Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

First report of Phytophthora megasperma associated with decline and death of common walnut trees in Italy.

Abstract

In the summer of 2010, several declining trees were present in waterlogged area of a walnut orchard located in the Veneto region. Symptoms included sparse foliage, wilting and shoot and branch dieback. By the next year, a larger area of approximately 1.0 ha with 20% of dead trees was present. The causal pathogen wa identified as Phytophthora megasperma based on morphological, genetic (ITS) and pathogenicity tests. This is thought to be the first report of Phytophthora decline on common walnut in Italy caused by P. megasperma.