Distribution and transport of foliar applied zinc in pistachio

The distribution and transport of foliar applied Zn were determined for pistachio (Pistachio vera L.) seedlings and mature trees using stable Zn-68 isotope. Tn seedlings, approximate to 5.4 % of Zn adsorbed by the leaf was transported out of the treated leaves and this Zn was detected in all other plant parts to varying extent. In mature trees, the transport of Zn occurred both acropetally and basipetally within the leaflets with more basipetal movement; however, no significant amount of Zn was transported out of the treated leaflets during the first 10 days after application. The total percentage of Zn transported to other plant parts 20 days after application was significantly greater when Zn,vas applied to immature leaflets (6.5%) than to mature leaflets (2.1 %), though the majority of the absorbed Zn remained within the treated leaflets. The limited mobility of foliar-absorbed Zn in pistachio may partially be attributed to the high binding capacity of leaf tissue for Zn.