Amenity managers and contractors should plan weed control operations carefully in catchy spring weather, warns Monsanto, manufacturer of glyphosate herbicide Roundup ProVantage.
Technical Development Manager Barrie Hunt explains: “Following a long, cold and wet winter the forecast now looks more promising, but May can still bring high diurnal temperature ranges and overnight frosts. Applying glyphosate too early can lead to reduced weed control.”
Mr Hunt points out that knowing how glyphosate works can prove very helpful in understanding how performance varies in different situations.
“Glyphosate works by leaf uptake and translocation to the growing points in both shoots and roots.”
“Plants need to be healthy and have sufficient leaf growth to absorb the Roundup. Perennial plants like thistles, nettles and dandelions were late to emerge from winter dormancy this year and seed germination has been delayed due to cold soil temperatures. Spraying by the calendar can result in herbicide being applied before sufficient leaf area has emerged.”
The variable weather can also slow the effects of herbicide applications.
“Even with good leaf coverage, low soil temperatures and high diurnal air temperature ranges resulting in slow plant growth mean visible symptoms can take up to four weeks rather than the expected 10-14 days. However, the end result will be the same.”
Best practice in application is also important, comments Mr Hunt.
“Operators should pay close attention to correct water volumes and proper sprayer calibration, choosing appropriate nozzles and avoiding drift for optimum efficacy.”
Roundup ProVantage helps amenity professionals meet the challenge of catchy conditions. It is more concentrated at 480g glyphosate per litre and the optimised blend of surfactants as well as the high loading makes it Monsanto’s most advanced amenity glyphosate.
Superior performance includes improved rainfastness and speed of uptake. Rainfast in one hour for annuals and four hours for perennials, Roundup ProVantage reduces the risk of run off from that unexpected shower and ensures the maximum amount of glyphosate reaches the roots for the optimum effectiveness. It also offers reduced off-target exposure through 33% less drift, giving operators the confidence to apply in a wide range of groundcare situations.