Farming News - Light Leaf Spot damage in South

Light Leaf Spot damage in South

21 March 2014. Another dry week has helped get spring sowing underway. Potato planting has been carrying on at a pace too. Priority for many has been fertiliser application on all winter crops. Winter oilseed rape has grown dramatically and eratically on some fields. It's quite common to find plants at early stem extension through to yellow bud within the same field. The exception seems to be the semi-dwarf varieties which are reluctant to leave the comfort of mother earth. Winter wheat at its most precocious is now at first node detectable, fortunately these crops are rare. A return to colder conditions over the next week will put a halt to growth, diseases, pests and any fanciful notion of an early spring.

 

  • Light leaf spot damage to crops in South
  • Pollen beetle threat diminishes
  • T0 fungicides planned for forward crops of wheat
  • Blackgrass - outstanding herbicides need applying
  • Yellow rust at low levels in most regions
  • Brown rust in southern wheat
  • Net-blotch and Rhynchosporium at low levels
  • Wet winter has left soils in poor structure


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

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

 

Winter Oilseed Rape 


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Watch out for pollen beetle as temperatures rise.

South. All crops now range from  Green bud  (Quartz/Ovation/Vision) to Yellow bud (Alienor/Trinity) – many have retained a significant canopy this year, with GAI of >2 being common. 1st N+S Applications have now all been completed, with more backward/open crops having second N applications made now before crops get too tall. Quite a number of crops have opened up substantially and lost vigour as they have extended rapidly in recent warm weather, indicating that soil N supply is limited in many cases.
Pollen beetle: there are some about.
Phoma: only very low levels of renewed leaf spotting are evident in crops that were sprayed in November.
Light leaf spot: worst affected crops have had canopies badly affected by infection – triazole fungicides are definitely not as effective as they were against Light leaf spot and varietal resistance will become an important consideration in varietal choice for subsequent years.
Weed control: most Kerb was eventually applied between December and end of January but a few fields were missed out as just too wet.


Eastern Counties. Crops continue to move rapidly through stem extension in  a matter of days several have reached yellow bud and some of the earliest have flowers open. Most crops have only had one N application because of the speed of growth may put the remainder on as one rather than two applications (plus some liquid N on the pods where used). Some very spindly growth in late crops making them look short of N. Dry just 1-2mm of shower rain. Could do with some rainfall to wash N in. Growers are very busy catching up with general agronomy jobs, drilling and fertiliser application have generally been prioritised and some crops will, therefore, receive the metconazole or Caryx application on the late side. Canopies do not look quite as full and forward as they did earlier in the season. I think the dry weather has affected N uptake. Would like to apply the growth regulator products where possible to even up branching and flowering and they will give some early sclerotinia protection.
Light leaf spot: a little LLS appearing- not developing a great deal in current dry conditions.
Pollen beetle: relatively low numbers caught on traps so far.
Pigeons working away in corners of some crops and although grazing has not been widespread they continue to feed on these backward areas tucked out of view often.


East Midlands. Forward crops at green/yellow bud. Almost all crops have a GAI of 1 or above (a few with two) and will require a growth regulator. First N now on, split where forward, delayed (and reduced) where very forward and average crops have had about half total dose mainly to fit in with sulphur requirements and fertiliser blend.
Light leaf spot: levels remain low.
Pollen beetle: low levels only.
Weed control: it is now too late in many crops for further broad-leaved weed control.


West Midlands. The semi-dwarfs PX109 and Troy still being reluctant to stand up and are way behind most other varieties, some crops of Cubic, Avatar and Marathon are just starting to flower. Some of these crops are waist height already. Some are going to have to apply final split of N in the next 10 days to ensure even spread pattern.
Pollen beetle: rare even on sunny afternoons.
Club root: two cases now both on Troy.
Phytophthora: finding in more crops but it is in wet fields. Symptoms are purple stunted plants. In some cases the entire root system below ground has completely rotted away and plants can be easily pulled from the soil.
Light leaf spot: trace levels in some crops.
Weed control: Charlock and runch are the main issue and unfortunately it is now too late in most crops for control.


North East. Crops range from stem extension to yellow bud. There has been rapid growth in most crops and care is needed on fertiliser rates. Wide temperature fluctuations, with frosts in morning and warm midday. Average temp for week  8.4 degrees.
Pollen beetle: none seen.
Light Leaf Spot: increasing levels of  light leaf spot seen.
Weed control: now too late for post emergence herbicides.

