In the wake of extreme heat impacting tree fruits in the Okanagan and Similkameen regions, a significant discovery has been made at Summerland's research center by Dr. Hao Xu of Agriculture and Agri-Food Canada. The study highlights the effectiveness of "larger and more vigorous" rootstocks in reducing heat stress in Ambrosia apples. This comes after the 2021 heatwave led to reduced yields and quality in harvested fruits.
Field trials comparing Ambrosia and Gala apples across five different rootstock sizes demonstrated that larger rootstocks could significantly mitigate sunburn damage, a common issue during heatwaves where temperatures soared above 44 degrees Celsius. The research utilized an apple delta absorbance meter for early detection of sunburn browning, underscoring the vulnerability of smaller rootstocks to heat stress due to limited water transport capacity and canopy shading.
Dr. Xu emphasized the potential benefits of larger rootstocks for orchard renovation or renewal, considering the constraints of BC's seedling regulations for orchardists. The research, which necessitates over a decade of evaluation due to the comprehensive analysis of tree growth and yield potential, continues in collaboration with local orchardists to explore additional strategies for fruit cultivation amidst climate change.
The significance of maintaining a robust apple industry for food security, particularly highlighted during COVID-19 shutdowns, was also noted by Dr. Xu. The study, which included contributions from Dr. Suzanne Blatt, Dr. Yoichiro Watanabe, Dr. Kelly Ross, and Dr. Xiaotang Yang, alongside technical support from several others, represents a collaborative effort towards enhancing the resilience of apple production against climatic extremities.
Source: castanet.net