reported in fungicide treated crops (notably Alchemy) on farm are giving considerable cause for concern. If conditions remain favourable, susceptible varieties in the east of England will be at very high risk, and it is essential to maintain robust control and protection at the 'T3' fungicide timing. Even in areas where the disease has yet to become a serious problem, the risk in susceptible varieties should be considered moderate-high.   Click for further images .

Orange wheat blossom midge will start to pupate after a period of rain (for many this was 13 May), hatching in two to three weeks. There is a significant build-up of larvae in many soils, so rain now leading to hatching of the pest has the potential to cause serious damage. Earliest emergence is expected around 24 - 27 May.  

Brown rust still active, but recent weather conditions have led to slower progress than might have been anticipated. However the risk remains moderate to high in many varieties. Results from UKCPVS suggest that a new race may be present in the UK.   Click for further images .

A sustained period of wet weather has increased the risk of septoria in all areas. The ease with which septoria spreads from lower to upper leaf layers during rainsplash is partly dependent on how close the leaves are. Shorter crops, as are common this year, can therefore be more at risk.  

Stem-base isolations from plants at the CropMonitor trial sites are showing very high incidence of Microdochium species. This suggests Fusarium species will be developing in crop debris, thus increasing the risk of Fusarium head blight later in the season. No action is currently required, but this threat should be considered when planning T3.  

Brown rust is becoming more widespread, and has been noted in Alchemy, Claire, Consort, Robigus and Solstice in the South and East.   Click for further images .

National reports indicate mealy aphids (also known and cabbage aphids or mealy cabbage aphids) are present in oilseed rape in the South East, South West and East Midlands. In the SE and SW numbers are unusually high for this early in the season. The threshold is 13% of plants affected.   Click for further images .

National reports highlight yellow rust in Robigus in Eastern counties. This is confirmed by CropMonitor, which has recorded yellow rust in Robigus at Boxworth, Terrington and Louth. Yellow rust has now also been recorded in Robigus at the Cirencester CropMonitor trial.
The latest report from the NIAB Rust Trap Nurseries 2007 is now available. Click here for NIAB Rust Trap Nurseries.   Click for further images .

A new tool is now available to monitor untreated disease progress in this seasons CropMonitor trials compared to previous years.  

HGCA warn growers to be vigilant for brown rust.  

Monitor crops for Cabbage Seed Weevil. Thresholds are 2 per plant unless the site has a history of Brassica Pod Midge problems - in this case the threshold drops to 1 per plant. If the temperature in the crop is between 11 and 15 deg Celcius, multiply the mean plant count by 2.26 before considering the threshold. Information from the Oilseed Rape Manager encyclopaedia.     National survey results   Click for further images .

Brown rust has been reported at high levels in some varieties. All four varieties in the live monitoring trials in Boxworth and Terrington are affected, including Robigus which has a resistance rating of 9. National reports confirm that the problem is more widespread in the Eastern Counties. HGCA also warn growers to be vigilant for brown rust.   Click for further images .

Brown rust has been reported at high levels in some varieties. All four varieties in the live monitoring trials in Boxworth and Terrington are affected, including Robigus which has a resistance rating of 9. National reports confirm that the problem is more widespread in the Eastern Counties.   Click for further images .

Visible disease progress in live-monitoring trials is similar to the most advanced of the previous three years (2005), but current dry weather will be helping to reduce early infection of recently emerging leaves.  

Cabbage seed weevil found in South West. The best time to control this pest is during flowering when the adults arrive in the crop, but before they lay their eggs. For information from the Oilseed Rape Manager encyclopaedia click here.   Click for further images .

Recent mild days and cool, damp nights have been very favourable for the disease. Smptoms have for several weeks now been reported widely in untreated Robigus crops on farm in a number of areas. Therefore the current risk is considered to be relatively high.   Click for further images .

Trace levels of yellow rust are now present in some crops of Robigus.   Click for further images .

