Poster Presentation Science Protecting Plant Health 2017

Development of an effective delivery system for a woody weed bioherbicide (#351)

Victor J Galea 1 , Peter Riikonen 2
  1. University of Queensland, Gatton, QLD, Australia
  2. Bioherbicides Australia Pty Ltd, The University of Queensland, Gatton, Qld, Australia

“Di-Bak Parkinsonia” is a bioherbicide product developed for the management of the invasive woody weed Parkinsonia aculeata in rangeland situations in Australia. The product is formulated as a food grade gelatine or cellulose capsule containing various native fungi associated with naturally occurring dieback events in northern Australia. When introduced into non-symptomatic trees, these fungi are capable of colonising parkinsonia endophytically leading to the development of a naturally spreading dieback event in the population.

Effective colonisation of parkinsonia plants requires the capsule to be inserted into the stem and sealed to maintain a moist environment free of oxidisation and desiccation. A mechanised delivery system powered by an 18V cordless drill allows the operator to quickly and effectively drill a hole, insert the capsule and seal the inoculation site with a plastic plug. The delivery system has undergone several developmental steps and robust field testing which has benefitted from suggestions provided by field staff experienced in woody weed control.

A series of work rate evaluations were conducted under field conditions in a parkinsonia infestation at Corporal Dam at Alexandria Station, Barkly Tablelands in the Northern Territory. Two operators each using a mechanical inoculating apparatus, and working in a team were capable of an average work rate of ranging between 101 and 145 trees per hour each. Battery performance ranged between 210 to 240 inoculations before a changeover was required. Overall work rate was considered to be as good, if not better than that which could be achieved by basal bark treatment with conventional (synthetic) herbicides using a backpack sprayer.