This is a final research report from Hort Innovation’s historical archives. Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.

What was it all about?

This study tour involved the President of the Australian Custard Apple Growers Association (ACAGA) and a technical adviser travelling to Thailand from the 28th October to the 3rd November 2007 to view production and handling systems for custard apple (particularly in the Pak Chong area where about 10 000 acres of custard apples were grown at the time). Negotiations to access new improved germplasm from a Thai breeding program were conducted with Professor Chalonchai Babpraserth and Phacharavadee Paerattakul (Director, International Affairs Division) Kasetsart University.

In addition, time was spent with Chalermchai WONGS-AREE, Ph.D (Assistant Professor, Plant Molecular and Cell Biologist) and Sirichai Kanlayanarat, Ph.D (Associate Dean for Research Affairs) at the Prince Mongkut University. Discussions were had with the Prince Mongkut University post-harvest researchers investigating the latest results of custard apple post-harvest research and inspecting facilities and equipment at the University.

Two aspects of the Australian custard apple industry strategic plan which were seen as very important were in developing precocious and heavy natural setting varieties and developing dwarfing less vigorous rootstock. There was one Thai variety that produced large fruit, and set naturally, and may have been well suited to warmer growing districts in Queensland. The study tour provided the opportunity for negotiations on a face to face basis to access this fruiting variety. Although an agreement was not reached on this variety, negotiations continued.

The trip also provided the opportunity to acquire seeds of the Noi Nung (Annona squamosa) variety which met the criteria of disease resistance dwarfing rootstock.

All necessary AQIS permits, inspections and approvals were addressed correctly and seeds were imported.