12th April 2013: Yet another week of little growth but at least the drier conditions have allowed some field work. Oilseed rape crops are still being hammered by pigeons and concern mounts as these crops could be very susceptible to pollen beetle damage once the weather warms up. The most forward crops now have green buds appearing but as yet still no significant stem extension. The most forward winter wheat crops have barley moved and are still just moving towards GS 30. Disease levels remain low.
: Blackgrass needs controlling
: Watch out for pollen beetle
: No increase in Light Leaf Spot
: Disease levels in winter wheat and barley remain low
Pollen Beetle: Migration into crops starts when temperatures reach 15ºC which according to the Met Office forecast is unlikely to happen until the end of next week. Damage from pollen beetle could be more severe this year as crops struggle to develop after prolonged pigeon attack and cold weather. Crops are at their most vulnerable stage between the green and yellow bud stage. Threshold levels have been amended recently and are now based on plant population. The rationale to basing the threshold on plant population is that low plant population will produce more branches and therefore more flowers.
Pollen Beetle control thresholds:
- <30 plants/m2 ~ 25 pollen beetles/plant
- 30-50 plants/m2 ~ 18 pollen beetles/plant
- 50-70 plants/m2 ~ 11 pollen beetles/plant
- >70 plants/m2 ~ 7 pollen beetles/plant
Septoria on lower leaves of winter wheat (picture courtesy Farming Online).
South East: 10 days of largely dry weather have enabled some fieldwork to get underway again, but a continuation of easterly dominated winds have left soil temperatures stubbornly stuck at around 3-4ºC, and unsurprisingly there has been negligible crop growth again. Forecasts are suggesting that Spring may finally arrive next week, along with more rain! All later drilled crops are now desperate for some milder days and nights to encourage plenty of vegetative growth over the next 2-3 weeks ahead of stem extension. Most crops are still at around GS13-21 and appear to have hardly moved in the last 6-8 weeks, other than greening up slightly in response to applied N. However, these later drilled crops have visibly shrunk in the last 2 weeks in response to the latest blast of Winter, and are looking quite sad now.
Blackgrass: due to lack of residuals applied to most fields last autumn, many fields have a level of blackgrass evident ranging between GS13-21 in November sown wheats to GS23/24+ in September/early October sown crops.
Eastern Counties: Wheat crops have barely moved for nearly 3 weeks. The most forward are just about at GS 30.
Septoria tritici: trace levels on lower leaves.
Weed control: grass weeds now tillering where they haven't been controlled by autumn applications, this includes blackgrass, ryegrass, meadow grass and bromes.
East Midlands: While little in the way of development there has been definite greening up over the last 2-3 days and signs of new growth starting. Further N about to go on varying from 50-80 kg/ha depending on crop - more forward crops getting higher rate and backward crops getting a spilt with more in 7-10 days. Manganese deficiency being treated.
Septoria: on older leaves but not to high levels.
Weed control: warmer weather should give a chance to get some spraying done as blackgrass will grow just as rapidly as the wheat. Next week looks likely when showers have gone.
West Midlands: Early sown Humber, Grafton and Solstice all at end of tillering moving towards GS 30 on some main stems (tends to be lighter land crops). Most crops scorched and blue and later sown smaller crops look awful. Some late crops have given up mainly where they have had slug problems along with crows and rabbits. Ground conditions once again fantastic with many rolling the late sown, smaller crops at the end of last week and through into this, hopefully it will encourage better rooting and more tillers. Most have applied or are applying second dose of nitrogen.
Mildew: trace levels in base of crop on forward Humber.
Septoria tritici: very evident on the forward crops, whatever variety, none on new leaves.
Yellow Rust: trace levels found on crop of Gallant but others including Oakley remain free.
Fusarium/Eyespot: early symptoms on stem bases in some but not all crops.
Weed control: still not applied any spring herbicides due to continuing low temperatures.
Winter Oilseed Rape
Watch out for Pollen Beetle in backward crops (photo courtesy Farming Online).
South East: Pigeons still remain a real nuisance in around 50-70% of crops, with many fields now resembling stubble due to the skeletal remnants of rape - desperately need a milder spell to encourage some rapid new growth. Most advanced and ungrazed crops have flower buds extending now.
