Farming News - Gout fly invades southern crops
News
Gout fly invades southern crops
10 October 2014
Welcome rain for many has meant crops have put a spurt on this week. Winter wheat crops across the country range from yet to emerge through to two tillers. Aphids have been found on crops without a specific seed dressing. Gout fly have invaded some southern crops. Oilseed rape crops range from 1 leaf to full ground cover. Aphid numbers in crops are still very variable from none to 10% although more reports this week of winged aphids and colonies, raising the spectre of Turnip Yellow Virus developing.
- Aphids - more reports this week arriving in oilseed rape crops.
- Slug activity picking up in areas where plenty of rain.
- Phoma - just beginning to be found in some regions.
Winter Wheat
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Gout fly eggs on winter wheat seedlings |
South. No significant further drilling since last week due to onset of wet weather, however around 90% of first wheats have now been drilled, with the only remaining fields being after potatoes, veg and later maize - drilling of second wheats around 75% completed now. Earliest sown wheats at GS 12-21 – many fields on heavier soils are showing very uneven emergence due to areas where seedbeds were dry before rain. Soils have rapidly become wet following around 50mm of rain this week – hopefully conditions may settle down again next week.
Gout fly: gout fly eggs can readily be found in last few days on earlier sown wheat crops that are around 2-3 leaves. Some fields have 1 or more eggs on every plant. Likelihood is that adults have concentrated egg laying on most advanced cereal crops in locality.
Slugs: onset of wet weather has dramatically increased surface feeding activity this week on fields after oilseed rape in particular – pelleting of cobblier areas of fields on heavier/stonier soils underway as emerged plants are showing foliar shredding. However, in general damage appears to be a lot less widespread than feared, largely due to the quality of seedbeds produced.
Leatherjacket: some moderately high levels being found in lower lying fields after long-term grass.
Blackgrass: just starting to emerge now in earlier sown crops. Any delayed pre-em applications due to dry seedbeds now being applied as a matter of urgency. Problem fields having Crystal + DFF or Liberator + Defy at pre-/peri-emergence. Fields with difficult blackgrass having Avadex applied ASAP after drilling.
Eastern Counties. Crops range from recently sown through to 3 leaf stage. Most second wheat is now in the ground and germinating. 85% of wheat now in and drilling has gone on a pace in the last few days. Some super seedbeds achieved which is helping establishment. Some sharp showers in the week.
Slugs: no damage yet.
Gout fly: some eggs about but not huge numbers.
Aphids: some seen on early sowings but these crops have had Deter seed dressings. Absent in later sown crops.
Weed control: more Avadex used this year and some robust pre-ems seem to be keeping blackgrass at bay for now.
East Midlands. Early crops at 2-3 leaves but a lot of brown fields where crops drilled and yet to emerge due to dry, but recent rain will now get these moving. 35 mm of rain in last week has been welcome.
Slugs: generally seedbeds have been good so risk of slug damage more likely as crops emerge rather than seed hollowing.
Weed control: blackgrass emergence slow in stale seedbeds with dry conditions. Most pre-ems on before rain so moisture should have activated them.
West Midlands. Crops range from still not drilled to GS 22. Early sown Grafton now has two tillers. Second wheats sown 16 days ago now have 1 leaf. But emergence of later sown crops has slowed down as soil temperature begin their autumn drop. Somewhere in the region of 50mm of rain since last Saturday has certainly put a bit of a dampener on the job, with many fields needing a few dry days before they can take machinery, fortunately majority of fields are up to date with any applications.
Mildew: trace levels on early sown Grafton.
Aphids: easy to find on non Deter dressed crops as they emerge!
Slugs: beginning to find some seed hollowing on heavy ground.
Weed control: volunteer beans proving a headache as so few products available for autumn control.
North East. Crops range from emerging up to two leaf. Wet this week with total rainfall for of 24.1mm. About half that received further south!
Aphids: monitoring T-sum reached for early emerged crops but none seen yet.
Slugs: activity low after rape stubble but wet conditions now.
Weed control: pre-emergence herbicides seem to be working well on blackgrass. Few cleavers now emerging.
