Project Detail

Project Number

02009

Project Leader

D. Brink

Institution

Hortgro Science

Team Members

-

Student(s)

-

Date Started

September, 2009

Date Completed

September, 2011

Developing a sunburn control strategy for Granny Smith, Fuji and Braeburn using Raynox Plus™

Executive Summary

The objective of the study was to identify cost effective strategies for the use of Raynox Plus™ to control sunburn in ‘Granny Smith,’ ‘Fuji’ and ‘Braeburn’ apples.  Raynox Plus™ was applied according to the label specifications as well at double the prescribe dosage.  The normal as well as double concentration sprays were applied on calendar dates as well as according to weather predictions.

In the 2010 season, Raynox Plus™ significantly reduced sunburn on Braeburn in the Ceres area and on class 2 sunburn on Fuji in the EGVV area. More sprays at the standard concentration seemed to have resulted in less sunburn than doubling the concentration and spraying fewer times.  During the 2011 season, the double concentration spray was replaced by a spray every 14 days (double the number of sprays).  During 2010/2011, no difference was found between applying Raynox Plus™ and the unsprayed control.

Considering the effort and cost involved in applying Raynox Plus™ along with the small reduction in sunburn, not to mention the variable results obtained, Raynox Plus™ does not appear to be an economically viable option to reduce sunburn in apples under South African conditions.

For Final Report, please contact:

anita@hortgro.co.za