Endogenous abscisic Acid in relation to bud growth in alternate bearing ;valencia' orange.
An investigation was conducted into the relation of ABA (cis-trans-abscisic acid) in the dormant buds of alternate bearing ;Valencia' orange (Citrus sinensis [L.] Osbeck) trees. ABA did not appear to be related to alternate bearing but t-ABA (2-transabscisic acid) did. There was 5- to 10-fold more t-ABA than ABA in the buds. There was more t-ABA in the buds of the "on" trees than in the buds of the "off" trees, and a drastic drop in t-ABA in both types of buds as spring growth approached. Bud dormancy and readiness for growth as related to t-ABA are discussed.
Jones
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WW
Department of Plant Sciences, University of California, Riverside, California 92502.
Coggins
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CW
Embleton
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TW