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Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.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?

This project was established to ensure continued access by Australian mushroom growers to products that would assist them to sustainably manage pest and disease problems.

A total of three efficacy growing room studies were completed between July 2009 and December 2009; laboratory efficacy work evaluating imazalil (Magnate 750 WSG®) as a spawn treatment against Trichoderma green mould was completed by March 2010. These included two efficacy trials for abamectin (Wizard 18®)against red pepper mites and one trial for Mn prochloraz against cobweb disease. There was one laboratory efficacy study against green mould caused by Trichoderma aggressivum (Th4) and T. atroviride (Th3) using a granular formulation of imazalil.

The efficacy study for the fungicide Mn prochloraz (Octave®) against cobweb disease evaluated three different use patterns; incorporated into the casing at the full rate, at half rate, followed by watering on half rate after the first flush as a split application and finally as a watering on split application, the first application at fresh air, the second after the first flush. Both split applications were the most effective in managing the cobweb disease, with greater incidence of the disease in third flush mushrooms with a single treatment at casing.

Abamectin was selected as a low toxicity alternative for the organophosphate insecticide diazinon. Five residue trials were completed, all necessary residue samples collected and residue analyses undertaken. Preliminary laboratory efficacy work established that abamectin was very active against mushroom mites and this was confirmed in two growing room efficacy studies.

The fungicide imazalil (Magnate750WSG®) was evaluated using a petri dish bioassay as a treatment against green mould, Th4 and Th3. As expected, the Th4 was not controlled by the benzimidazole fungicides, but was by imazalil. Th3 was controlled by all the fungicide treatments, but imazalil was the most effective.

All relevant data, including growing room reports, residue analyses, efficacy data, etc., had been sent to Kevin Bodnaruk (AKC Consulting) for him to prepare submissions to APVMA for permit/registration so that the chemicals covered in this report may be given approval for use on mushrooms.

The implications of this work for the Australian mushroom industry were discussed. This project was on-going in terms of legislative requirements, availability of existing products, management of new and existing pesticide resistance issues and development of new pesticide chemistry, including organic products.