Short-term boron deficiency in a black spruce (Picea mariana [Mill.] B.S.P.) plantation

摘要: Abstract Boron deficiency was suspected as the immediate cause of abnormal needle loss which occurred in black spruce (Picea mariana [Mill.] B.S.P.) plantations northwestern New Brunswick during successive years below normal precipitation. An experiment subsequently conducted a 21-year-old plantation, involving foliar application B, singly or combination with broadcast N treatment. Current-year control foliage exhibited about 6 mg B kg−1 at end first growing season marked by below-normal Foliar application, after emergence new foliage, raised concentration to 24 mg kg−1 and resulted significantly increased mean mass. The growth response diminished rose trees 10 mg kg−1 increasing precipitation, no effect on radial detected. Addition both significant mass basal area responses, but there were B–N interactions. It is suggested that plantation suffered mild beginning experiment, relieved above 8 mg kg−1 moderate severe levels deficiency, accompanied excessive loss, would have developed had moisture deficit lasted through more than 1 year dropped 5 mg kg−1.