This is a final research report from Hort Innovation’s historical archives. Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.

What was it all about?

The work program included: An assessment of new “soft options” as additional components of Integrated Pest Management (IPM); Identifying naturally occurring beneficial organisms (natural enemies) which have the potential to contribute to sweet corn IPM systems; Conducting a Disease Survey of the Industry; and Developing and testing improved IPM strategies, which included new “soft options” and the enhancement of naturally occurring beneficials.

The need to manage 'secondary' pests and diseases, whilst maintaining and/or improving the management of helicoverpa, was identified by the sweet corn industry in May 2001 (at the completion of VG97036). Subsequently the IPM project, “Improved IPM Systems in the Australian Sweet Corn Industry” – VG05025 was funded to build on these outcomes and to further understand the complexity of IPM in sweet corn, by focussing on the broader range of insect pests and their management in an IPM context.

The R&D work program demonstrated that four (4) additional ‘soft options’ insecticides and one (1) miticide have potential, and registration should continue to be pursued on behalf of the Australian sweet corn industry. These were Movento™ and SCSI-03 (no trade name), which were effective against sucking insects (thrips and aphids); Belt™ and Coragen™, which were very effective against helicoverpa and Sorghum Head Caterpillar; and Paramite™, which suppressed 2-spotted mite populations. These new insecticides and miticide appeared to have low impacts on beneficial arthropods and potentially had a very good “IPM Fit”.

Naturally occurring beneficials (natural enemies) continued to have important regulatory impacts on helicoverpa, aphids and mites, especially in tropical and sub-tropical production systems. It was expected that natural enemies were likely to be more prevalent and therefore more effective, when these additional 'softer’ insecticides were available and incorporated into IPM systems.

The impact from disease infestations on sweet corn production was quite low, a reflection on how well variety selection had been adopted by growers in implementing their IPM systems. It also reflected how well breeding programs were able to incorporate resistance to several diseases common in Australia which, particularly in the temperate areas of the country, all but removed the necessity to apply fungicides. It also reflects the fact that all production districts were affected by varying levels of drought for many years.