Field Evaluation of Trichoderma spp. for Control of Armillaria Root Rot of Peach

Abstract

Management of Armillaria root rot (ARR) of perennial crops is challenging and requires an integrated approach. In this study, Trichoderma asperellum and T. gamsii formulated as Remedier WP were drenched onto peach trees 3 to 12 days after planting (2007), and biannually thereafter in spring and fall for a total of three years in two commercial replant sites of South Carolina. All trees were planted in spots where a tree had declined from ARR the previous season to maximize disease pressure. Tree survival and trunk diameter were determined each year in the control and Remedier WP treatments. Four years after planting (2011), about 50% of all control trees and Remedier WP-treated trees had died from ARR in both locations. There was no statistical significance in survival between the treatments in either location. However, three and four years after planting, surviving Remedier WP-treated trees had significantly larger tree trunks compared to control trees in the Campobello location. Not enough trees survived in the other location for meaningful analysis of tree trunk diameter data. Our results show that in soils with heavy ARR inoculum levels, biannual drenches of Trichoderma spp. formulated as Remedier WP starting at planting are ineffective for ARR control of peach. Accepted for publication 27 October 2011. Published 29 November 2011.