Farming News - Crop report - shows pest & disease threat
News
Crop report - shows pest & disease threat
16 April 2010. Winter rape crops beginning to flower but watch backward crops for pollen beetle. Leaf three just emerging in forward crops in South and East. Yellow rust on winter wheat found in Eastern counties but elsewhere rusts of any colour are still absent. Early appearance of chocolate spot in winter beans. Winter barley crops mainly clean but brown rust found in South East.
Pollen Beetle Control thresholds
Winter oilseed rape:
– 15 pollen beetles/plant in well grown crops that can compensate for damage by producing more and larger seeds in lower pods.
– 5 pollen beetles/plant in backward crops, e.g. ones that have suffered frost or pigeon damage.
Winter Oilseed Rape
South East. Green buds fully visible to Early flowering – ES Alienor still most advanced variety. Strongest crops had 50-75% dose of Folicur applied at late green bud for PGR effects and also to provide some early foliar protection against Sclerotinia. Crops generally looking reasonable, though some could really do with rain to wash in final doses of Nitrogen now. Any pigeon grazing now mostly ceased as crops extend.
Light leaf spot: only very low levels in evidence.
Sclerotinia: current forecast is for wet weather to arrive at end of next week ie. at around early flowering – plan to get most crops sprayed with Proline/Folicur + MBC mixes ahead of rain at yellow bud to first flowers.
South West. First flowers now open on most crops. Growth has been rapid and Rape is catching up to where we would normally expect at this time of the year. After 30 years working with this crop I am still amazed by its ability to assimilate nitrogen and produce a viable canopy from next to nothing.
Light Leaf Spot: new growth very clean.
Pollen beetle : exploded in some areas with the onset of warm weather and a few crops reached threshold. Recent cooler days have seen a reduction in activity and as crops flower risk diminishes.
Eastern Counties. Rape is galloping through its growth stages although it is very variable from site to site and colder temperatures this week have slowed progress down. Most advanced are about 10% in flower but changing daily- least advanced only 30 cm tall!
Second N applied- but few sites have had any rain since this application. Third application where planned will follow on very closely as rape grows and becomes too tall for some spreaders to work efficiently.
Light Leaf Spot: still at low levels not seen on new leaves during stem extension.
Pollen beetle : more pollen beetle on warmer , sunny days mainly worse on headlands. Threshold levels only reached on one or two very thin backward crops.
East Midlands. Crops generally at late green bud to early yellow bud with very few crops starting to flower. Some later crops just at early green bud. Final N will be delayed as late as possible in early flower as long a spreader can get a spread across the crop.
Light leaf spot: levels remain very low and no action needed.
Pollen beetle: numbers have rocketed over weekend into early this week. Several crops well above threshold with as many as 20-30 beetle on some crops. Mavrik or Hallmark main spray and in many cases is being mixed with growth regulators where these are going on.
Weed control : many fields have had Galera but a few fields showing very late flush of cleavers where they were clean 2 weeks ago – cleavers in these fields just emerging to 1 whorl, so if Galera is prevented due to weather shouldn't’t be a problem (hopefully). One or two fields will now be missed due to weather delays and oilseed rape buds now showing above canopy.
West Midlands. Many crops just starting to flower although backward crops still only at green bud stage. Final nitrogen being applied due to concerns of not being able to apply product accurately before long due to rapid growth of crop
Light leaf spot: not seeing at any significant level.
Phoma: unsprayed crops still have low levels.
Pollen beetle : more pollen beetle on warmer , sunny days but cold nights have prevented build up. Backward crops need monitoring.
North east. Crops growing very quickly now with growth stages in the range ‘buds proud’ to ‘yellow bud’. Most crops had 75kg N early with Sulphur, and a further 75 kg N has been applied. For most crops this will leave 60kg to be applied at ‘yellow bud’ to early flowering, which will be over the next 7-10 days.
Light Leaf Spot: despite higher temperatures still not seen any significant levels. 0.6 -0.75 L /Ha Folicur planned at ‘buds proud’ stage.
Weed control: patches of Mayweed seen on a few headlands.
Winter Wheat.
South East. A return to colder nights and cool drying winds has again slowed crop growth somewhat in last week. Growth stages now range from GS29 to early stem extension (ie. GS 30>31)), with September sown crops now mostly at GS 30>31. Leaf 4 now up to 2/3-fully emerged on September sown Solstice, Gallant and Einstein with tip of leaf 3 now just visible on more precocious crops – T0 fungicides being/been applied to September sown crops when leaf 4 is fully emerged on main shoots. October sown crops will now probably only need a 3-spray fungicide programme this year.
First BYDV symptoms seen last week on mid-September sown wheat that had seed treated with Deter/Secur, but not oversprayed until February.
Brown rust: none seen.
Yellow rust: none seen.
Mildew: no active pustules visible now and recent cold nights and dry cool days together with a lack of lush soft growth to date mean that mildew risk is currently extremely low.
Septoria: very evident on all older leaves – only top 3 leaves appear free from symptoms.
Eyespot : beginning to find stem lesions in September and early October sown crops of Xi19, Cordiale and Solstice, but current conditions are not really very favourable
Weed control : finally all outstanding Atlantis applications now been completed – some been been waiting to be sprayed since November! Rather pessimistic as to likely levels of control now though.
