Phosphite Research Part 1: Phosphite injection trials in kauri forest

I. Horner, E. Hough, M. Horne

Plant & Food Research

Completed

2017

Five years of field trails looking at the efficacy of injecting juvenile kauri trees with phosphite to slow the onset of the disease and hence reduce disease impact on kauri.

Evidence from forest trials on ‘ricker’ sized kauri trees suggests that trunk injection with phosphite is suppressing the activity of PA within infected trees. Almost all lesions on phosphite treated trees have stopped expanding and appear to have healed. The longevity of treatment efficacy and the required frequency of treatment for long-term control is yet to be determined. The potential phytotoxicity of phosphite remains a concern, and this will have to be monitored carefully so that rates can be optimised.

• Controlling the Disease