Diagnoses of pear decline and rootstock identification in young pear orchards
AuthorsP. B. Catlin
A. A. Millecan
Authors AffiliationsP. B. Catlin is Associate Pomologist, Department of Pomology, University of California, Davis; A. A. Millecan is Plant Pathologist, California Department of Agriculture.
Hilgardia 21(7):10-11. DOI:10.3733/ca.v021n07p10. July 1967.
Pear decline has occurred predominantly with rootstocks of two oriental species, Pyrus serotina and P. ussuriensis, although there have been reports of tree losses with P. communis rootstocks. Most of the latter have been of the “old” French type imported from Europe prior to 1918. While decline has occasionally been suspected with additional types of P. communis rootstocks (domestic French), generally this species has been tolerant to decline. Although certain seedlings of P. communis have frequently been referred to as resistant or immune, some uncertainty now prevails regarding such resistance. Diagnosis of decline often has been made without microscopic examination of bud unions, and even when bud unions have been examined for phloem abnormalities, the identity of the rootstock may be open to question.
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Seed contamination in transmission of halo blight in beans
Inducing abscission of olive fruits by spraying with ascorbic acid and iodoacetic acid
Chemical identification of pear species used as rootstocks
Light traps as detection devices for moths of cabbage looper and bollworm
Dual-use return-water irrigation system
Effects of 2,4-D and related substances on fruit-drop, yield, size, and quality of Washington Navel oranges