Wet and cool weather has been hampering spring cropping plans for both our agronomists in recent weeks as thoughts turn to key fungicide timings on wheat. Dominic Kilburn writes.
For Nottinghamshire-based agronomist Christina Scarborough, this is the first season that she had to recommend a light leaf spot spray on oilseed rape crops in the region (metconazole was applied which also gave another chance for a PGR on the forward crops). “We’ve seen it here before but this is the first time we’ve had to spray, which we did in January, and it’s probably because it was such a mild winter,” she commented, speaking in mid-April.
While warm and wet weather prevailed for most of the winter months, a cool and wet period during the first half of April has meant that very little spring drilling has taken place in terms of sugar beet and spring barley, although by the time this magazine has hit the doormat Christina is hoping things will be in full swing.
The cool weather has also held back flea beetle in oilseed rape, she reported, and this has allowed crops to get past the vulnerable green/yellow bud stage and onto flowering.
“A sclerotinia spray is up next at full flower, just prior to petal fall, and I’ll be recommending applications of Amistar (azoxystrobin) as it has always worked very well on this disease.
“A one-spray programme should be sufficient this year as crops all seem to be forward and even in growth stage,” she added.
Christina suggested that, coming out of winter, cereal crops had “romped on” and were hungry for nutrition, especially winter barley which was hit with disease much earlier than the wheat. “Corbel (fenpropimorph) was applied at the end of March to mop up mildew, mainly, and some net blotch, and micronutrients were also applied to give the crop a lift,” said Christina.
“The first winter wheat fungicide is being planned for the latter part of April as I am now seeing septoria on the older leaves and so crops will get an application of Alto Elite (chlorothalonil + cyproconazole), or similar to prevent the disease being transferred to the newer leaves through rain splash.
“I’ll save the SDHI for a later treatment,” she commented
Black-grass remains a big problem in the area with Atlantis treatments being a bit “hit and miss” when applied at the start of February. “Autumn pre-ems worked well, especially for broad-leaved weed control, but big areas of black-grass remain and some areas of fields may have to be taken out,” said Christina.
The Basic Payment Scheme (BPS) is now at the forefront of her workload as the deadline (16th May) is fast approaching. She urged farmers to check last year’s payment statement and contact the RPA if there are unexplained penalties, as there seems to have been a ‘glitch’ in the system (tel: 0300 0200 301).
Christina can be contacted via email: [email protected] or tel: 07969507082.
AICC and Indigro agronomist Damian McAuley is based in Northamptonshire but also advises growers on land in Leicestershire and Lincolnshire.
Speaking in mid-April he said that it had been exceptionally wet and with soil temperatures low coming out of winter crops were in desperate need of some warmth. “Wheat is looking marginally better now in terms of colour but all crops have been reluctant to get going in the cool and wet conditions, even those that are more forward,” he pointed out.
The weather has also caused a frustrating stop/start to the spring drilling campaign with “some sugar beet wanting to emerge and some not yet drilled”.
“T0s are mostly done on wheat with only a few to go but I expect to be preparing for T1s on the early varieties by the time this is being read. However, disease is not as bad now as it was at the end of February when yellow rust and mildew were widespread.
“The cold weather has supressed those diseases, but septoria is prevalent in the bottom of crops and with rainfall being a key driver of septoria infection we will need robust sprays at T1 and T2, particularly with the catchy weather we are experiencing,” suggested Damian.
Oilseed rape development is very variable – some crops well into flower and some five weeks off – but he is hopeful that they will be more even in development by the start of May. “Because there is variability and flowering is likely to be protracted, it will likely mean a two-spray approach will be necessary for sclerotinia control,” he said.
Only a few fields have been badly affected by flea beetle larvae, notably those towards the Cambridgeshire side of his area, but elsewhere the picture doesn’t seem to have been a problem.
“Lower temperatures recently have kept insect numbers down, but pollen beetle are now easy to find in oilseed rape and aphids too are becoming evident on some spring cereal crops,” he added.
After some good yielding harvests and three warm and wet winters, Damian said that he would encourage growers not to skimp on fertiliser applications this season as low soil nitrogen reserves are being confirmed by some Deep N soil tests he has had conducted. Manganese deficiency has also showed up this year in cereals and oilseed rape.
“Some intense periods of rainfall during March may have reduced the efficiency of early nitrogen applications, but despite weather interruptions and some poor ground conditions the application of our main top dressings are nearly completed,” he said.
Damian can be contacted on email: [email protected]