New custard apple varieties and enhanced industry productivity

Abstract

The objectives of CU16002 were to successfully develop new high-yielding green and red skin custard apple selections, evaluate the performance of clonal and seedling rootstock selections and increase grower awareness and knowledge of a range of production issues through a series of industry development field days and workshops.

This project built on the previous project phase (CU13001) to develop new green and red skin high yielding custard apple varieties and clonal and seedling rootstock selections.

Over 2000 hybrid progeny were established during the project term using red and pink skin parents. Approximately 1800 hybrid seedlings were evaluated for tree and fruit characteristics, resulting in over 40 new selections being identified for further evaluation.

A series of trials evaluating new elite selections from the breeding program were established in the previous project phase. Evaluation of these selections in major production regions has resulted in 3 green skin selections being recommended for commercialisation. Two promising red skin selections have also performed well in trials, however further evaluation will be required before they are progressed to commercialisation. Rootstock trials have evaluated a range of seedling and clonal rootstocks and recommendations have
been developed on their suitability to different growing regions.

A small clonal propagation program with a collaborating nursery in North Queensland has successfully produced rootstock of cherimoya and DAF selection 450. Strike rates of over 75% in selection 450 means commercial quantities of this rootstock will become available for industry as the program progresses. Although high strike rates were also reported in cherimoya rootstocks the growth habit of the tree was not ideal for grafting.

All R&D aspects of project CU16002 have been extended to growers and stakeholders through industry field days and meetings, newsletter articles and social media.