South West. Crops are now generally moving into stem extension. Growth over the last week has been rapid. Majority are at GS 30 with September sowings touching 31. Leaf 4 is now emerging. Majority of crops are in a very tight range of growth stage. Exceptions are very late sowings which are still stubbornly slow.
Brown rust: none seen.
Yellow rust: none seen .
Mildew: developing rapidly in early drilled Humber.
Septoria: still confined to lower leaves.
Eyespot: only really obvious in very early drillings.
Weed control : Atlantis applications now complete. Blackgrass is booting in missed areas.
Eastern Counties. Crops actively growing and majority at G.S. 2.6 with some approaching GS 30. Crops actively growing. Soils dry enough to perform most field operations. Daytime soil temperatures up to 12ËšC, night time temperatures 6ËšC. Main nitrogen application underway on forward crops at GS 30-31.
Brown rust: odd pustules on susceptible varieties; Duxford, Zebedee, Cordiale. Epoxiconazole applications on susceptible varieties where there is risk of delay with GS 30 fungicide applications.
Yellow rust: just in the last few days active Yellow Rust has been found in the more susceptible varieties including Oakley, Robigus, Viscount and Solstice.
Mildew: disease present on late drilled crops and on susceptible varieties, Solstice, Conqueror and Claire, but not active.
Septoria: apparent in most crops, in particular on early drilled and forward crops.
Weed control : wild oats now at GS. 1.2 - 2.4 where not controlled in the autumn. Some spring wild oats germinating.
East Midlands. Most crops GS 30-31 with final leaf 4 emerging. Check leaves emerging as crops at GS 30 have leaf 4 emerging.This puts T1 GS 32 about 10-12 days away depending on weather.
Brown rust: none seen.
Yellow rust: none seen. But at risk crops have had something at T0 of Cherokee or similar.
Mildew: gone in the frost.
Septoria: no change with plenty on older leaves – these are now sloughing off. Drying winds and cool nights appear to be keeping it in check.
Eyespot: levels of stem browning dropping with dry weather and windy conditions. Very little stem browning penetrating below outer older leaf sheath.
Weed control : Atlantis applied about 2-3 weeks ago working well with good control. However odd field with very large blackgrass may have poorer results – time will tell
West Midlands. Crops range from GS 31-GS21. Early sown Humber, Grafton, Battalion and Diego now at GS 31. Ground has dried up rapidly this week as a consequence of high winds. We could do with some rain to wash the fertiliser in.
Brown rust: none seen.
Yellow rust: none seen.
Mildew: traces on Humber.
Septoria: low levels on bottom leaves.
Eyespot: noticeable in early sown crops of Gallant and Humber.
Weed control: Brome control - Will apply Broadway Star after T0 or where no T0 being applied approximately week beginning. 5th April. Remember 7 day interval either side of chlormequat applications.
North east: most forward crops at GS 31, Duxford appears to be an early variety. Later sown or to north of region crops are fully tillered to GS 30. No rain at all for last 7days. Fields are drying out well now, and even the ‘tenderest’ ones are travelling now. At GS 30-31 applying 1.25LCCC + 0.2L Moddus with T0 fungicide.
Brown rust: none seen.
Yellow rust: none seen. However, will apply a T0 fungicide to all varieties with a resistance rating of 5 or less. This includes Oakley, Robigus, Duxford, Gallant, Glasgow and Viscount. The T0 will be 0.75 L Cherokee.
Mildew: gone in the frost.
Septoria: levels appear much lower now than they were a month ago as new clean growth now pre-dominates, but older leaves are carrying a reservoir of infection.
Eyespot: no obvious infections seen.
Weed control : Autumn applications of Atlantis have generally worked but not totally satisfactory in all fields. High infestations present in many fields despite robust pre-emergence treatments.
Winter Barley.
North East. Crops GS 31-32. Net-blotch is the most prevalent disease in most crops. Broad spectrum fungicide mix of Proline 275 @ 0.37L + Comet @ 0.4L.
Eastern counties. Crops in good condition and actively growing and range from GS 2.2-30 with majority at GS 30. First fungicide applications of prothioconazole+ fenpropimorph+ azoxystrobin ongoing and nearing completion on some forward crops.
West Midlands. Crops range from GS 31 - 32. Traces of Net-blotch and Rhynchosporium Bontima to be applied in next week.
East Midlands. Crops approaching GS 30. Some barley getting top up of early first N and final N will go on in about 10 days or so aiming for about 180 kg/N/ha. Very little disease present.
South West. Winter Barley now at GS 31 and generally green and healthy. Where being grown as a third cereal it still looks hungry despite nitrogen.
South East. Growth stages now range from GS 30-31 - T1 fungicides now being applied to faster developing varieties such as Boost. T0 Fungicides recently been applied in combination with first PGR to more backward crops. T1 Comet+Proline to be applied in next 2 weeks.
Sugar beet
Hope to finish drilling this week. Unfortunately the stop/ start drilling season has resulted in a few fields being drilled close to rain and these have capped during current drying conditions. The next few days will tell how well these will emerge. Some of the last batch of drilling has gone into dry soil at seed depth. We may consider rolling some of these problem fields. So several beet growers will be hoping for rain.
Most advanced beet fully expanded cotyledons / first true leaves just showing. The early drilled beet have emerged well and are currently receiving post –em herbicides. 2nd N applications can also be made to these fields.
Winter Beans: early appearance of chocolate spot on crops from East to West.
Linseed now emerging and being hit hard by flea beetle.