RELATIONSHIPS BETWEEN LEAF AND SOIL BORON AND BORON TOXICITY OF PEACHES IN BRITISH COLUMBIA

Abstract

Soil and leaf boron were determined in British Columbia peach orchards exhibiting a range of B concentration, including suspected toxicity. B toxicity always occurred when leaf concentration in May exceeded 130 mg/kg, and frequently occurred when leaf B concentration in July was between 50 and 83 mg/kg. Revised leaf standards were suggested to indicate a desirable range of 26–50 mg/kg leaf B in July. Leaf and soil B for peaches were generally correlated. Exceptions occurred when soil B was concentrated near the soil surface or deep in the soil profile. Leaf B in July was from 26 to 50 mg/kg when soil B to a 90-cm depth ranged from 0.2 to 0.4 mg/L of soil. Key words: Boron toxicity, leaf and soil B, peaches