Winter Oilseed Rape
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Myzus persicae (Peach-potato aphid) vector of Turnip Yellow Virus. |
South. Crops range from 3 true leaf up to 6 leaves – 75% of crops are now around 4-5 true leaves. Crops have almost responded with relief to soils finally being wetted throughout the profile by recent rain and appear to have put out an extra leaf this week already!
Phoma: still none seen to date, even on volunteers in nearby rape stubbles – despite rains this week, would not anticipate seeing any leaf spots in most crops for another 7-14 days at least due to effects of the very dry September. Some crops may well get away with a single Autumn fungicide this year in early November targeting both Light Leaf Spot and Phoma.
Light Leaf Spot: none seen to date.
Flea beetle: shot holing of cotyledons/leaves still surprisingly hard to find to date despite low levels of activity starting to appear last week.
Aphids: low levels of Myzus persicae nymphs beginning to be found in some crops now on up to 10% of plants across the field, but many crops still appear free from any infestation to date. Where >10% plants being found with aphid nymphs on crops are due to be sprayed from next week with either Plenum, Biscaya or Teppeki.
Slugs: after earlier problems, most crops now appear to have grown away from further damage.
Turnip Sawfly: no further larvae being found now following Pyrethroid applications.
Weed control: significant flush of blackgrass in many fields where there is a history of the weed.
Eastern Counties. Crops have continued to grow and now at 6 leaf +. There is complete ground cover on higher seed rate fields. Few poor patches. More rain around 15mm has continued to help crops establish.
Phoma: just beginning to see phoma spotting on most crops. Expect to reach threshold levels in mid October in Norfolk when willtreat with Proline.
Light Leaf Spot: none seen so far.
Flea beetle: no longer an issue very little fresh shot holing and crops well past the vulnerable stage.
Slugs: crops now past the slug vulnerable stage.
Cabbage root fly: no further cabbage root fly damage.
Aphids: can still find just a few winged green aphids with progeny. Very low levels of aphids will treat with Plenum or Biscaya tank mixed with Phoma spray.
Volunteer control: Centurion Max recently applied working slowly on blackgrass symptoms showing up more quickly on medow grass.
East Midlands. Forward crops now at 7-8 leaf and soon will have full ground cover if growth continues. Later crops at 3-4 leaves.
Phoma: none seen yet.
Flea beetle: all crops now away with no problems.
Aphids: recent winds and rain may have slowed them down a bit, but expect to spray when readily found in crops.
Slugs: damage levels remain low with just a few isolated cases where late drilled and slow growth in dry conditions.
Weed control: Centurion Max looks to be working well but evident de waxing.
West Midlands. Growth stages varies from 2 true leaf (late sown or late germination due to dry seedbeds) up to 6-8 true leaves. Some farms with extremely thick lush crops, most farms have had very good establishment and will need a cold winter to check the current rapid growth.
Phoma:just starting to appear on the more forward earlier sown crops.
Flea beetle: no signs of further damage.
Aphids: curiously it is the crops in the north of the region which seem to have more aphids. South Shropshire and Herefordshire are just beginning to find them, but north Shropshire and Staffordshire more easily found.
Slugs: most crops now seem to be OK, even those that are late coming through, some thin patches on heavy land crops but not so thin they won't make a crop.
Weed control: Fathen coming through pre ems on light land.
North East. Crops establishing well across all fields. Growth ranges from 1 to 5 leaves.
Phoma: none seen.
Flea beetle: some low level activity. Yellow traps out.
Slugs: low levels of activity only.
Pigeons: beginning to flock.
Weed control: pre –emergence herbicides showing effective start so far.
Winter Barley.
South: Earliest sown winter barley crops now emerging to 1 leaf – still a few fields left to drill.
Eastern: Most crops are in and a lot emerging. Most forward crops at GS 11.
West Midlands. Some still to go in but vast majority at 3-4 leaf , some now with 1 tiller. Aphids evident in crops even before they reach first leaf.
East Midlands. Barley just emerging between GS 10-11.
North East: Drilling to GS12.