Northern croppers have a lot to think about when applying broadleaf herbicides on winter and summer fallows – of course, their effectiveness on weeds, particularly from some traditional options; plantback intervals; one-pass applications with brews containing grass herbicides and any related antagonism; their volatility and application restrictions in sensitive cropping areas; and weather conditions after spraying.
Fortunately, the recent registration of a dual mode of action broadleaf herbicide, including for the popular optical spot spraying of winter and summer fallow weeds, is set to simplify the decision-making for growers and they can take advantage of it leading into summer cropping programs this season.
Monsoon, developed by Adama Australia, is a unique co-formulation of two proven active ingredients, bromoxynil (Group 6) and fluroxypyr (Group 4), which has demonstrated excellent control of a wide range of difficult broadleaf weeds, vines and woody weeds.
It also can be combined with a range of compatible tank-mix partners, with minimal impact on the efficacy of grass herbicides and without the volatility concerns or re-cropping limitations of some alternative options.
Adama Australia southern Queensland market development manager Jim O’Connor, says trials with Monsoon in northern NSW and the Darling Downs region in Queensland have shown strong activity on volunteer cotton, fleabane and saltbush, and he expects it will become another important tool in weed control programs with optical spot sprayers.
He says Monsoon will be particularly useful to cotton growers due to its excellent activity on GM cotton volunteers and a range of hard-to-control weeds. Monsoon can be successfully tank mixed with grass control partners such as glyphosate, glufosinate and Group 1 chemistry for robust control of susceptible summer grass weeds at early growth stages.
“There can be some antagonism when using Group 4 chemistry with grass control herbicides, however it is reduced when using fluroxypyr in combination with bromoxynil, especially at lower use rates,” Jim says.
There is also reduced carryover risk associated with these active ingredients, with the re-cropping periods following Monsoon application set at seven days through to 28 days according to application rate and rotation crop type.
“It has a nice rate range with optical spot sprayers up to 4L/ha, so growers can go with a high dose if needed or use a lower rate to further reduce the re-cropping interval,” he adds.
“Growers will be able to spray in front of upcoming plantings of major summer crops including cotton, sorghum and mung beans.
“In addition to volunteer cotton and fleabane, Monsoon will also help target hard-to-control broadleaf weeds on summer fallows using optical spot sprayers, and it will be ideal in areas where there are use restrictions on 2,4-D herbicides, including where there are summer plantings of cotton and other crops like grapevines and tree crops.
“However, growers will still need to employ excellent spray application practices.”
Jim says the combination of the two active ingredients also demonstrates success against saltbush, sowthistle and ipomoea vine species, while bromoxynil (Group 6) chemistry is not often used on northern fallows, which will help maximise herbicide efficacy.
“It presents an opportunity to get a different chemical group involved in fallow programs,” Jim explains.
“Monsoon applications are also robust in a range of suitable meteorological conditions, whereas alternative herbicide efficacy can vary depending upon conditions.”
Jim says growers are having to decide over the use of traditional herbicides, different brews and various products under permit with their fallow weed control applications, so the registration of Monsoon for use with optical spot sprayers is timely.
Monsoon is also registered to be applied in winter cereals, targeting broadleaf weeds in post-emergent applications, and work is underway to add use patterns in sugarcane and sorghum to the product label.
For further information on Monsoon herbicide applications in fallows and winter cereals, growers and advisers can contact their local ADAMA Australia representative or visit ADAMA.com