Light leaf spot: beginning to find some infection foci now in around 30% of crops that have been relatively ungrazed. Quartz and Agatha appear to be the worst affected varieties currently - however cold dry conditions are at least slowing down the infection cycle.
Phoma: no new infection.
Weed control: significant populations of cleavers and mayweed appearing but waiting for milder weather before applying herbicide.
Eastern Counties: The crops which were relatively forward and have managed to keep some canopy are now growing slowly into stem extension. The pigeon damage has been relentless with more damage still being done and foliage disappearing. The worse damage has left crops with just the central buds trying now to produce some growth, these are also showing some stem extension but there is barely a leaf to be seen. The cold and drying winds have caused a lot of leaf scorch especially in exposed sites. On closer inspection there also appears to have been some damage to flower buds. In terms of comparative growth between varieties PR46W21 looks the most vigorous and Cabernet the slowest. We have split nitrogen applications 3 ways on all farms not wanting to put too much on in one go when there has been so little growth, second applications are now on.
Phoma: Phoma spotting obvious but the majority of crops were treated in November and the lesions are old.
Light Leaf Spot: Still difficult to distinguish which lesions are light leaf spot - I don't believe I have seen a great deal in NW Norfolk as we continue to inspect crops. Looks now unlikely if we will use much growth regulator but may consider a spray more targeted against light leaf spot protection during stem extension - there is discussion amongst clients that we may now wait for early yellow bud as we are expecting the crop to romp through its growth stages as soon as it turns warm.
Pigeons: continue to be a real problem and need to be kept off crops at all costs.
Pollen beetle: we will have to keep a close inspection for beetle activity on warm settled days as some crops may well grow more. Like spring rape crops following the pigeon damage being especially susceptible to loss of buds due to beetle activity.
East Midlands: In spite of warmer weather pigeon hit crops show little sign of new growth although close examination show some attempt - general concern over the potential short length of flowering when it eventually gets going and plants flowering on short stems. Second split of nitrogen to go on with remainder of N to go on at yellow bud.
Phoma: with a lot of unsprayed crops I expect to see some Phoma in crops this year.
Light leaf spot: not a lot of leaf to get any yet.
Pigeons: continue to hit crops with reports of pigeons dying in fields through starvation!
Weed control: Herbicide awaiting to go on now weather warming up but how well it works on open crops with no crop competition to help control the cleavers is up for debate, some re-growth may occur. Period to spray may be short if warm weather causes rape to bolt and put out buds quickly.
West Midlands: No real change in growth stage, one crop of PR46W21 does appear to be moving, most crops though are stationary and crops being battered by pigeons as bad now as all winter. Some crops do have buds appearing but probably because the pigeons have eaten all the leaves surrounding the buds. There has been some frost damage to flower buds.
Phoma: still crops in need of treatment.
Light leaf spot: no obvious signs yet.
Pigeons: as bad as ever and needs constant attention particularly on the small crops.
Weed control: frosts have knocked back some of the larger charlock plants.
North East: Growth stage ranges from 3 leaf stage to Green Bud. Green bud visible on many forward plants. Backward crops shown little growth under cold weather.
Pigeons: a lot of damage to crops.
Phoma: no new lesions seen on new leaves.
Light leaf spot: no new signs of disease.
Weed control: larger Runch and Charlock have been checked by the recent frosts.
South East: most advanced crops are now at around GS24-29, no change to previous week.
Eastern Counties: crops at the three to four tiller stage with very little disease.
East Midlands: little or no change in growth stages. Disease levels remain low.
West Midlands: barley really is stationary at the moment, not a single crop approaching GS 30 yet. Traces of Net-blotch and Rhynchosporium. Frost has seen off any mildew that was trying to develop. Adding growth regulator to T1 sprays on most crops due to fear of lodging due to rapid growth if it ever happens.
North East: crops are mainly at GS 24/25. Crops are generally not as stressed as the wheat crops from the severe weather. Forward crops are pushing toward GS 30. Yellow Rust spores on odd forward lush crops but disease levels are low for the time of year.