University of California

Whitewash found harmless in applications on walnut leaves


J. H. Foott
D. R. Heinicke

Authors Affiliations

J. H. Foott is Farm Advisor, Salt Luis Obispo County, University of California, Agricultural Extension Service; D. R. Heinicke is Pomologist, Canada Department of Agriculture (developer of the CO airstreams measuring device used in these tests).

Publication Information

Hilgardia 21(3):2-3. DOI:10.3733/ca.v021n03p2b. March 1967.

PDF of full article, Cite this article


Whitewash applied to the leaves of Persian walnut trees of the Payne variety showed no injury to the leaf and did not interfere with photosynthesis. There was no significant effect on total yield in the whitewash tests, but the percentage of larger, sound nuts increased. These studies also indicated that temperatures above 90°F were very detrimental to photosynthesis and temperatures of 95°F or above stopped it completely.

Foott J, Heinicke D. 1967. Whitewash found harmless in applications on walnut leaves. Hilgardia 21(3):2-3. DOI:10.3733/ca.v021n03p2b
Webmaster Email: wsuckow@ucanr.edu