University of California

Blackline in walnuts: Delayed failure of unions killing many walnut trees in central coastal counties


E. F. Serr

Author Affiliations

E. F. Serr is Pomologist, University of California, Davis.

Publication Information

Hilgardia 13(3):8-9. DOI:10.3733/ca.v013n03p8. March 1959.

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Killing of a narrow strip of cambium and bark at the union of the Persian– Juglans regia–or English, walnut tree top and its rootstock is causing increasing losses of individual trees–even abandonment of entire mature orchards –in the walnut producing areas adjacent to San Francisco Bay.

Serr E. 1959. Blackline in walnuts: Delayed failure of unions killing many walnut trees in central coastal counties. Hilgardia 13(3):8-9. DOI:10.3733/ca.v013n03p8

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Hybrid cotton breeding program: Limited quantity of cotton hybrids produced for scientific use but seed production on commercial scale not yet possible

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Lime-induced chlorosis studied: Physiology of disorder investigated to learn role of malonic acid and possibility of a block in organic acid metabolism

New disease resistant tomatoes: Improved strains of varieties Pearson and Red Top developed in plant breeding program at Davis and released to seedsmen

Walnut aphid investigations: Evaluation of new and old aphicides object of experiments conducted in northern California test plots in 1958 season

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Ammonium bicarbonate toxicity: Root injury occurred from within few hours to several weeks in solution culture tests with citrus, avocado, and soybeans

Use of sorptive dusts on fleas: Control of fleas on cats and dogs achieved by treatment with dusts that are easily applied and nontoxic to pets or people

Migration habits of: The Ladybird Beetle

Effect of Bathyplectes curculionis on the alfalfa-weevil population in lowland middle California

The apparent climatic limitations of the alfalfa weevil in California

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