The escalating cost of glyphosate and the potential to significantly reduce combine fuel costs mean that oilseed rape growers should consider switching to Reglone for desiccation of their crops this harvest.
Whilst glyphosate has been a cheap herbicide option in recent years, a global shortage of supplies has seen prices rising substantially this season, reports Syngenta Technical Manager, Iain Hamilton. Combined with the increased value of rape, more growers will want to utilise the agronomic benefits of Reglone as a true crop desiccant, he believes.
Mark Palmer of Agrovista agrees that Reglone (diquat) is a far superior desiccant for oilseed rape crops, especially in drying out stems to facilitate faster and cleaner combining. "Glyphosate is a relatively poor desiccant in many of the oilseed crops where it is most needed," he says. "Translocation can be adversely affected in diseased or lodged crops with kinked stems, leaving greener stems when pods are ready for harvest. Application on hot summer days can also reduce translocation through the plant." The contact activity of Reglone leaves drier brittle stems
Combine drivers battling through green stemmed rape crops will bear testament to the increased fuel consumption required to cut and chop the crop; Reglone treatment has been shown to improve combine speed and reduce fuel use by up to 20%. "Timely harvesting of oilseed rape crops will be even more important this year, so as not to compromise cutting of high value wheat crops," advises Dr Palmer.
He reports that efficacy trials with the adjuvant, Companion Gold, has consistently achieved 10 to 15% yield increase with Reglone application. He attributes this to a giving a more even ripening that enables easier harvesting, with reduced pod shatter and seed loss. Companion Gold is the only adjuvant to have on-label approval for use with diquat (and glyphosate) authorized by PSD and supported with both residue and efficacy data. It is a multi-functional adjuvant, combining surface wetting and water conditioning with drift reduction based on a unique patented polymer.
"Spray operators have also reported significant drift reduction when using Companion Gold. It's is a valuable help when spraying tall rape crops, or trying to catch up with desiccation in a difficult season," he adds.
Iain Hamilton of Syngenta advises the optimum timing for Reglone application will be when 90% of the seed in the mid-layer of pods are reddish brown to dark brown, with a few seeds black and the remaining 10% will be green but must be firm and pliable. Seeds in the upper pods will be predominantly green, and pliable, with lower pods brown to black seed.
Heavy and lodged crops are especially suitable for Reglone desiccation, with application timing dictated by seed colour in the more mature pods exposed to sunlight. In dense crops spray operators should use higher water volumes to ensure good crop penetration and coverage, he adds.
Mr Hamilton highlights that with modern oilseed rape varieties, Reglone application timing is typically seven days later than swathing, which could allow crops time to add extra seed weight and increase oil content.
