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Strobs are key to unlocking OSRs yield potential

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Strobs are key to unlocking OSRs yield potential

18/03/2015

Article taken from the Agronomist & Arable Farmer

Prudent use of oilseed rape fungicides that exhibit physiological benefits as well as control of yield robbing diseases such as Sclerotinia, light leaf spot and verticilium must be prerequisite to maximising gross margins this year, says Agrovista agronomist Graham Edwards.

In the autumn he applied Frelizon, which has given excellent control of phoma and light leaf spot.  But, autumn fungicides have now run out of steam and crops might need a second application for light leaf spot.

“ADAS warnings have already been released for light leaf spot this spring with current weather conditions lending themselves to this becoming another high threat year,” says Mr Edwards.

“For Sclerotinia control growers must adopt a minimum of a two-spray programme that provides cover for the whole of the flowering period.  Galileo (picoxystrobin) is the first spray at early flowering, which is the foundation of the programme, followed by a second spray two to three weeks later with a fungicide such as Recital (fluopyram + prothioconazole).  In addition this approach will cover us for other disease such as alternaria and botrytis.

“On a similar vein to the physiological benefits experienced from using strob chemistry in wheat, picoxystrobin has a similar effect on oilseed rape.  Keeping the crop greener for longer adds valuable yield, which can be as high as 0.9t/ha, but importantly providing up to 75% Sclerotinia control as well,” says Mr Edwards.

The price of oilseed rape has dropped considerably this year, but if it is in the ground and has good potential it is going to need protection.

“Yields of 5t/ha are not unrealistic provided there is an appropriate level of crop management,” says Mr Edwards.  “Oilseed rape is not a cheap crop to grow, however, and with some crops requiring multiple fungicide sprays a season, inputs must be managed appropriately.  With all inputs under scrutiny the one not to cut out is the Galileo spray, because in the absence of disease it more than pays for itself.  This claim is backed by DuPont, Agrovista and Independent trials.”

Galileo encourages better nitrogen uptake by increasing the plants’ ability to scavenge; it provides early control of Sclerotinia and light leaf spot, and extra greening makes the plant better able to utilise nitrogen.

Sclerotinia is one disease that Mr Edwards says is very much on his radar – increasingly so – as tighter harbouring inoculum have seen the disease appear in all major oilseed rape growing areas.  Sclerotinia can take out at least 30% yield if sprays are badly timed or ignored.

“Sclerotina is so massively damaging and for the relatively small cost to keep on top of it with a strobilurin fungicide such as Galileo, it’s no brainer,” Mr Edwards stresses.