Completed project
Building resilience to drupelet disorder on rubus (RB14003)
Publication date: December 12, 2018
Delivery Partner: Tasmanian Institute of Agriculture
This project investigated the causes, mechanisms and potential management strategies for red drupelet reversion in blackberries. Red drupelet reversion is a disorder of blackberries where drupelets that are black revert to red, usually after the fruit has been harvested and placed into cool storage. This reduces both the visual and physical quality of the fruit.
The project ran from 2015 to 2019 and involved laboratory trials that investigated the underlying physical and chemical changes associated with the disorder, and then field trials that assessed the effects of nitrogen application rate, harvest technique, environmental conditions at harvest and postharvest storage conditions on the incidence and severity of the reversion.
From the laboratory trials, the project found that colour change is caused by a decrease in anthocyanin concentration (the compound that pigments food with red/purple/blue colouring), reduced cellular integrity, reduced drupelet firmness and lower pH levels. The researchers found that susceptibility to the reversion disorder is influenced by genetics, with evidence that cultivar firmness, cell wall formation and susceptibility to post-harvest weight loss can influence incidence and severity of reversion.
The field trials then confirmed that stresses, such as warm temperatures during harvest, are linked to high rates of red drupelet reversion, being linked to an increase in the mechanical injuries incurred during harvest and handling. The project team also found that an increase in drupelet reversion can also be caused by excessively high nitrogen application rates and rapid temperature changes in postharvest storage.
The project made the following recommendations for growers:
For the industry as a whole, the researchers suggested that development of varieties with low susceptibility to red drupelet disorder should be pursued as skin firmness, texture and water loss are correlated with susceptibility to the disorder.
Read the fact sheet produced by the project team that summarises the main findings.
Related industries
This project was a strategic levy investment in the Hort Innovation Raspberry and Blackberry Fund
© 2026 Horticulture Innovation Australia Limited.