Brown rust is present at low severity in many crops. This disease is easily confused with yellow rust at this time. Check for yellowish halos around the pustules-these are typical of brown rust.   Click for further images .

Some at GS32, final leaf 3 emerging. This is nearly 3 weeks sooner than seen in the earliest drilled crops in 2006.  

Check crops for pollen beetle if at green/yellow bud, the treatment threshold is 15 per plant (or 5 per plant for thin or backward crops). The first beetles have been reported in the SW.   Click for further images .

Most crops now at or around GS 30, with some early sown crops at GS 31. Eventual leaf 3 just emerging in forward Einstein and Robigus in the South East.  

Yellow rust traces have been noted in some crops of Robigus   Click for further images .

Check crops for pollen beetle, the treatment threshold is 15 per plant (or 5 per plant for thin or backward crops). The first beetles have been reported in the SW, although there is currently little sign of feeding on green/ yellow buds.   Click for further images .

Light leaf spot has been seen in some winter oilseed rape crops. Low levels seen in the East (in several fields of Castille in Norfolk), and some new infection also seen in the North East.   Click for further images .

Aphids are present in wheat and barley crops treated in early autumn. Check crops for aphids.   Click for further images .

Moderate levels of Gout Fly are reported in crops sown before the end of September in the North East   Click for further images .

Stem browning is now evident in some crops, particularly early sown crops. In the East Midlands, this is considerable on crops of cordiale   Click for further images .

Wheat bulb fly levels are low so far   Click for further images .

Gout fly has been noted in wheat crops sown before the end of September in the North East and South East. In South East, very high levels noted in a few locations, primarily in sheltered fields and in blocks of continuous wheat.   Click for further images .

Results of autumn/winter assessment of commercially grown winter oilseed rape now available.  

In East Midlands (Soat/Trent valley) the most forward wheat crops are at GS 31. In other regions most forward crops are at or approaching GS 30  

Brown rust is now at low levels in most regions. Affected varieties are Alchemy, Claire, Solstice, Cordiale and Einstein.   Click for further images .

Crops are forward for the time of year, with some winter wheat crops now at GS 30.  

Brown rust has been found in most regions, although at trace/low levels. Cultivars reported as affected are Alchemy (in SE, SW, E Midlands and East), Claire (in SE), Solstice (in SE) and Einstein (in E Midlands).   Click for further images .

Agronomists comment on the effect of mild autumn on growth and implications for managment of crops in the spring  

Some treated crops in SE, SW, E and NE are showing re-infection with Phoma (threshold = 10-20% plants affected). Crops not previously treated at high risk.   Click for further images .

Yellow rust has been found at very low levels in a crop of Alchemy and in Robigus in Lincolnshire.  

Cabbage Stem Flea Beetle larvae being found in some rape crops in the South East and Eastern Counties. About 40-50% of crops in SE at economic threshold of 2-3 larvae per plant. Check stems for larvae.  

Cabbage root fly and Turnip root fly appear more widespread in the South West this autumn.  

Now at threshold levels in South, East, North East and East Midlands. West Midlands crops still relatively free, but now being found in Castille. Threshold: 10-20% plants affected (10% for small plants)  

Low levels of club root are evident in some areas of fields where brassica vegetable crops have been intensively grown previously. Watch for stunted plants or thin areas.  

More reports of Frit fly damage in wheat crops following winter oats, some fields in West Midlands have extensive damage   Click for further images .

Turnip sawfly damage seen from South East Coast to West Midlands  

Turnip sawfly damage in South East and South West. Some damage also found in Norfolk.  

Phoma is widespread in crops of winter oilseed rape in Norfolk, but not at threshold levels yet. Phoma is active and at threshold level is some crops in the North East. Threshold = 10-20% plants affected (10% for small plants)   Click for further images .

This summers weather has provided ideal conditions for Frit fly development. Dows PestWatch reports that Frit fly activity has been slightly higher and more prolonged than last year.   Click for further images .

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