Projections for winter temperatures in California will likely require many growers to consider tools to address issues with chill accumulation. Research Director at the MARI Agricultural Research Institute, Masood Khezri has been involved in a two-year replicated research trial looking at rest-breaking materials in pistachio production. These types of materials, Khezri noted, could become increasingly valuable for growers now and into the future.
“We are actually anticipating more warm winters in the next 30 years based on the predicted weather data. However, replacing the current Kerman and Peters pistachio trees with lower chill varieties like Golden Hills or Lost Hills isn’t a straightforward solution for many California growers,” Khezri explained. “To address this, we need to enhance our understanding of rest-breaking agents, particularly Dormex.”
Being a relatively new tool for the California pistachio industry, Khezri said growers will want to have a good understanding of its potential. Through two years of st,udy, Dormex has shown to advance bloom in pistachio trees in both low and adequate chill winters. Applications at the right timing were also shown to have positive results regardless of the bearing cycle of the trees. “Data showed that in marginal to low chill years or location, Dormex application in the right timing could increase the yield significantly compared to control, non-sprayed trees,” Khezri explained.
Information from the UC Davis Chill Calculator shows that as of February 5, the Shafter CIMIS station has logged 47.9 portions under the dynamic model, with 678 hours below 45°F. The station in Fine Points has registered 51.1 portions, with 681 hours. There have been 832 hours in Merced, with 51.2 cumulative portions. In Manteca, there have been 632 chill hours, equating to 53.1 portions, Finally, the CIMIS station in Durham has registered 57.4 portions, with 763 hours.
Listen to the segment below.