tThis study was carried out to assess the effects of the foliar application of nano-fertilizers of zinc (Zn)and boron (B) on pomegranate (Punica granatum cv. Ardestani) fruit yield and quality. A factorial exper-iment was conducted based on a completely randomized block design, with nine treatments and fourreplications per treatment. Foliar sprays of nano-Zn chelate fertiliser at three concentrations (0, 60 and120 mg Zn L−1) and nano-B chelate fertiliser (0, 3.25 and 6.5 mg B L−1) were applied as a single spray beforefull bloom at a rate of 5.3 L tree−1. The application of Zn and B increased the leaf concentrations of bothmicroelements in August, reflecting the improvements in tree nutrient status. A single foliar spray withrelatively low amounts of B or Zn nano-fertilizers (34 mg B tree−1or 636 mg Zn tree−1, respectively) ledto increases in pomegranate fruit yield, and this was mainly due to increases in the number of fruits pertree. The effect was not as large with Zn as with B. Fertilization with the highest of the two doses led tosignificant improvements in fruit quality, including 4.4–7.6% increases in TSS, 9.5–29.1% decreases in TA,20.6–46.1% increases in maturity index and 0.28–0.62 pH unit increases in juice pH, whereas physicalfruit characteristics were unaffected. Changes in total sugars and total phenolic compounds were onlyminor, whereas the antioxidant activity and total anthocyanins were unaffected.

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