The aim of the study was to examine response of ‘Jersey’ highbush blueberry to boron (B) fertilization. The experiment was carried out in 2002-2003 at a private plantation in Central Poland on mature blueberries planted on a sandy loam soil with pH 4.1, low organic matter status, and medium available B content. Blueberries were supplied with B by foliar applications or broadcasting. Foliar B sprays were done in the spring or the fall. Spring B sprays were performed at the beginning of blooming, at petal fall, and 3 and 6 weeks after the ending of flowering. In each spring spray treatment, B was used at a rate of 0.2 kg ha^-1. Fall B spray was done 5 weeks after fruit harvest using 0.8 kg B ha^-1. Soil B was applied at the stage of bud break at a rate of 2 kg ha^-1. Blueberries unfertilized with B served as control. The results showed that soil B application and spring B sprays increased B status in flowers and leaves. However, B fertilization, regardless of application mode, had no effect on plant vigor, the number of flowers per cane, fruit set, mean fruit weight, berry firmness, and yielding. Berries of blueberries sprayed with B in the spring had increased soluble solids concentrations. It is concluded that: (i) B fertilizer requirements of ‘Jersey’ highbush blueberry are low, and (ii) at hot water extractable B concentration in a soil below 0.37 mg kg^-1 and/or at B status in leaves of current season shoots below 37 mg kg^-1, spring B sprays should be applied in blueberry culture to increase soluble solids concentration in fruit.

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