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Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.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?

The Australian apple industry had worked hard in the previous decades before this report was published to reduce its reliance on synthetic agricultural chemicals to control pests and diseases. Apple scab, caused by Venturia inaequalis, was the major fungal disease of apples in Australia, and new apple varieties resistant to scab were developed by the Department of Primary Industries and Fisheries, Queensland (DPI&F).

One of these varieties was ‘RS103-130’, which would soon be available to Australian apple growers and help meet consumer demands for healthy food products grown using reduced agricultural chemicals. ‘RS103-130’ was a red apple that had exceptional shelf-life, and was juicy with a sweet, low-acid and mild flavour.

This project identified world’s best practice strategies to successfully grow ‘RS103-130’ apples in the Stanthorpe district of southern Queensland, in both organic and conventional production systems. The spring and summer rainfall in this locality made it a high risk environment for apple scab infection, and the application of fewer sprays for apple scab control had both economic and environmental benefits. The total absence of apple scab symptoms on leaves or fruit of ‘RS103-130’ over four years suggested this variety was ideally suited to other apple producing regions of Australia, which contended with fewer environmental, pest and disease problems.

Australia’s first commercial crop of organically grown ‘RS103-130’ apples was produced in March 2006, as part of this project. Some of these apples were marketed through an organic wholesaler in Sydney, receiving an average price of $37 for first grade and $32 for second grade fruit per 12 kg two-layer carton. Returns in 2007 were even higher, and up to $60 per 12 kg two-layer carton.

The scab-resistant apples, including ‘RS103-130’, were well-adapted to modern high density systems (upwards of 2000 trees per hectare) planted on dwarfing rootstocks. To date, the yield and quality of apples from young trees in such intensive systems had been excellent, with ‘RS103-130’ apples averaging 200 g or higher.

The availability of a new, high quality scab-resistant apple variety at the organic retail level not only offered more choice to the organic apple consumer, but provided orchardists with the opportunity to produce organic apples more easily than if growing the standard varieties available at the time. In addition, ‘RS103-130’ had shown it was a suitable apple for conventional production, rating highly in consumer evaluations.

The potential effects of soil management strategies and mulches on soil health, water use efficiency and managing drought required further investigation, and was applicable to both organic and conventional systems of apple production.

The challenge of organically producing commercial quantities of new scab-resistant apples in the demanding environment (summer rainfall, high pest and disease pressure, poor soils) of the Granite Belt had been met. From this work, a practical manual had been written which provided detailed world class strategies for successful organic production of scab-resistant apples in Australia.