Ethyl formate fumigation technology – upscaling application towards commercialisation

Ethyl formate fumigation is the most promising alternative to replace methyl bromide fumigation as a postharvest treatment for a wide range of phytosanitary pests. Also, ethyl formate is highly effective against a key phytosanitary pest of South African export fruit, the grain chinch bug, Macchiademus diplopterus, a pest that until now, has been very difficult to control. The aim of this project is to develop technology for large scale fumigation of export fruit using ethyl formate, as opposed to Vapormate® (a formulation of ethyl formate with some challenges for large scale application).

We visited international research centres where other scientists are also working on the development of ethyl formate fumigation technology for postharvest use, to gain insight and knowledge from their experiences and expertise. We have contracted engineers to design and build an ethyl formate dispensing system for application of the fumigant in a modified shipping container.

The research visits provided valuable networking opportunities with relevant postharvest research scientists, and contributed to the design and decision-making around the dispensing system and protocols for fumigation. A nozzle system to introduce liquid ethyl formate into the fumigation space was designed and tested. Effective control of grain chinch bug was achieved using this system.

We have successfully developed a dispensing method for liquid ethyl formate into a shipping container under safe conditions, using a N2 generator and gas sensors (O2 and ethyl formate) to monitor levels throughout the process. We are now in a position to use this system to obtain efficacy data for various insects, conduct fruit quality assessments, and ultimately upscale the system for application in cold room capacity.