What was it all about?

This work continued evaluation of new sweet cherry lines to determine their commercial potential. Lines were developed by the National Cherry Breeding Program in South Australia, which finished in 2014.

Controlled hybridisations were achieved by enclosing the flowers of self-incompatible mother trees inside insect proof nets. Flowers were then individually pollinated by hand at full bloom with pollen collected and stored from selected male self-fertile parents.

Ripe fruit was harvested, seeds removed, cold treated and geminated. Seedlings were then raised in the glasshouse before being grown in a field nursery for one growing season. Trees were observed to determine harvest date, and crop level, average fruit weight, firmness and colour.

Individual trees judged to have met basic minimum standards of fruit size and soundness had a subsample of their fruit crop harvested for further testing. Laboratory assessment measured the quality parameters of fruit diameter, average weight, fruit shape, the amount and type of any damage present, total soluble solids (Brix), flavour profile, eating quality and stem characters, along with a comment on the examiner’s overall perception of the sample. A grade for the particular sample was also determined. All lines from the 2013/14 season were categorised.

After each harvest season, promising lines were grafted onto Mazzard F12.1 rootstocks for internal secondary evaluation requirements and the National Cherry Variety Evaluation Program (NVCEP) was carried out. Bare rooted grafted trees were then made available to be planted the next winter.

Major findings and outcomes were…

• 131 high quality lines were identified, categorised and progressed for evaluation on rootstock
  
  
• A 671 tree evaluation resource was planted and developed to identify lines that have commercial and breeding value on commercial rootstocks
  
  
• Australian cherry growers can fast-track and evaluate small scale semi-commercial plantings of the breeding program’s most advanced material, with six lines suggested as candidates.
  
  
• The Australian Cherry Breeding and Evaluation Business Plan was developed.
  
  
• The breeding program release Sir Douglas performed favourably compared to Stella in local evaluation trials on Mazzard rootstock and has the advantage of being a week earlier in maturity and more crack resistant. Its characteristics are analogous to the popular new variety Blackstar and it may further benefit from a pairing with a precocious rootstock such as Gisela 6.

Significant economic advantage should arise to Australian growers and exporters from the adoption of new sweet cherry varieties with improved fruit quality and cultural characteristics.