Distribution of Phytophthora spp. in Southern Texas Citrus Grove Soils

Abstract

A soil survey was conducted in 61 citrus groves in South Texas to determine the Phytophthora spp. present and their population levels. The survey revealed the presence of Phytophthora in 59 locations, with P. citrophthora in 13 locations, P. nicotianae in 46, and P. palmivora not found. Soil plating assay and PCR was conducted to verify the different Phytophthora spp. We analyzed our data to find sites which showed counts of over 10 to 20 propagules/cm3, a value that is of concern. Accepted for publication 19 July 2016. Published 18 August 2016.