Bacterial canker caused by Clavibacter michiganensis subsp. michiganensis (Cmm) is a threat to tomato crops globally, causing significant crop losses from wilting, fruit lesions and plant death.

This TomatoesNZ-A Lighter Touch project will evaluate the efficacy of the biological product Aureo Gold^TM, used for managing Psa in kiwifruit, against bacterial canker in tomatoes.

In New Zealand, Cmm has caused production losses of varying degrees for the past decade in tomato greenhouses. Its impact varies depending on a range of factors, including the crop variety and environmental stresses, and it is known to stay dormant in the greenhouse soil for many years. Once a crop is infected, the only current control measure is creating buffer zones; however, this approach still results in crop losses, ranging from 10% to total destruction. A complicating factor in using buffer zones is plants tend to only show strong identifiable symptoms under summer stress, but are still contagious while asymptomatic.

In evaluating biological control options, the project aims to deliver a sustainable, control option compatible with the greenhouse tomato industry’s integrated pest management (IPM) programme which focuses on the use of biological control agents (BCAs).

If successful, the project would provide a valuable new tool for tomato growers. In addition, assessing Aureo Gold’s efficacy against bacterial diseases other than Psa will generate valuable insights for other ALT stakeholders and may create opportunities to evaluate the product against additional priority diseases.

Read more about the project:

• January 2026: Project to test biological products to manage bacterial disease in tomatoes