24 October 2013. It is as though the weather is stuck on repeat as it continuous to be mild and wet. Crops are growing well although mildew is beginning to creep into some crops of winter barley and wheat. However, nowhere is it serious enough to require treatment. Phoma still seems reluctant to develop and threshold levels for treatment still have not been met. There is a report from East Midlands of Bean Seed Fly damage to winter wheat.

• Phoma control planned
• Slug activity low but be vigilant after recent rain
• Large oilseed rape crops may need PGR
• Blackgrass emerging quickly
• Manganese deficiency showing on light land
• Mildew developing in some barley and wheat crops
• BYDV - use T Sum to predict risk

BYDV T sum
‘T sum’ system of accumulated day degrees above 3ºC can be used to predict best spray timings. Temperature accumulation should be started from: six weeks after sowing for imidacloprid-treated crops date of emergence for other crops one week after application for pyrethroid-treated crops.
1 Calculate ‘T sum’ by subtracting 3ºC from the daily mean temperature and adding the result to the running total.
2. If ‘T sum’ is 170 (second generation could be starting) – consider a tank-mix insecticide if treating the crop for another purpose.
3. If ‘T sum’ is 340 (significant spread imminent)

source HGCA.

Winter Oilseed Rape 

South. Crops now range from 3 true leaf to 6-8+ true leaves – around half of crops are now around 5+ true leaves. Mild conditions continue to favour rapid growth and around half of crops are likely to need a PGR Fungicide before the end of October.
Phoma: first lesions seen in last few days on Vision, but only around 2-3% and on older leaves. Crops with 5-6+ leaves may well escape significant canker damage due to size of leaf petioles and also what now looks to be a late infection season.
Slugs: good seedbeds and dry soils have minimised problems.
Aphids: no Myzus Persicae adults seen to date.
Turnip Sawfly: low levels of larvae now being found on undersides of leaves in crops that have not had a pyrethroid applied – damage looks very similar to slug grazing.
Weed control: moderate/high levels of blackgrass emerged/emerging in some crops, particularly after spring barley, indicating low dormancy in shed seed. Aramo (1lt/ha) been applied where required and timed to target blackgrass before tillering. Worst fields where Aramo has struggled previously, are getting Centurion Max applied when crop is at 4 leaves+ - control from earliest applications is looking very good so far (98%+). Kerb is planned to be sequenced later in November/December.

Eastern Counties. Crop continues to grow in recent warm weather, all crops are now well established generally right up to the field margins with a few issues related to rabbit or partridge grazing for example. The most forward crops are half way to knee high but most are an ideal size still sitting relatively close to the ground with some space between plants. More wet weather / has been variable a further 21mm here in Peterborough but more in NW Norfolk. Little opportunity to spray.
Phoma: just the odd spot of phoma around. Aim now is to use just one autumn fungicide spray. Phoma is developing relatively rate on crops which have decent sized canopies and are less at risk from developing stem cankers.
Flea beetle:activity more noticeable on earlier drilled crops, however large plants are growing away from the damage.
Slugs: very little slug activity although it has increased during recent wet weather, grazing can be seen on larger lower leaves in the canopy. Most crops are well-established and just a few later drilled crops with smaller plants need attention with a slug pellet application required.
Weed control: planning Astrokerb targeted at poppies on light soils, probably apply soon before canopy completely shades weeds.

East Midlands. Forward crops at 7-9 leaves with later drilled crops at 2-3 leaves. Earlier drilled crops after fallow are very forward and above front wheels of quad requiring a growth regulator as soon as conditions allow.
Phoma: levels remain very low with just a few plants showing yellow blotches which may be the beginning of phoma.
Slugs: a few backward crops showing some damage and will require a low rate of pellets
Weed control: Centurion Max has worked well on blackgrass where used and now need cooler conditions to allow Kerb to go on. Looks as though my rule of thumb of bonfire night will be about right assuming temperatures fall, otherwise Kerb will be delayed but not for long or else blackgrass gets rooted deeper.

West Midlands. All crops especially light land crops are growing extremely rapidly. There are some very forward crops about and may need an autumn PGR. In general crops looking well in complete contrast to last autumn.
Slugs: no new damage seen.
Leaf miner: in some crops but not at damaging levels.
Phoma: still not going wild and yet to find a field at 10% threshold.
Weed control: follow up graminicides for second flush of bromes and volunteer cereals going on.


