National strawberry varietal improvement program - subtropical regions (BS09013)

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note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.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

Strawberries were a delightful dessert fruit that in Australia was produced in the subtropics from late autumn through early spring and in temperate areas during the remainder of the year. The subtropical industry was valued at $160m and focused in Queensland. Previous breeding programs and associated introductions had been pivotal in building an efficient runner supply with increased choices available to fruit growers, because all runner growers strived to produce high quality planting material. The breeding program was designed to produce cultivars which comprised ~ 15 per cent of subtropical production with improved production characteristics to reduce costs and high consumer satisfaction to increase demand. The program was guided by the national industry’s Strawberry Breeding Steering Committee.

The two promising cultivars released in this project were ‘Suncoast Delight’ and ‘Aussiegem’. They had predicted ‘whole of industry’ gross margin increases of 10 and 31 per cent respectively – (when the latter was planted at higher density [54000plants per ha]). These complement six earlier releases, including ‘DPI Rubygem’, which together occupied 14.6 per cent of the low chill runners planted in Queensland at the time and contribute ~ $40 m per year to industry i.e. about $280 m over the last 7 years. A breeding line with very high anthocyanin levels was identified and may have been offered future potential to target health benefits and ‘high-health lifestyle’ markets.

A number of environmental and genetic factors influenced the productivity of strawberry. Productivity could be described as: Y = fn (n, r, x, w, t, a). Where Y = yield of fruit per ha (in kg); n = number of crowns per unit area; r = number of trusses per crown; x = number of berries per truss per time; w = mean berry weight (in kg); t = duration of cropping; a = area.

‘Festival’ was resistant to Fusarium wilt. Inheritance studies indicated that selection for resistance was achievable. Fusarium resistance screening began being routinely implemented in the selection process.

Routine DNA cultivar verification was effective and became incorporated into the breeding program.

The researcher raised the level quantitative genetic breeding techniques in the program, and better integrated this with economic outcomes through a modified gross margin spreadsheet. This showed a relationship between fruit production and price. National data was helpful to develop a more ‘manufacturing ‘approach to production.

The industry had early access to overseas cultivars e.g. ‘Fortuna’ because of linkages, collaborations and systems developed through the DAFF Qld breeding program. High quality cultivars were available in a range of supply streams so growers could better match runner supply with individual farm needs.