What was it all about?

This project, which ran from 2014 to 2017, sought to find out if two treatments, mandipropamid and potassium silicate, reduce Phytophthora root rot in avocados.

Researchers ran laboratory trials of mandipropamid as well as glasshouse trials where it was compared to standard treatment, granular metalaxyl.

Potassium silicate (Agsil drench, spray and injection) was evaluated in field trials to seek evidence of effectiveness against Phytophthora root rot in avocados.   

The key findings were…

• Mandipropamid showed promise as an effective tool in the management of Phytophthora
• Agsil drench application boosted yields and fruit quality, potentially improving net return by 20 per cent or more
• An improved use pattern for metalaxyl was developed, resulting in increased productivity.

The team recommended further field trials to evaluate efficacy of mandipropamid and other new chemistries for improving health and productivity of trees declining from severe phytophthora root rot. They also recommended evaluation of Agsil and other available silicon products compared with existing grower standard practice.