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OSR MANAGEMENT LAGS BEHIND
Date added: 12/03/07 |
Whilst the UK’s top arable producers made serious progress in terms of production and profit with Winter Wheat last year, Oilseed Rape is standing still and has been for many years, says ProCam agronomist Nick Myers.
Speaking at the company’s Spring Conference in Newmarket on March 7th, Mr. Myers urged all Oilseed Rape growers to pay more attention to the crop and its management.
In 2006, ProCam’s best Wheat growers achieved increases in margins/ha of over 50% whereas in Oilseed Rape, the increase was less than 18% - from £404.56/ha in 2005 to £474.46 in 2006.
“Although yield potential of varieties on Recommended Lists has risen significantly over the last 20 – 25 years, yields produced in the field have changed little over that period. Genetic potential has added about one tonne/ha to potential yield but even top growers have been lucky to realise
1/2 tonne/ha in reality.
“One reason, could be that growers aren’t using fungicides effectively on Oilseed Rape. In Recommended List trials, a minimum of 3 fungicide sprays are used over the course of the season but on most farms, crops receive 1.8 applications on average. In 2005/06 4cast figures showed growers used 2.3 fungicides on average with only the top performers getting up to 4 applications.
Farmers seem to have got the message about the relationship between fungicides, yields and economics in Wheat, but turn a blind eye when it comes to Oilseed Rape, Nick Myers said.
“The results are the same. Timing of fungicides is critical but so is the number of applications, with 4cast showing a yield advantage of approximately one tonne/ha between a one-spray and a four-
spray programme.”
Fungicides have a primary disease control function but some can also have major effects in preventing lodging, promoting root growth and managing the canopy. Oilseed Rape growers don’t realise the implications of over-dense canopies, he said.
“A relatively open canopy at, and just after, flowering is important as photosynthetic activity of the leaves is what increases seed numbers and size. In dense canopies the flowers will reflect 80% of the available light. A Green Area Index (GAI) of 3.5 is thought to be optimum for light interception.
“Seed numbers in Oilseed Rape relate directly to the amount of light that can be intercepted by the green tissue within the crop soon after mid-flowering.
Fungicides, used properly, are a main tool in manipulating canopy growth and efficiency.”
Spring applied Nitrogen has the main effect on canopy size and yield and there is growing evidence from 4cast that there are benefits from later N applications.
Delaying the first application from February to March showed a yield advantage of 0.2 tonne/ha in 2006. Fields where specific late N was applied at flowering produced an additional 0.4 t/ha.
“With Oilseed Rape poised to be an important food and Bio-fuel (biodiesel) crop in the future, it’s time we all woke up to its management and gave it as much priority as we do Winter Wheat,” Nick Myers concluded. |
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