Evaluating dried grapes types for the Australian industry (DG12004)

What was it all about?

This project, which ran between 2012 and 2016, aimed to identify breeding lines of grapes with superior qualities for drying. It built directly on previous CSIRO breeding projects, which propagated a number of promising varieties.

Dominant varieties of sultana pose challenges for growers including production and quality losses from rain damage at harvest, mouldy fruit and inconsistent production due to variable fruitfulness and biennial bearing.

The aim of these projects was to find breeding lines of sultana types that are less susceptible to these production problems.

In all, some 1,700 single vine seedlings, seven promising selections established on a grower site and 360 promising selections propagated in multiplied plots were assessed, under semi-commercial conditions.

Vines were inspected prior to harvest and dried grapes were sampled. Researchers culled samples with any undesirable characteristics, such as late ripening types, rain intolerance, uneven berry size, poor colour and those damaged easily during harvest.

A total of 36 selections that met all criteria were identified from the trials. They covered a spectrum of harvest dates.

Four of these selections were targeted for evaluation under semi-commercial conditions on grower properties and inclusion in a Plant Breeders Rights (PBR) comparator trial to establish distinctness, uniformity and stability.

A further 13 larger berried selections were also identified with potential to extend the product range of light types available.

Release of one or more of these selections as varieties for industry adoption will enable growers to not only achieve high fruit quality and productivity, but minimize risks associated with rain damage and poor drying conditions associated with unfavourable climatic events.

In addition, 16 small berried types suited to light coloured dried grape production and 13 black selections covering a range in berry size, ranging from small currant types up to the size of raisins were selected. These were to be retained by CSIRO for future research purposes and be available for industry adoption if there is increased market demand for such products.

The results of the project will help the Australian dried vine fruits industry face future production challenges.