The translocation and distribution of foliar-applied boron during blooming period of apple trees

The spur leaves of 20-year-old apple trees (CV. Starking/Malus prunifolia Borkh) were applied with H310 BO3 solution (10B 250 μg/g) during blooming period. The results showed that the 10B were transported to the other parts after two days, and the bourse shoot got most of B. The content of 10B in labelled leaves decreased with time and 60% of 10B was transported after 12 days, while the content of 10B in the young fruits and the xylem kept increasing, though 10B content was only about 10∼13 percent of the total B. Within 4 days, 10B content was about 30 percent of the total B in the labelled leaves. When the boron was foliar-applied the symptom of B deficiency was alleviated temporarily