Farming News - T1 for wheat but BYDV becomes more evident

T1 for wheat but BYDV becomes more evident

24 April 2016. The mid week spring sunshine and settled conditions allowed many to catch up on field operations. T0 fungicides in winter wheat are now mainly complete with T1 application underway on forward crops. BYDV in winter cereals is showing up in many crops and is taking the shine off potentially useful crops. Flag leaf showing in forward crops of winter barley in the eastern counties. Oilseed rape crops now mainly flowering although the forecast return of low temperatures will lead to a very protracted flowering period.


Winter Wheat

  • yellow rust declining after T0
  • BYDV becoming very evident.
  • Final leaf 2 starting to appear in forward wheat.
  • T1 applications started
  • Blackgrass heading


Winter Oilseed Rape

  • First flowers in all regions
  • pollen beetle numbers building in backward crops.
  • Light leaf spot


Winter Barley

  • Diseases levels remain low.
  • Flag leaf on forward crops.


Winter Wheat


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Yellow rust resurgence

South. Crops range from GS 30 to early GS32 – most crops sown before mid-November now have leaf 3 just emerging, with September sown Trinity & Reflection having leaf 3 75%+ emerged, and  Skyfall & Crusoe are generally  at leaf 3 at 10-50%  emerged. Cooler conditions with some frosts have again tempered growth & now sustained colder conditions are set to return once again. T0 Fungicides targeting Leaf 4 50%+ emerged all been applied & some T1’s have recently been applied to more forward crops in last few days, only 14 days after T0 – a reminder that there will only be 2-3 week spray intervals between T0/T1 & T2 this year. Most fields are traveling ok as we have fortunately missed most showers again this week, though 15mm of rain last Friday was not helpful.
Brown Rust:
recent colder conditions have slowed any progression to new leaf. Triazole or Strob with T0 applications in first 10 days of April.
Yellow Rust: some localised foci can be found again, even in Cordiale – current cool and damp conditions are ideal for disease development. T0 Tebuconazole or Strob.
Mildew: combination of low N status of most soils now and cold conditions has prevented any resurgence to date.
Septoria:
very obvious on older leaves of all September and early October sown wheats –  cool conditions of last 3-4 weeks have certainly helped in reducing visible inoculum levels on newer growth.
Eyespot:
stem based browning can be readily found in  earliest sown wheats, along with second wheat and wheat after oats.
Aphids:
BYDV symptoms beginning to show up quite widely now as crops respond to N in some late September/early October sown wheats not oversprayed with Cypermethrin until February. Surprisingly high levels also evident in some fields in sheltered coastal locations that were sprayed in early December following Deter seed treatment indicating significant virus transmission in November. Looks like being worst year for BYDV since 2012 in the South, as can even be found in Deter dressed late October sown wheat.
Weed control: blackgrass control to date is looking reasonable, with 75-90% of plants now showing shoot yellowing.

 

Eastern Counties. Earliest drilled crops have leaf 3 emerged (Gallant), most have leaf 3 half out, last drilled crops have leaf 3 only just showing. Wet and cold slowing growth.
Brown Rust:
trace levels only. T0 imminent.
Yellow Rust:
T0 keeping this disease in check so far.
Mildew:
none seen.
Septoria:
low levels on all varieties but some bad hot spots in thicker crops.
Aphids: None found but patches of BYDV now showing up in crops from winter infection.
Weed control: Blackgrass evident in all usual hotspots and now heading. Some of the worst areas are horrendous and will be destroyed. Very little over wintered weeds where robust pre-ems used. Little sign yet of spring germinators except some charlock.


East Midlands. Many crops at late GS 30 early GS 31. A very stop start week with frequent showers and few completely dry days. Wet patches in lower lying part of fields remain, however most crops look well and next N will be going on in about a week or so. Manganese deficiency showing in a few crops.
Brown rust: none seen.
Yellow Rust: still very apparent and seen on variety Leeds yesterday but tending to be on older leaves rather than new growth easily also found on Reflection, KWS Lili, Cordiale, Kielder which need T0 azole mix to damped it down.
Mildew: remains low even in such varieties as Leeds
Septoria: Plenty on lower older leaves but new growth so far clean but time is now pressing and a lot of crops yet to get the T0 due to the weather.
Eyespot: generally low but some stem based browning seen.
Aphids: none seen.
Weed control: time now will tell on blackgrass control. Atlantis /Pacifica activity now showing and looking better control than I expected with the late spraying. Some plants disfigured rather than dying so may find stunted plants in crops but hopefully reduced seed heads.


