Over the last few seasons, SACOA has been conducting research into aphid control with BIOPEST® in canola.

While the yield loss from aphids transmitting Beet Western Yellow Virus (BWYV) still causes conjecture, it is generally understood that the earlier aphids come in, the greater the yield loss may be at the end of the season.

BIOPEST® is a highly refined biorational pesticide designed for use as a carrier, fungicide, insecticide and to manage aphid-transmitted viruses such as BWYV.

BIOPEST® is a medicinal quality paraffinic oil which has not been previously available in Australia for this type of application.

Mode of Action

As a biorational pesticide, BIOPEST® has two key functions in the management of aphid-borne viruses:

• Plant Virus Controller
  Stylet-borne plant viruses can be transmitted by the probes of winged aphids in less than 20 seconds after landing on the upper leaf surface of host plants. BIOPEST® interferes with the virus transmission process preventing the pest from inoculating healthy plants and transmitting the virus from diseased ones.
• Insecticide
  BIOPEST® effectively manages aphids in two ways:
  • Behaviour modification, primarily by modifying insect feeding and egg laying behaviours
  • By suffocation (anoxia)

How Behaviour Modification Occurs

Plant feeding insects use hollow hairs (‘sensillae’) to detect special chemicals in plants, which identify the plant as a host or non-host. Contact with these plant chemicals can trigger critical insect behaviours such as feeding and egg laying.

BIOPEST® acts to plug the hollow pore on the end of these hairs thus removing the insect’s ability to communicate with any potential host plants. As beneficial insect host-sensing mechanisms differ from pests, they are minimally affected by BIOPEST® application (however, if enough oil contacts a beneficial insect, mortality may occur).

Aphid Control Results

SACOA’s research in the past two seasons has demonstrated BIOPEST®’s control of Cabbage/Turnip Aphid and Green Peach Aphid (GPA). In 2014 in Moora, while the total population of GPA was not as high as previous years, BIOPEST® offered equivalent control to current standards (see Chart 1).

In 2013 when Cabbage/Turnip Aphids were dominant, aphid control with BIOPEST® was equivalent to current standards (see Chart 2).

Interestingly, the greatest yield improvement over the control was in the plot that had the highest numbers of aphids when the treatments were applied, however the trend was not consistent across all treatments (see Chart 3).

Using BIOPEST^® as a Preventative

• Include BIOPEST® at 1% as a tank mix partner with a post emergent herbicide or fungicide.

The benefit of the tank mix is two fold – there is improvement in coverage as BIOPEST® will act as a deposition agent and as it provides activity in its own right (on aphids and disease), there is reduced resistance selection pressure on the conventional active and beneficial populations are maintained. The other benefit of the combined aphid and disease control is the single pass and the timing.

Using BIOPEST^® as a Curative

• One standalone spray of 2% BIOPEST® on a developing population.
• Tank mixes of 1% BIOPEST® with conventional insecticide will provide synergy and protect the active from resistance development.

Ensuring Optimal Results

• Use a water rate of approximately 80 – 100L/Ha.
• Adjust tractor speed to achieve thorough spray coverage to the point of runoff.
• Always use constant agitation in the spray tank. Never leave a spray tank of oil and water overnight.
• Always refer to product label(s) for specific details on correct use and compatibility.
• The re-entry interval (REI) for BIOPEST® is 4 hours.
• BIOPEST® has no residue tolerance.

Future Research

SACOA are conducting extensive research into the role of BIOPEST® in broadacre crops. This work will evaluate effects of BIOPEST® as a standalone treatment for insect and disease control and as a synergistic tank mix partner to improve the efficacy and extend the mode of action of a range of existing insecticides and fungicides. In 2015, this includes investigating Sclerotinia and aphids in replicated canola trials.

References

Peracto SAC00114 – Moora, Oct 2014
SACOA internal trial – York, Aug 2013