Farming News - Fusarium risk mounts as T3s loom

Fusarium risk mounts as T3s loom

01 June 2012. Winter wheat crops have continued to move quickly over the last week with ear emergence obvious in many crops and start of flowering in the south. Oilseed rape crops finally finished flowering with the exceptional hot weather over last weekend. Septoria in winter wheat is still the main story with many reports of the disease on final leaf 3 and reports from the south west of final leaf 2 also infected. The delays in T1 fungicide applications due to the weather and prolonged cold wet period between final leaf 3 and flag leaf emergence have tested the best of products this year.

  • Fusarium risk remains high as unsettled weather returns.
  • T3 fungicide timing in winter wheat a priority.
  • Wheat beginning to flower in the south.
  • Time to put wheat blossom midge traps out.
  • Blackgrass rising above the crop.

 

Winter Wheat

 

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Fusarium ear blight.

South.  All crops now range between GS52-61, with many crops now showing ears that are beginning to flower. T3 applications now underway, timed for ears emerged to start of anthesis.
Brown rust: none found.
Mildew: levels increasing quite widely now in any susceptible varieties (Solstice and Claire in particular) with thick/lush canopies that did not have Talius added to T1 or T2 applications. However, most crops remain free of any re-infection to date. Conditions are currently ideal for mildew development.
Yellow rust: some leaf pustule stripes seen on final leaf 2 of Gallant where T1 applications were badly delayed, otherwise most crops remain free from visible infection.
Septoria: infections also now very evident at 30-50% levels on leaf 3 and around 10-15% on some of final leaf 2 in any crops of  earlier sown Gallant/Solstice and Xi19, where T1 applications were delayed by 7-10+ days or gap between T1 and T2 was between 21-28 days -  even where Aviator was used at T1 to try and enhance eradication. Despite recent dry conditions, pressure remains high due to current humidity and significant morning dews.
Eyespot: a lot of obvious eyespot lesions now appearing in many September/early October sown crops (particularly Cordiale, Gallant and Solstice) due to the highly favourable weather this year – some mid-September sown Gallant is beginning to lodge now due to severe penetrating eyespot.
Fusarium: with ears now emerging rapidly and FERA reports of high levels of Fusarium spp inoculums present on leaves, this will be a year to use high rates of both Septoria and Fusarium active triazoles at T3.
Weed control: all spring applications of Atlantis have now been completed – so far control of blackgrass is looking perhaps more comprehensive than some autumn applications have been.



Eastern Counties. This week has seen flag leaf fungicides going on in earnest, especially where the gap since the T1 spray was more than 3 to 4 weeks, in some cases a little more. 
Brown rust: now showing on untreated varieties.
Yellow rust: high levels in untreated patches of susceptible crops.
Mildew: the more backwards crops showing quite a lot of mildew.
Eyespot: showing on crops but is not really penetrating the leaf sheath.
Septoria: evident on leaf 3 on some crops.  
Take-all: starting to see symptoms in second wheats.
Weed control: areas in some fields where blackgrass, wild oats or brome are visible.

East Midlands. Ears emerging on all but later crops. Odd crops in last few days in heat showing drought stress (rolled flag leaves) on gravelly soil. More hot weather and no rain could be detrimental to some crops in spite of wet April.
Brown rust: none seen.
Yellow rust: starting to come back in on Oakley which is having robust T2.
Mildew: levels remain low but odd crops of Solstice have some on final leaf 3 and have received low rate of Talius with flag spray.
Septoria: plenty found on lower leaves – flag leaf clean so far but with some late T1s time will tell.
Eyespot: generally low levels but sharp eyespot on Crusoe where T1 delayed due to weather causing some concern.
Wheat Blossom Midge: midge watch now about to start as ears emerge but this looks like being a year of low numbers so risk should be low but second wheat/hotspots will need monitoring.
Weed control: blackgrass patches being noted and resistance to Atlantis looks to be spreading

West Midlands. Early sown Grafton and Humber with probably 90-100% ears fully out but no sign of any flowers as yet. Majority of remaining wheat flag leaf fully out/booting.
Brown rust: none seen.
Yellow rust: no new infections seen.
Mildew: traces developing in the bottom of some thicker crops.
Eyespot: sharp eyespot levels obvious in many crops.
Septoria: can find septoria in some crops as high as final leaf 3 others confined to final leaf four and below, as yet no real picture as to early/late sprayed T1 or 3 week/4 week interval between T1 and 2.
Aphids: very few aphids found..
Weed control: Ryegrass and bromes appearing in some fields now.