West Midlands. Majority of wheat has leaf 3 emerging to 50% out, with only the latest sown or most stressed from the wet with leaf 4 ¾ out. Quite a lot of crops at very variable growth stages within the same field which is making things a bit awkward but just having to compromise on timings to a certain extent. Majority of T1 applications will be from Monday 25th through to the end of next week with perhaps 20% of area going on week beginning 2nd May.
Brown Rust: still there at much reduced levels.
Yellow Rust: very much in the decline thank goodness.
Mildew: now virtually non existent.
Septoria: waiting for this to explode after recent heavy rains..
Aphids:
BYDV patches becoming more evident in many crops now.
Weed control: very few spring germinating weed so far.


North East. Crops range from GS 30 to final leaf 2 just starting to appear. Recent dry settled spell has helped catchup and many spray jobs done in the last few days.
Yellow Rust : developing on variety Horatio.
Brown Rust:
none seen.
Mildew:
low levels in variety Leeds.
Septoria:
increase with wet weather. Very robust T1 planned
Weed control: blackgrass begriming to extend. More spring germinators seen, charlock, hemp nettle, wild oats


Winter Oilseed Rape 


Pollen Beetle. Migration into crops starts when temperatures reach 12 - 15 0C.

Plant populationThreshold level of beetles per plant
25
30 - 50 plants/m2
18
50 - 70 plants/m2
11
>70 plants/m2
7

 

 

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Crops at early flowering

South. With a continuation of  generally cool days and occasional frosty nights, growth remains  relatively slow, though apart from a few backward fields crops are finally beginning to grow away from  pigeons. Crops range from late green bud (Amalie & pigeon grazed) to 30%  flowers visible (Campus & Ovation).
Light Leaf Spot: - conditions remain very favourable for renewed infection meaning that early flowering sprays will need to have good Light leaf spot activity.
Phoma: no recent sightings.
Club root: severe symptoms found in only two fields so far.
Pollen beetle: found now quite readily in open flowers and some on green buds, but not at threshold levels yet. With weather looking to remain cool, backward and pigeon grazed crops could remain vulnerable to attack for another 2 weeks.


Eastern Counties. Many varied growth stages in fields. Some are now at approx mid flowers with first pods set, some are still only just showing signs of flowering in parts of the field. Mainly linked to wet, pest damage and weed burden.
Light Leaf Spot: Variable levels across different fields and varieties. Not bad but usually able to find a background level. Varieties with poor resistance ratings will get a flowering spray that has activity for LLS.
Aphids: none seen.
Pigeons: really hitting crops hard still. Some severe grazing.


East Midlands. Most crops now starting to flower with later crops at yellow bud where pigeon damage has slowed them down. Final N being held back to manipulate canopy but will be going on soon before crops get too advanced to allow a good spread of fertiliser.
Light Leaf Spot: finally all sprays on, especially the at risk crops.
Pollen beetle: numbers generally low but with the odd field showing higher numbers but in flowering crops so no concern apart from the much later pigeon damaged crops.
Aphids: none seen.

 


West Midlands. Most crops are flowering helped by the warm spell in the middle of the week but still cold at night. Sitting tight on sclerotinia applications until such time as nights warm up (need + 24hrs with temps over 8 deg C (optimum 10 deg C ).
Light Leaf Spot: most crops now treated.
Pollen Beetle:
low levels especially in backward areas of crops.
Flea beetle :
none seen.

 

North East. Green/yellow bud but majority of crops now at early flowering. Some crops are looking short where soils have been wet.
Pollen beetle : low levels.
Light Leaf Spot: Still present in some crops
Phoma:
trace levels.
Pigeons: have been more problematic than last year, stripping leaf from many crops.

 

Winter Barley.


South. More forward crops now at around GS31-32 & more backward fields around GSS30-31 – all earlier crops have had  T1 fungicides applied this week & rest will be next week. Only low levels of net-blotch, Rhynchosporium and mildew found.
Eastern. GS 32 common. Furthest forwards have flag leaf emerged. BYDV patches evident even where cypermethrin used. Remain short. Very low disease levels. T1 fungicide now done. T2 aimed at awns emerging or three week interval.
West Midlands. Crops all but sprayed, some discussions now going on whether we will need a T2 due to lateness of T1 Siltra applications even where crops have only just had the Siltra they are remarkably clean . BYDV patches are starting to stand out more and more.
East Midlands. Many crops at GS 31/32 and look well. Disease levels remain low so far with clean new growth.
North East. Crops mainly at GS 32. No T0’s applied due to weather and other commitments Disease levels remain low with the exception of Mildew on Saffron.

 

Spring Barley

South. 90% fields are drilled and range from just sown to 3 leaves. Remaining fields will hopefully get sown next week
Eastern. First drillings now tillering well. Drilling generally finished. Emergence generally good and frequent showers preventing bad capping. Cold weather doesn’t seem to be slowing barley too much.
West Midlands. Majority of spring barley should all be in by the end of this week with the earliest crops at 2-3 true leaves. Some herbicide damage seen.
East Midlands. All drilled and some just starting to show.
North East.  All crops now in with earliest now at full emergence. Field conditions still wet.