Abstract

Boron has been correlated with fruit set and productivity, and as consequence commercial orchards carry out foliar applications at different seasonal plant stages. A cherry tree experiment located in the central valley of Chile was carried out to identify the absorption and movement of foliar B applications, applied before bud break, to other organs. Boron application consisted in treating Cherry buds with B solution enriched boric acid with the stable isotope 10 B. An aliquot (5 µL) of 10 B was applied with a micropipette to the surface of the buds in August (southern hemisphere) in five trees as replicates. Ninety days after the 10 B application, leaves of the spur, wood of the spur base, wood between spurs and fruits were collected, dried at 65°C, digested in a microwave (CEM-Mars 5) and extracts analyzed for isotopic determinations using an ICP-MS (7500 Series, Agilent). Results indicated that 10 B applied on surface of buds was absorbed and retained primarily in fruit tissues, and in a less extent on leaves and wood between spurs. An appreciable amount of 10 B was also detected in the wood of the spurs base. At the same 10 B application time, additional bud samples were collected and observed using an electron microscopy (SEM) to determine tissues morphology showing the presence of scales, trichomes and spaces on the buds where absorption could occur. Further studies are needed to better understand boron movements within Cherry tree buds