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CHALLENGING YEAR AHEAD FOR UK GROWERS
Date added: 10/02/05 |
Optimum use of fungicides, controlling Brome and dealing with the growing problem of Orange Blossom Midge will be the biggest agronomic challenges facing UK crop producers in 2005, says ProCam technical Director Dr. David Ellerton.
Last year saw an increased threat from many diseases, pests and weeds due to the warm wet conditions and this legacy will cause problems for growers throughout the UK this year, he warns.
“Last year we had the highest levels of Brome ever recorded and it was also the worst for Orange Blossom Midge, for a many years. Disease levels were high as well and all told this means there is a strong latent threat that has built up for this season.”
The main issues surrounding disease threat will probably come from Septoria and stem-based diseases, with issues complicated by growing product resistance and potentially low grain prices making some treatments border-line.
With Brome, the number of different species and the need for different control measures for each combined with the huge impact on yield from not addressing the problem early enough will be the main challenges facing growers, Dr. Ellerton says.
Early identification of the potential scale of the Orange Blossom Midge is also
essential as last year it is estimated some 6% of the total wheat crop was lost, almost unseen.
Dr Ellerton’s pointers for effective management of these problems in 2005 are as follows:
Disease Control Issues
• Optimum disease control this year has got to come from programmes
tailored to disease pressure, drill date, rotational position, location and soil
type.
• Do not allow disease to become established so early application is critical i.e. T0 on Septoria, Mildew or Yellow rust prone varieties such as Consort,
Claire or Robigus.
• Although there’s a lot of talk about reducing dose rates, this year will not be one to experiment, so maintain dose rates, especially for triazoles on
Septoria tritici prone varieties, at least at 50% for T1 applications, 75% for
T2s and 50% for T3s.
• Target strobilurins to disease, location and variety. Apply minimum dose of
50% T1/T2 and 30% T3 to optimise disease control and physiological effects.
• Timing and spray intervals are critical. Link timing to leaf emergence not calendar date. Do not extend intervals beyond four weeks - this may have to
be shorter if rates have been compromised.
• Utilise alternative modes of action e,g, chlorothalonil, boscalid,
fenpropimorph, mancozeb etc.
There will be a high seed population in the ground for 2005 as a result of the
explosion in numbers last year. Effective Brome treatment is essential - 5 plants/m2 can reduce yields by more than 1t/ha.
Different types of Brome require different treatment approaches. Make sure you have professional help to identify the problem accurately.
Make sure you spray early. You can easily lose up to 40% of yield by leaving
treatment too long.
Leave the appropriate interval between sprays. 22 days is the optimum as this allows sufficient re-growth before the second application.
Don’t forget to treat the problems sufficiently in set aside land. Complete prevention of viable seed production of Brome is possible with correct programmes of glyphosate.
Orange Blossom Midge Issues
It is estimated £55 – 60 million of lost revenue resulted from midge attack in 2004 - 6% of the total UK Wheat crop.
Many farms were unaware of their yield losses from midge attack last year. 5 – 10% loss could have easily gone undetected where a resistant variety was not grown as a check on potential loss.
Well over 50% of UK crops had more than 5% grains attacked despite a quarter of all areas receiving an insecticide for midge control.
High egg burden in soil is a major threat for 2005. Highest risk areas are those with an average June temperature of 14°C or above – mainly lowland areas south of the Tyne river.
Different wheat varieties have different levels of susceptibility. Professional help is required for correct identification and treatment strategy. |
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