: 25 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: '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|
Winter Oilseed Rape
Large crops may need autumn PGR (photo courtesy of Farming Online).
South East: 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.
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 although variable, a further 21mm in Peterborough but more in North West 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 late 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.
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: contact graminicides on blackgrass where needed.
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.
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.
Early sown wheat emerging well (photo courtesy Farming Online).
South East: 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.
Weed control: rains have thoroughly wetted seedbeds now which is activating the pre-emergence herbicides, but where blackgrass is emerged and already at 2 leaves, planning overspraying in next 2 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 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 this week.
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.
Aphids: none seen.
Slugs: damage levels still remain low.
Weed control: blackgrass - some latent effect from pre emergents 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 minimum tilled/ unrolled ground/heavy stuff probably will not travel until next week, assuming it doesn't rain inbetween. 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.
South East: Earliest sown crops now at GS 13-21.
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.
North East: Earliest sown now at first tiller stage. Powdery mildew seen on Glazier.