Movement of Foliar Applied Boron out of Leaves and Accumulation in Flower Buds and Flower Parts of ‘Italian’ Prune

Abstract

Abstract To study the distribution of foliar applied B in ‘Italian’ prune ( Prunus domestica L.) trees, 500 ppm B solutions were applied in July, September, and October. Boron applied in September or October moved readily out of senescing leaves and apparently into adjacent flower buds and subtending tissues. Boron applied in mid summer (29 July) moved out of nonsenescing leaves at a similar rate. Flower buds accumulated B slowly in the fall and winter, but rapidly during bud swelling. In flowers, the largest increases in B concentrations due to foliar sprays were in anthers (248%) and styles (162%).