TRIALS at a Waikerie pistachio orchard are helping to inform the industry’s future chill management practices. 

The polymer trial for 2024/25 season is being executed in Rob Haynes‘ orchard, in Waikerie, to capture the effects of polymer in chill-deprived locations. 

Waikerie continues to be low in chill accumulation. It is just 53 dynamic chill portions - a calculation based on hourly temperatures – and only 674 hours less than 7C by 31 August 2024. Tinytag temperature/RH sensors maintained in Rob’s orchard were used for chill calculations. 

Polymer was applied in August to September. A total of 240 shoots have been randomly selected, tagged and given unique numbers for observations on phenology, bud burst and flowering, and yield traits – number of bunches, number and weight of nuts – at harvest. Bud burst started from first week of September and flowering around third week of September.  

It is time to record juvenile shoot dieback incidence as it appears in orchards in different locations. Orchards that exhibit juvenile shoot dieback will be visited this year to record details and appropriate orchard management practices for further investigation.  

Dr Maha Mahadevan
Research officer
Pistachio Growers Association