Cereal crops can quickly become susceptible to broadleaf weed escapes during crop establishment, making Callisto pre-emergent herbicide a valuable addition to many wheat and barley programs.
A new label extension now includes oats and triticale in the list of registered crops, along with an updated use pattern, says Syngenta technical services lead James Considine.
Readily tank mixable with specialist knockdown herbicides, he said Callisto offers extended in-crop residual action to manage multiple germinations until growers or contractors can make a foliar application.
“The big advantage, and feedback we’ve had from growers, has been that missing logistical piece in that they can put Callisto out with their pre-emergent grass weed herbicide and their knockdown products to cover a gap.
“They're not having to rush back to that paddock and get those broadleaf weeds under control so early, when Callisto is really taking the pressure off that post emergent application.”
Callisto pre-emergent herbicide is a Group 27, 4-hydroxyphenyl-pyruvate dioxygenase (HPPD) inhibitor that forms a layer in the soil, where it is readily absorbed by the roots of emerging broadleaf weeds, disrupting photosynthesis.
Mr Considine said weeds that emerge through this treated soil appear bleached, making Callisto effective and highly visual, enabling advisors to achieve demonstrable results. Depending on the farmer’s cropping system, he said it made a lot of sense to use Callisto pre-emergent rather than a HPPD inhibitor as a post-emergent spray.
“We don't see a lot, if any residual activity, with those foliar HPPD sprays so that's a real benefit of getting Callisto into our programs – we're able to get control of multiple germinations, and we know a number of those key broadleaf weeds will have multiple germinations throughout that season,” Mr Considine said.
Callisto pre-emergent herbicide was first registered for use in wheat and barley, incorporated by sowing (IBS). Registration has now been extended to oat and triticale crops.
Callisto controls weeds with confirmed resistance to other modes of action, including Indian hedge mustard, wild radish, wild turnip, capeweed, fleabane, prickly lettuce and sowthistle. It also controls volunteer chickpeas, volunteer faba beans, volunteer field peas, volunteer vetch, volunteer lentils, lesser loosestrife, serradella, shepherd’s purse and sub clover, as well as double gee at the higher label rate.
Mr Considine said that like with any IBS pre-emergent herbicides, weeds might still emerge in the furrow, but can be effectively managed with economical post-emergent herbicide application.
“What we've commonly seen in commercial jobs, and at Syngenta Learning Centres, is something as simple as MCPA LVE is a quite economical option to tidy up those weeds in the furrow,” he said.
The updated Callisto label also allows for a split application – IBS and post-sowing, pre-emergence – which Mr Considine said provided added flexibility for advisors and growers to manage weeds in the furrow.
With long in-season residual activity, Mr Considine said Callisto is highly advantageous in knifepoint, press wheel sowing systems.
Applied to the soil no more than three days prior to sowing, Callisto is absorbed by the roots of broadleaf weeds. Soon after germination, photosynthesis rapidly brings on the tell-tale bleaching.
Mr Considine said Callisto was a highly economical choice, with the choice of a 100 ml/ha and 200 ml/ha use rate. The higher rate offers residual out to eight weeks, equivalent to $1.97/ha, per week of control.
“Growers have been really excited about being able to get some residual broadleaf weed control in their cereal crops, and putting that product in with their pre-emergent grass herbicides like Boxer Gold,” he said.
“From a compatibility perspective, Callisto has an excellent profile there, we've done a range of our own internal testing, and then the past two seasons we've obviously had a lot of in-field testing with growers using it with knockdowns such as Gramoxone 360 Pro and Kelpie 550 glyphosate.
“On a commercial scale, we've had excellent results with a range of pre-emergent grass products that you'd commonly use, including our own Boxer Gold pre-emergent grass weed herbicide.”
Victorian Mallee farmers Adam and Corey O’Callaghan were among the first to use Callisto in conjunction with Boxer Gold. “We’ve used quite a lot of Boxer Gold, it’s a pretty good pre-em, compatible with everything,” Corey O’Callaghan said.
“And that’s a pretty good combination really,” said his brother Adam. “(With Boxer Gold and Callisto) you’ve got your grass and your broadleaf, and we’ve said that’s our ‘go-to’ moving forward.”
Mr Considine urged advisors to conduct their own side-by-side trials for their clients to see the benefits too. “The results are something you really have to see for yourself, giving growers considerable benefits when it comes to logistics at a busy time of year,” he said.
