An Effect of Kinetin on the Translocation if 14C-Labelled Photosynthate in Citrus

Abstract

This study indicates that the application of kinetin to a recently formed fruit enhances its ability to import photosynthetic assimilates. Cytokinins are known to influence .the transport of plant metabolites (Letham 1967), and in the case of vine shoots Shindy and Weaver (1967) have recently demonstrated an effect of the kinin 6-(benzylamino)-9-(2-tetrahydropyranyl)-9H-purine on the translocation of 14C_ labelled assimilates. The present paper reports an effect of kinetin (6-furfurylaminopurine) on the accumulation of14C-labelled substrates by citrus fruits (cv. Washington Navel). In such crops the newly formed fruitlet is often unable to compete successfully with adjacent expanding leaves for substrates and this is thought to result in early fruit drop (Haas 1949; Sauer 1954).