Research Question: Does whitewashing plants with Surround kaolin clay cool the plant off compared to unsprayed green plants?
At 3 ft height, the whitewashed and green blackberry leaves were similarly cooler (less accumulated degree-days) than the ambient air temperatures recorded next to the blackberry plants. (See graph and pictures below)
Surround was applied on the 8th and 21st of June and the 1st and 22nd of July to whitewash eight blackberry plots.
The other blackberry plots were untreated and remained green.
Whitewash appearance was lessened by rains that exceeded 0.5 inches on both the 18th and 30th of June and accumulated from the 7th-8th of July at the Dozier Sta-N-Step Berry Farm in Fayetteville, AR (2017).
There was no significant difference between leaf temperatures on blackberry plants whitewashed with Surround kaolin clay or unsprayed (green).
Dr. Donn T. Johnson
Department of Entomology
University of Arkansas