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Blue Bags Grow Better Crops

LATE DRILLING WINDOW GIVES OILSEED RAPE OPPORTUNITIES

It’s not too late for growers to take advantage of the recent rise in oilseed rape prices and increase their area of the crop for 2017, advises Mike Mann of Downham Market based seed specialists DSV UK.

 

Despite the trend for ever earlier drilling following the neonicotinoid ban, crops can be sown throughout the middle period of September provided the right variety is chosen and seedbeds are well prepared, he says.

"Oilseed rape has had a hard time over the last couple of years and despite the relatively cold conditions reducing yields in the region this year, many growers are saying they’re now planning to up their areas for next year."

"The lift in prices towards the £300/tonne mark has obviously helped but there’s also growing awareness that viable alternatives to the crop are few and far between."

Hybrids have again performed well this year with many crops of the established high yielder Incentive topping the 5.0t/ha mark and demand for Clearfield varieties has risen considerably, he says.

"Choose a proven hybrid with good early vigour and root development properties, prepare a fine seedbed with adequate moisture and plants should get away cleanly and quickly and be able to grow through most early pest and disease problems."

In fact, there’s a strong school of thought that drilling later avoids the worst of the late summer insect and aphid populations, Mike Mann points out.

"You’ve got to keep an eye on threshold levels and be prepared to spray when necessary, but within reason, the later you drill the more likely you are to avoid issues such as turnip yellow virus and serious flea beetle attack."

According to CF Fertilisers’ agronomist Allison Grundy, growers choosing high performance hybrids for later drilling situations should pay particular attention to plant nutrition.

"Sulphur use in oilseed rape has increased in recent years but there are still significant areas of the crop that do not receive any at all despite all the evidence of its effect on yield."

"With current Sulphur deposition virtually at zero over much of the country, crops are more than likely being held back by this."

For the modern high yielding hybrid varieties needed for later sowing, adequate Sulphur is absolutely critical, she says.

"In the most recent ADAS trials funded by AHDB and industry partners, applying Sulphur fertiliser lifted yields from about 1t/ha to 5t/ha in one case and up to a similar level from about 1.5t/ha in another. The optimum rate was found to be in the region of 50-75kg SO3/ha."

 Importance Of Sulphur for OSR

"The Sulphur was also found to significantly improve oil content with a lift from 39% to 45% at one site and from 42% to 45% at the other." 

CF Fertilisers recommend a minimum 200kg/ha of DoubleTop (60kg SO3/ha) for most applications with up to 375kgs/ha (112kg SO3/ha) required for very deficient sites.

But it is not just Sulphur that is important in OSR, she says. Additional work by ADAS has shown that accurate Nitrogen management is essential in lifting yields and managing canopies.

“The key conclusion is that managing Nitrogen inputs to target a Green Area Index (GAI) of 3.5 by flowering increases Oilseed Rape yields by up to 0.36t/ha.”

But to achieve maximum yields and oil contents consistently, growers must know precisely how much Nitrogen to apply, she says.

“The only way you can do this is to undertake N-Min testing in spring to establish a measured  SNS – soil nitrogen supply – and work out rates from there.

 N-Min to assess Soil Nitrogen Supply

“With oilseed rape becoming an increasingly valuable crop again, taking shortcuts with nutrition this coming season will be simply throwing money down the drain.”