Challenging Condition Research Highlights Modern Glyphosate Advantages

July 2006 - Modern Roundup formulations have major advantages over traditional glyphosates in meeting the challenges of today's high pressure arable systems, reveals the latest specialist research.

The research, published by Monsanto this summer, involves extensive trials examining glyphosate performance under a range of challenging conditions - with rainfall soon after application; with restricted cultivation intervals; under hot, cool and dry conditions; and in hard water.

It shows modern, high concentration liquid and dry Roundup formulations to be markedly superior to glyphosates based on either the original ethoxylated tallow amine or more recent phosphate ester formulations in their efficacy and speed of action as well as safety and convenience.

"Our trials focus on the tough conditions under which non-selective herbicides have to perform in today's arable systems with their particular workload, timeliness and cost pressures," explains Monsanto technical adviser, Manda Sansom.

"Almost everyone is handling far larger acreages with far fewer men and machines these days. The sheer scale of autumn workloads is driving growers to earlier drilling too, while modern agronomy has progressively extended cereal ripening time, pushing the wheat harvest back by around two weeks.

"Growers could count on a month or more between successive combinable crops not so long ago, but many now have barely 3 weeks," she points out. "Which really puts the pressure on stubble and stale seedbed weed control. And it does so at a time when resistance challenges are making good out-of-crop weed control more vital than ever.

"These conditions are very different from those for which we originally developed glyphosate more than 30 years ago. Since then we have progressively improved our Roundup formulations to deliver greater, more reliable and consistent weed killing power faster, more economically and more safely.

"In the latest series of trials we've put these to a series of challenging tests to prove just how much better they are than the generics which remain firmly rooted in old formulation technology."

While all the glyphosates tested gave almost complete control of common couch with no rain after application, this was maintained at over 90% with Roundup formulations based on the latest patented surfactant technology even with rain after just 30 minutes. In contrast, control with traditional formulations at the same active ingredient concentration fell to a disappointing 75%-80%.

Under the particular challenge of hot and dry spraying conditions, the trials also showed traditional glyphosates giving a good 20% less weed control than equivalent applications of branded Roundup. As they did in hard water, particularly so at the most challenging high water volumes and low dose rates.

Side-by-side comparisons with 195 different weed species further showed 10% better long term control of the hardest to kill perennials with the Roundup formulations. And much more rapid uptake and translocation was confirmed in annual grass weeds in particular.

"The evidence is very compelling," insists Manda Sansom. "Modern Roundups just work a while lot better than traditional glyphosates under the challenging weed control conditions of today.

"What's more, this superiority adds up to real benefits in practice. For instance, the value of a herbicide that is rainfast in just one hour and allows cultivation after only six cannot be under-estimated. Especially so, if it also tolerates hard water and works equally well in both hot, dry and cool, dry conditions.

"With Roundup Ace, Klik, Gold or Max you can be assured of consistently good weed control under the toughest of conditions, with the shortest of spraying windows and the briefest of cultivation intervals (Table). Which means more flexibility, faster turnround times, greater peace of mind and less need to re-spray.

"Any of these advantages could easily be the difference between success and failure on most units today, with field work, spray windows and spray operator availability as tight as they have become," she observes.

"Add the savings in time as well as storage, transport, and packaging disposal costs from the more concentrated and convenient Roundup formulations and their extra value over generics is crystal clear. All the more so for the fact that hectare for hectare they often work out no more expensive."

Table: Glyphosate Formulation Usage Recommendations