A RECENT study conducted by cesar and Advanta Seeds has found three popular neonicotinoid insecticide-based canola seed treatments offer the same protection from green peach aphids, and the coatings offer superior protection compared to no treatment.
The research, headed by cesar director and entomologist Paul Umina, showed no significant differences between Cruiser Opti, Poncho Plus and Gaucho seed treatments, and all had high levels of protection against GPA for up to eight weeks after seedling emergence.
Additionally, seedlings treated with Cruiser Opti, Poncho Plus and Gaucho showed lower plant damage than seedlings in the untreated controls.
The trial was conducted by the research team using a microcosm approach under shade-house conditions across a five-month period.
Advanta Seeds canola business manager Justin Kudnig said the results were timely given recent outbreaks in southern Australia.
“Following the costly outbreak of beet western yellows virus in southern Australia in 2014, Advanta Seeds worked with cesar for the first time to clear up any confusion on seed treatments and their suppression of GPA,” he said.
Mr Kudnig said the research was one of six fields under investigation under its wider Innovative Crop Solutions banner.
“Our ICS team investigates industry issues by conducting professional, technically sound research and providing advice, recommendations and realistic economic solutions for growers, consultants and agronomists throughout Australia.”
GPA (Myzus persicae) is a pest in a variety of broadacre crops and controlling it relies heavily on the application of broad-spectrum pesticides.
But increasing GPA resistance to multiple chemical classes, including carbamates and synthetic pyrethroids, is widespread across Australia. The cesar team has recently discovered field populations of GPA that have evolved resistance to neonicotinoid insecticides.
Dr Umina said though the trial results were convincing, it was important to note the trial was conducted on aphid ‘biotypes’ that have no insecticide resistance.
“The efficacy of some insecticide seed treatments could be much lower against field populations of aphids with resistance,” he said.
Dr Umina said the trial was also conducted under ‘semi-field’ conditions, and therefore the length of protection may not correlate to all field situations and growing conditions.
“Monitoring of seedling canola crops is recommended even when using insecticide seed treatments on canola,” he said.
“This is particularly the case in seasons that follow considerable summer rainfall, which tends to provide a green bridge of weed hosts for aphid survival.”
