New pear roots for old … inarching decline-immune seedlings into susceptible peas trees
AuthorsR. L. Rackham
B. E. Bearden
R. S. Bethell
R. H. Gripp
G. W. Morehead
J. W. Osgood
Authors AffiliationsRobert L. Rackham was Extension Technologist (Pear Decline) and is now Farm Advisor, Sun Bernardino County; Bruce E. Bearden, Mendocino County; Richard S. Bethell, El Dorado County; Russell H. Gripp, Lake County; Cordon W. Morehead, Sacramento County; Joseph W. Osgood, Placer County are Farm Advisors, Agricultural Extension Service, University of California.
Hilgardia 18(6):12-14. DOI:10.3733/ca.v018n06p12. June 1964.
An agricultural extension project was initiated in the spring of 1962 to determine whether pear trees susceptible to decline could be saved by adding a new nonsusceptible root system around the base of the trees. Although the cause of pear decline was not yet known, it was an established fact that pear trees on Oriental pear and Old French (churn bottom) rootstocks were most susceptible to the disease. Rootstocks produced from Old Home cuttings or Domestic French seedlings grown from a seed source known to be free of Oriental pear pollination were for the most part immune to decline.
Also in this issue:50 years of extension-research
High- and Low-moisture alfalfa wafers for milk production
Soil analysis aids grazing management in Humboldt County
Bulk handling of shipping fruits — trials encouraging in Tulare
Compacted golf greens respond to deep aeration, controlled irrigation: Los Angeles County tests
Compacted golf greens respond to deep aeration, controlled irrigation: San Bernardino County tests
Depletion and accumulation of trace elements in irrigated soils
Nernatocides increase onion yields
Sample manipulation and apparatus useful in estimating surface and penetration residues of DDT in studies with leaves and fruits