North East. Crops continue to grow well and range up to 6 true leaves. Average temperature for the week: 12.5 degrees, Rain 20.7 mm for the week.
Slugs: a little activity.
Phoma: still none seen despite lush canopy.
Weed control : various weeds seen emerging, shepherds purse, few cranes bill, chickweed etc.

Click here to view the Rothamsted Phoma forecast

Winter Wheat

South. With ongoing warm and moist soils, crops are still emerging around 10 days after sowing - earliest sown crops (20th Sept) now at GS21-22. Heavier soil types are starting to get wet in places now.
Aphids: none seen yet, but can be readily found on volunteers in oilseed rape
Slugs: activity becoming more prevalent particularly in crops after winter oilseed rape and second wheats on heavier soils, following another 40mm of rain in last 7 days. . Now switching to methiocarb based pellets where re-treating is required.
Weed control: rains have thoroughly wetted seedbeds now which is activating the pre-emergence herbicides, but where blackgrass is emerged and already at two leaves, planning overspraying with Atlantis in next two weeks. There has been a significant flush of bromes on some headlands.

Eastern Counties. Rainfall last week and over the weekend has slowed progress with the sprayer and for some the drill.  Crops range from emerging to first tillers. The mild weather has meant that some fields have emerged within 8 days of sowing.
Aphids: above average numbers of aphids around. BYDV follow up sprays may be needed this year.
Slugs: there are a minority of fields after rape where slugs continue to graze the emerging wheat crop.
Weed control: where contact products were applied to wet foliage on a dull, misty day, with rainfall the following morning, control from these mixes has been poor. Herbicide uptake is obvious in some crops.

East Midlands. Crops at 1-3 leaves with many forward crops at 3 leaves. Crops after maize at 1 leaf. Top soils very wet to saturated depending on how many heavy showers they caught. No fieldwork possible.
Aphids: none seen.
Bean Seed Fly: report of damage to wheat seedlings - crops being eaten off at below ground level. INRA information states that Larva development lasts 3 weeks. It feeds on decomposing animal or plant matter upon which it can fully develop. However, it is also much attracted by germinating seeds and young plants, forming galleries in the cotyledons, the small stems and the young shoots before they emerge from the ground . When the plant is more developed, its tissue is too hard for it to be attacked and the susceptible period does not exceed 3 to 4 weeks. The larvae pupate in the ground at varying depths.
Slugs: still damage levels remain low.
Weed control: blackgrass - some latent effect from pre ems showing but not enough to hold the populations back too well. Hoping for good weather in early November to get on top of spraying

West Midlands. We had quite a lot of rain over the last week and any min tilled/ unrolled ground/heavy stuff probably will not travel until next week, assuming it doesn't rain in between time. Crops range from emerging to two tiller stage. Some wheat has been drilled after maize but very little maize has been cut yet as it is not ready. Manganese deficiency beginning to show up on light land.
Slugs: just some cloddy unrolled fields needing patching .
Aphids: can be found.
Mildew: becoming more obvious on quite a few crops of Grafton, Leeds and JB Diego..
Weed control: recent rains have helped activate pre-emergence herbicides. Bromes are more obvious this year on headlands.

North East. Crops range from emergence to GS 21. All first wheats are  in now. Fields are wet after recent rains and conditions are too wet to travel on some days.
Aphids: few winged aphids sighted.
Slugs: no grazing seen so far.
Weed control: cleavers beginning to emerge. Blackgrass, bromes and ryegrass beginning to emerge.

Winter Barley.

South. Earliest sown crops now at GS13-21.
Eastern Counties. Most crops now in but later sown crops have patchy emergence due to dry seed beds. Main varieties are Cassia and Glacier with a bit of Volume.
West Midlands. Most forward crops at 3 leaf stage. Light land crops have low levels of mildew. Manganese deficiency showing up on light land.
East Midlands. Crops at 2-3 leaves and look well. Some small manganese areas which will be sprayed when weather allows with bittersaltz and cypermethrin.
North East. Earliest sown now at first tiller stage. Powdery mildew seen on Glazier.