27th February 2015: The cold and occasionally wet conditions over the past fortnight have not stimulated much growth in winter crops. Oilseed rape crops are now being hit by pigeons with some large flocks around. Light leaf spot is becoming more evident particularly in the south and east although it is being reported in all regions now. Cabbage stem flea beetle larvae numbers are very variable and more noticeable where there was poor control of adults in the autumn. Yellow and brown rust can still be found in crops of wheat in the south and eastern regions. The long range forecast for March suggest that cold or at least below average temperatures could continue until the end of the month. Spring is not here yet.
Yellow rust at trace levels in Northern Crops
South East: Crops range from GS 21 to early stem extension. Ground conditions are very wet again following around 30-40mm of rain in the last 7 days. Soil temperatures are currently around 5C and nitrogen applications on second wheats and backward/grazed crops underway from now onwards. Deep N soil results are showing lower levels of soil nitrogen available than in 2014 with many fields only having around 25-40 kg N/ha. Brown rust is very evident in September sown Crusoe in particular and mildew looks poised to come back as soon as temperatures rise. Septoria is obvious on lower leaves of all September and early October sown wheats. Blackgrass is generally only at low levels in most fields following autumn residuals.
Eastern Counties: Early to mid-September sown crops now at GS 30 but the vast majority of first and second wheats are at GS 25. Late drilled crops after roots are only just at GS 22. Brown rust is still hanging on in over thick parts of crops such as overlaps and Septoria is evident on lower leaves of all crops. Blackgrass control in the main hotspots has been reasonable from pre-ems. Ryegrass control is becoming more of a problem. On a more positive note cleavers are much less common so far this year.
East Midlands: Crops are looking a bit blue/grey and in need of some warmer soils. Forward crops at GS 24 and later ones at early tillering. There are odd patches of manganese and slug damage but on the whole most crops are OK. Canopy assessment shows Green Area Index of around 0.25 to 0.3 in many crops. Many will need early March nitrogen and even some late drilled first wheat to get tillers going. No sign of any disease apart from some older leaf Septoria.
West Midlands: Early sown crops are very well tillered but none at GS 30 yet. The recent run of frosts has meant that any yellow rust or mildew seen is now dead. Broad leaf weeds in some fields are completely absent and these same fields are also showing no signs of wild oats nor brome (all min tilled ) these tend to be fields sown end of September with potatoes in the rotation. In fields where continuous combinables and sown in the first two weeks of September there are some big wild oats, brome and cleavers. The majority of crops have good root structure ( ie pulling big root balls up). But field conditions are currently soggy with the occasional waterlogged. Light land guys have made a start on applying P&K (last week) but that’s about all. Manganese deficiency is a major issue this year with some areas in fields completely dead, mainly restricted to lighter/peaty ground and in the main min-tilled. Where manganese was applied in the last week of January there has been no response at all, whereas more recent applications seem to be having some effect. No nitrogen/sulphur applied as yet.
North East: Early sown crops are well tillered and still vegetative whilst late sown crops, many in an attempt to control blackgrass, are at early tillering stage. There are traces of Yellow Rust in susceptible varieties and mildew is present at low levels on crops of Leeds. Septoria is evident on older lower leaves. Good results on Blackgrass control from autumn residual stacks, but thin wheat populations in late drilled crops may create challenging situations.
Winter Oilseed Rape
Light Leaf Spot starting to show
South East: Following colder and frosty conditions since mid-January, crops have been somewhat compressed and are now at an even rosette stage – many crops still have a GAI of 1-1.5, however. N+S applications just getting underway on more backward and less fertile fields – many crops have gone “purple” even on free draining fields, which is mainly down to very low soil nitrogen levels. Light leaf spot: beginning to find leaf symptoms now in a range of varieties, including Campus, Trinity, Charger and even Amalie (LLS res. Rating 7), though generally confined to individual plants rather than actual foci. White leaf spot is noticeable in some crops where second fungicide delayed until late January.
Eastern Counties: Crop has continued to go ‘backward’ losing more leaf and colour in the cold weather. A lot of crops are very purple with green central leaves which are just starting to grow with the flower buds tucked inside. Plants have sturdy thick stems and good roots, they grew well in the autumn but the canopies have opened up considerably since and crops no longer look as if they will need an extra growth regulator. Crops on lighter soils which grew rapidly in the autumn have lost the most leaf. Pigeons are grazing away on some outer leaves but generally damage is not extensive. A few farms have started the first NS applications others are holding back because of the cold weather and poor traveling conditions on the heavier soils. Beginning to find Light Leaf Spot, incubating leaves in plastic bags at 15C has helped with diagnosis. Light Leaf Spot seems more apparent where foliage is denser. A lot of Cabbage Stem Fleas Beetle larvae damage to leaf petioles found in Norfolk and wondering if this has exacerbated leaf loss over-winter. Larvae in the crops in Essex are easy to find where control of adults was poor in the autumn.
East Midlands: Most crops look well but many thicker than I would like. Phoma on old leaves but new growth looks clean so far and no sign yet of Light Leaf Spot. However, frost, winter damage and slugs are leaving some blotchiness on leaves so incubating them to determine presence of disease. A few crops more backward where autumn/winter slug damage continued. Weed control is generally good.
West Midlands: Crops have opened up with the recent cold snap. There are some big crops around and some more forward crops are showing signs of early stem extension. Pigeon damage is worse than last spring with some fields completely grazed and others with no damage at all. However, even the bad fields should be alright as they were well established and plenty of plants before they were grazed. Frost has taken out about 50% of the charlock. Light Leaf Spot is very variable with some crops showing no signs whilst in others it is beginning to make itself evident.
North East: Crops are looking considerably better than last year but many have too high a GAI leading to some large crops. Light Leaf Spot beginning to develop with Quartz suffering more than most. Cabbage Stem Flea Beetle larva have only been found in one crop so far. First nitrogen planned on some crops for next week, with the sulphur. Lots of pigeons around.
Crops mainly disease free.
South East: Crops range from GS 21 to mid-tillering. Disease levels remain unchanged with Mildew at low levels in Cassia where crops are thick. Net-blotch and Rhynchosporium are also at low levels. N+S applications now underway when ground conditions are suitable.
Eastern Counties: Crops are still relatively disease free with only traces of Net-blotch and mildew. Rhynchosporium and Brown rust are pretty much absent. Blackgrass control has been quite successful in the majority of fields although barley is rarely grown on fields with a history of blackgrass.
West Midlands: Nothing too forward and no major disease issues as yet. Most crops with low levels of broad leaf weeds but some as wheat seem to have no weeds at all. There are some manganese issues but nowhere near as bad as the wheat. Some later sown crops are backward and could do with nitrogen now.
East Midlands: Crops are a bit pale but on the whole looking good with low levels of disease. All will need some early nitrogen.
North East: Most crops are at mid tillering. No nitrogen applied yet, and Manganese deficiency is showing on light land crops. Disease levels remain low with only traces of Net-blotch, mildew and Rhynchosporium restricted to thicker crops.