Project Detail
Project Number
PL 02-10
Project Leader
A. de Kock
Institution
ExperiCo Agri-Research Solutions
Team Members
-
Student(s)
-
Date Started
December, 2009
Date Completed
June, 2011
Effect of alternative application methods of Iprodione for post-harvest control of Botrytis decay on plums
Executive Summary
- In 2010 the quantitative spray coverage was significantly better on Laetitia plums treated with an ESS atomiser compared to a standard atomiser. This coincided with Iprodione residues of more than double the permissible residue limit.
- The ESS nozzles were adjusted for Southern Belle plums and the quantitative spray cover was less than on fruit treated with the standard atomiser. However, Iprodione residue levels and decay control on fruit treated with the two atomiser types were similar.
- Due to the fact that decay control was not improved with the ESS atomiser, a high volume spray was tested in 2011. The quantitative spray deposit was significantly less on fruit treated with a standard atomiser compared to fruit treated with a high volume spray. However, residues were significantly higher on fruit treated with a standard atomiser, compared to a high volume spray, probably due to the difference in Iprodione concentration.
- With the high volume spray, exposure time did not affect quantitative spray deposit, but with the standard atomiser, spray deposit increased with an increase in exposure time.
- On Laetitia and Southern Belle plums, Botrytis decay incidence and severity was significantly higher for fruit treated with the standard atomiser compared to a high volume spray, despite higher residues of Iprodione.
- With the high volume spray treatments, there was no difference in decay control between 20 and 30 second exposure times, indicating that a exposure time of 20 seconds is sufficient for effective decay control. With a 10 second exposure time decay incidence tended to be higher compared to the longer exposure times.
For Final Report, please contact:
anita@hortgro.co.za