Getting to the Bottom of ‘Bronzing’, A Peach Skin Disorder Causing Severe Losses for Organic and Conventional Peach Growers

Project Overview

Project Type: On-Farm Research
Funds awarded in 2016: $15,000.00
Projected End Date: 03/14/2018
Grant Recipient: Clemson University
Region: Southern
State: South Carolina
Principal Investigator:
Guido Schnabel
Clemson University

Information Products


  • Fruits: peaches


  • Crop Production: crop improvement and selection, tissue analysis
  • Education and Training: extension, on-farm/ranch research

    Proposal abstract:

    We have to understand the cause of bronzing in order to design management strategies. Therefore our foremost objective is to reproduce the symptoms in the field, which has never been done before. Based on previous observations we believe that bronzed areas of the fruit are not caused by outside factors such as insects or pesticide damage. This has been established in preliminary work. Obviously we are dealing with a disorder that is coming from 'inside' the tree. It likely is a physiological disorder related to tree stress due to inappropriate horticultural practices. The field trials will be conducted in orchards that historically had bronzing issues and will be designed to test the hypotheses. The results of this study will be used to make the first ever science-based bronzing management recommendations.

    Project objectives from proposal:

    -survey cultivars for bronzing incidence and fruit for patterns

    -reproduce bronzing symptoms in the field

    -determine the presence or absence of viroids in affected peaches

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.