North East. Ears 50% emerged in some Grafton. All other crops are in boot.
Brown Rust: no new infection seen.
Yellow Rust: some new infection present in a few crops of Oakley as T2 was applied, but should be no more now.
Mildew:
no new infection seen.
Eyespot: higher than usual levels present in most crops, but so far not seen stem penetration.
Septoria: crops with moderately open canopies are generally clean to at least final leaf 3 or 4, but dense early sown crops have significant levels of infection.  Viscount and Grafton are among the worst with flag and leaf 2 clean, but some infection on final leaf 3 and severe on final leaf 4. T3 being planned now. If clean will apply a good rate of Tebuconazole, but if not will be either straight Proline 275 at 0.45 L or lower rate of Proline + Tebuconazole.
Aphids: reports in area of some crops already with serious infestations and have been treated.
Wheat Blossom Midge: pheromone traps in fields now, but no infestation been identified yet.
Weed control: driving round Holderness the situation looks worse every day as more blackgrass heads emerge above the wheat. Despite some very robust herbicide programmes this is the worst result for many years and will leave a legacy of problems for the future.

 

Winter Oilseed Rape 

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Seed Weevil beginning to enter crops.

South East. All crops now finished flowering in last 5-7 days following heat and breezy conditions. This year has seen an incredibly extended flowering period with many crops having been in flower for 6-7 weeks – however pod set is perhaps not as extensive as might be expected from this duration of flowering, with quite a number of blind sites reflecting periods of frost etc (worst affected varieties appear to be DK Camelot and DK Cabernet with 50% of blind sites on main racemes and some side branches).
Seed Weevil : low levels of adults seen in quite a few crops in the last week, particularly on headlands, but many crops have nearly finished flowering now so not rushing to spray.
Mealy aphids : colonies beginning to be noted around headlands in particular.
Sclerotinia: risk of any new infection now over as crops have finished flowering – is now a question of waiting to see if fungicide programmes have been effective in a very challenging and high risk season.

Eastern Counties. Crops rapidly went out of flower over the weekend, still some yellow fields of DK Cabernet.
Mealy aphids : in small clusters scattered in some crops.
Sclerotinia: one or two growers applying a third fungicide towards end of flowering for Sclerotinia back up and pod diseases (alternaria) Compass used.

 

East Midlands. Many crops at end of flowering going from looking like mid flowering to 80% petal fall in 3 days in the heat. Crops look very well and well podded up.
Light Leaf Spot: just odd pieces but nothing of concern.
Seed Weevil : numbers remain low.
Sclerotinia: no more sclerotinia sprays planned and watching for alternaria this has not been a problem for some years but this is a strange season so nothing will surprise me.

West Midlands. Crops that were bright yellow beginning of last week have now turned with probably 90% of the petals now having dropped over last weekend. Rightly or wrongly all crops were sprayed from Thursday through to Monday of this week with second sclerotinia spray.
Seed weevil: still only low levels seen.
Sclerotinia: no signs of sclerotinia yet.

North East. At long last some crops are coming to the end of flowering, but most look as if they will have flower for another 7 - 10 days yet.
Phoma: no further infections seen.
Sclerotinia: second Sclerotinia spray of 0.75 L Amistar being applied over last 7 days, following earlier Filan application.


Winter Barley.

South. Crops now ears emerged to flowering – no more inputs until the combine.
East. Ear emergence in many crops.
East Midlands. All crops now have awns emerged with forward crops at start of flowering.
West Midlands. Ears out on many crops and some starting to flower.
North East. Crops are in full flower. The fungicide programme has done an excellent job, and it is difficult to find any disease at all.

 

Sugar beet

At last in the recent warm weather many crops are growing away from the bird damage but as plants produce further leaf poor areas of fields become more apparent. Some poor areas are gappy  from bird grazing or soil pest damage other poor areas just lack vigour. Often this is where the soil has slumped in a few cases lime has been needed.

We are applying manganese to most crops with herbicides or as a separate treatment. Weed control is hopefully complete in some fields but not all, we are continuing with cleaver and volunteer potato control in particular. Fields will need to be inspected throughout most of June however before they meet across the row making it a very long, drawn out season. Tractor hoes are busy in the dry weather primarily for weed beet control but also some growers believe it might help to loosen some of the seed beds which have set like concrete.

Beet leaf miner has not proved to be a problem in our area (NW Norfolk) so far. Low levels of eggs can be found but it would seem that some are egg case or now empty and the leaf miners have been controlled by the seed treatments. We are beginning to find a few winged aphids in crops but not wingless ones yet.