Rural Industries Research & Development Corporation

Research Compendium 1993 - 1994

Research Project

DEVELOPMENT OF CONTROLLED RELEASE NEMATICIDES

Objectives

• To formulate cost-effective controlled release nematicides.
• To develop a rapid biological assay to detect levels of nematicides and residues of new controlled release nematicides.
• To identify the amount of controlled release nematicide needed to keep parasitic nematodes below an economic threshold.

Background

While plant parasitic nematodes will ideally be controlled by 'non-chemical' methods, there will be a continuing need for minimal use, low cost, environmentally safe nematicides which can be integrated with other control measures such as resistant cultivars or crop rotation.

These newer nematicides will probably be formulated as controlled release granules, because they are considered to be safer than other formulations. Controlled release formulations, as their name implies, release small amounts of their active constituent in localised areas over long periods ranging from weeks to years.

Research

Two controlled release formulations of the non-volatile nematicide carbosulfan (F M Corporation), containing 18.6% and 44.2% of active constituent were developed for an evaluation against the entomopathogenic nematode Heterorhabditis bacteriophora. A nematode bioassay was developed, using either a terrestrial or an aquatic system, and the mortality of nematodes was assessed after they had been exposed to the controlled release formulations for varying periods of time. The tests were also conducted for comparative purposes, using conventional formulations of the same nematicide-active constituents developed by the manufacturer.

Outcome

• Two controlled release granular formulations of carbosulfan were prepared in a silica matrix.
• A rapid bioassay was successfully developed to screen controlled release and other formulations of non-volatile nematicides using the entomopathogenic nematode Heterorhabditis bacteria.
• Results show that the formulation containing 18.6% of active constituent of carbosulfan was the more effective of the two formulations developed in control of nematicides.
• Both formulations were potent insecticides, with 44.2% active constituent the most effective.

Implications

Controlled release formulations of the non-volatile nematicide carbofuran have been shown to be effective in these tests. Further work is required on the controlled release nematicides developed during this project to identify the right eutectic mix of controlled release and conventional nematicide for target crops such as perennials and methods of application such as bare-root dip or irrigation.

RIRDC Project No: DAV-43A

RESEARCHER: Dr Jillian Hinch

ORGANISATION: La Trobe University

PHONE: 03 479 3093

Last updated: 10 October 1996
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