When the weather gets hot, apples might need sunscreen too
Climate change is causing hotter, drier summers in British Columbia’s Okanagan Valley. Tree fruit producers need tools to protect their crops from sunburn.
In late June 2021, hot air temperatures broke records across the Okanagan Valley and caused major crop losses due to sunburn and heat damage. A preliminary trial was being conducted that summer in a Fuji apple orchard.
The aim of the trial was to test a “sunscreen” or foliar spray that can be sprayed onto apple fruit and leaves. This “sunscreen” is made from finely ground calcium carbonate (chalk) and can be applied with commonly available spray equipment.
Read this paper on the Canadian Journal of Plant Science website.
Three applications of the spray reduced severe sunburn by 9 percent and prevented the growth of lopsided fruit, which occurs when apples are exposed to hot temperatures. This “sunscreen” had no other effects on fruit quality.
“Sunscreens” like the one tested in this trial may be useful to help farmers protect their crop from sun and heat damage, but more work is needed to figure out when and how often they need to be applied.
Read the paper — “Tools for climate resilience in tree fruit II: A calcium carbonate-based foliar spray showed potential for protecting fruit quality during an unprecedented heat event” by Kirsten Danielle Hannam and Jesse Lance MacDonald.
