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Department of Employment, Economic Development and Innovation

BIOLOGY, CULTURING & FIELD RELEASE OF PUCCINIA SPEGAZZINII: A CLASSICAL

BIOCONTROL AGENT FOR MIKANIA MICRANTHAKUNTH (MILE-A-MINUTE) IN PNG

A. Kawi (NARI PNG)K. Kurika (NARI PNG)J. Moxon (NARI PNG)J. Saul-Maora (CCI PNG)J. Fidelis (CCI PNG)M. Day (BQ Aust)

2© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

M. micrantha origin & ecology

• Asteraceae• Native to tropical America• Aggressive vine - grows 1 m/month• Grows to ~1200 m altitude• Spreads vegetatively & by seed• 000’s seeds by wind & machinery

3© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

M. micrantha distribution & impact

• 17 South Pacific island countries• Most SE Asian countries• Australia (NQ) – under eradication• Plantations & subsistence farms• No. 1 weed in oil palm and cocoa• Cause 10-20% reduced yield• 5% potential yield loss – loose fruit• Losses up to $10 million p.a.

4© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Project Background

• Project commenced in 2006• Funded by ACIAR managed by Qld

Govt.• Involved PNG & Fiji• Aim to reduce weed impact via

introduction of biocontrol agents

5© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Puccinia spegazzinii

• Autoecious, microcyclic rust• Ex eastern Ecuador• Tested by CABI-UK for India &

Taiwan• Tested further for PNG & Fiji• Imported into Fiji & PNG Nov 2008• Culturing method developed in PNG

6© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Culturing method

• 3-4 week old cuttings with 3-4 pairs of leaves placed under large plants with mature pustules

• Left in sealed perspex box for 48 hrs @ 26oC

• Placed in screenhouse for pustules to develop

7© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Chlorotic spots after 6 days

Teliospores after 11 days

Basidiospores after 15 days (3 mm)

8© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Field inoculation method

• 50 cups placed in field where rust is well established

• 10 cups removed each day• Plants held for pustule

development• Plants left in the field for 4-5

days gives good infection

9© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Comparative growth experiments (PNG)

• Paired trials using inoculated & control plants

• Height/length of stem• No. nodes• Dry weight• Single- & multiple-stem plants• Quarantine, Shadehouse, full sun,

under cocoa

10© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Comparative growth experiments (PNG)

Screenhouse Cocoa Block

Screenhouse Cocoa Block

11© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Field Releases & Establishment

• Released widely >520 sites in 15 provinces in PNG

• Pustules at ~130 sites, in 9 prov. & spread 37 km

• Some prov. still to check• Poor establ. in dry areas• Releases & monitoring continuing

12© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

P. spegazzinii status in PNG

13© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Field Monitoring (PNG)

14© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Future Activities

• Project extended to Dec 2011• Continue to rear & release rust• Check release sites for establishment in all provinces• Continue to collect data from detailed monitoring sites• Monitor spread of the rust• Conduct surveys in areas where mikania is controlled• Potential for other countries where mikania is a problem

• e.g. China, Taiwan, India, Solomon Islands & Vanuatu

15© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Summary

• P. spegazzinii is host specific• Easy to culture in lab & field• Significantly reduces growth rate• Reduces % cover at some sites• Widely distributed and spreading• Potential to control mikania in

wet areas• Has potential for other countries

16© The State of Queensland, Department of Employment, Economic Development and Innovation, 2010

Acknowledgements

• ACIAR• PNGOPRA• NARI Regional staff• PNG Provincial officers• Dr Carol Ellison, CABI Europe-UK