 

Winter Wheat


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Yellow rust evident in crops

South. Wheats now responding to applied N+S, though were actually in need of rain to fully access applied N – 10mm overnight Thursday should do the trick. Growth stages are still generally late tillering to early stem extension, with the most advanced fields approaching true GS30 – primarily Gallant and Cordiale. All crops have had first N+S fertiliser applied and faster developing varieties (Cordiale, Gallant and Solstice) will get first main dose N (75-100 kg/ha) applied by the end of March.
Brown rust
: still only low levels detectable at present but likely to increase rapidly with current daytime temperatures hitting 15-17’C. T0 Triazole + Bravo mix scheduled for leaf 4 emergence – last week of March.
Yellow rust: only evident in fields/crops that did not have Galmano seed treatment (particularly Solstice, Gallant and Claire).
Mildew: no active pustules seen to date.
Septoria: most September/October sown crops are carrying very high levels of Septoria on older leaves.
Eyespot: stem based browning symptoms can be readily found in many crops.
Weed control: later sown crops that did not receive any autumn herbicides are now a priority. Bromes are more obvious on headlands.


Eastern Counties. The transition from “flat to the soil” wheat habit, into the early stem extension growth (ie. GS 30) generally coincides with the Blackthorn breaking into flower. Soils are showing marked colour differences perhaps more so on fields with variable soil types, remembering that just over a fortnight ago, we had another deluge that put the land back to field capacity.    In places there are clear drainage issues, in others a cumulative thing of modest levels of compaction that has progressively worsened with these excessive winter rains.
Yellow rust: upsurge in visible signs of yellow rust.
Brown rust: trace levels.
Mildew: trace levels.
Eyespot: beginning to become more apparent.
Septoria: obvious on lower leaves.
Weed control: Wild oats, Fools  Parsley and Groundsel all appearing.


East Midlands. Forward crops at GS 30 but most crops at GS 25-29 with later crops at 23-25. Fields drying well and most accessible for fieldwork although one or two wet spots causing wheelings. Many crops have now had first N either alone or with sulphur.
Yellow rust: low levels only.
Brown rust: none seen.
Septoria: remains on older leaves and will be a threat. Most  crops to have T0 generally triazole + chlorothalonil or a a few cases low rate strobilurin + triazole + chlorothalonil
Mildew: levels continue to remain low and cold nights helping to hold it back.
Eyespot: odd stems showing sharp eyespot but not a lot of lower stem based browning yet. Continue dry weather will help, although night fogs are making lower stems wet.
Weed control: any outstanding blackgrass sprays now on and continue to find odd plants in fields where sprayed indicating possible resistance. No major emergence of broad leaved weeds yet.


West Midlands. Very early sown wheat now predominantly at GS 31 with leaf four at least half to 3/4 out. Other September sown crops at GS 30 later sown still at mid to late tillering. Field conditions continue to improve but there are some very deep tramlines on most farms. Some river side fields still have lakes where crops should be. All have applied sulphur + N, will start going around again next week on the more backward crops with second split of straight N. Soil capping and compaction is common after the prolonged heavy rains of winter, but fields are still too soft to roll.
Yellow rust: treatable levels on early October sown Oakley, early sown Solstice and Viscount still clean.
Brown rust: none seen.
Septoria: all crops crops carrying high levels. T0 applications starting on very forward crops from Monday 24th dependent upon weather.
Mildew: pretty nonexistent at the moment with just light land Leeds showing mildew worth treating.
Eyespot: what looks like fusarium on stem bases seems fairly common, especially on heavy wet land.
Weed control: bromes are well tillered in early sown wheat crops, more manageable in crops sown in late September onwards, plough drill fields are clean.


North East. Most crops range between GS 23 -30 and forward crops are beginning to extend. There are some lush crops with many tillers.
Yellow rust: seen in Leeds, Santiago and Kielder - T0 planned.
Brown rust: found in Target - T0 planned.
Mildew: levels have declined.
Septoria: present in many crops.
Wheat bulb fly: dead-hearts in some crops.
Weed control: cleavers and knotgrass beginning to emerge.


Winter Barley.

South.   Crops now generally at GS24-29, with only the odd fertile field of Cassata at GS30. N+S been applied to all crops, with remainder being applied in two splits around end March and mid-April. Rhynchosporium levels increasing rapidly on older leaves in crops of Cassata and Glacier particularly.
Eastern.
Some are very thick up to GS 28+ and fairly consistent.
West Midlands
. GS 30 none more forward than this. Some still mid-tillering. Rhynchosporium and Net-blotch present at low levels. Brown rust on Volume.
East Midlands. Forward crops at GS 26-29 but generally at 24-26. Rhynchosporium and Net-blotch present at low levels.
North East.  Crops range from GS 24 to GS 29. Some crops are lush with many tillers. Low levels of mildew, Net-blotch and brown rust.


Sugar Beet

Drilling has continued apace with most growers at least having made a start. There is plenty of moisture at seed depth on the whole and seed has germinated well within 7 days of sowing.  Good, fine seedbeds have been harder to achieve on heavier soils which have set hard on top and are wet underneath , the lack of winter frosts has not helped– we may roll some areas. Some early ploughed land has greened up considerably with weed growth over the wet, mild winter and the advice would be to spray off with a glyphosate product before cultivating. Many weeds are large and would soon re-set.