University of California

Pear decline research


W. H. Griggs
K. Ryugo
R. S. Bethell
K. Uriu

Authors Affiliations

W. H. Griggs is Professor of Pomology, University of California, Davis; K. Ryugo is Assistant Pomologist, U. C., Davis; R. S. Bethell is Farm Advisor, El Dorado County; K. Uriu is Assistant Pomologist, U. C., Davis.

Publication Information

Hilgardia 16(6):9-10. DOI:10.3733/ca.v016n06p9. June 1962.

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High summer temperatures appear to be an important contributing factor—in combination with psylla feeding—adding to tree losses from pear decline. Thus far, none of the sprays, ground applications, injections, or scoring treatments have had any discernible effect on the progress of pear decline. None of the treated or control trees improved, a few apparently held their own, but most have deteriorated.

Griggs W, Ryugo K, Bethell R, Uriu K. 1962. Pear decline research. Hilgardia 16(6):9-10. DOI:10.3733/ca.v016n06p9
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