Abstract

Prunus persica L. Batsch is a high-value cultivar, which is valued due to its high-quality fruit, early fruit harvest, and great commercialization. In this article, the usage of zinc oxide (ZnO) and boron trioxide (B₂O₃) nanoparticles on the plants' growth, yield, and fruit quality of Florida Prince peach trees was investigated under semi-arid field conditions at Rashidiya, Baghdad, during the 2022 and 2023 growing seasons. The experiment was conducted on nine-year-old trees grafted onto Shar rootstock. Seven treatments were established, comprising three concentrations each of ZnO (250, 500, and 1000 ppm) and B₂O₃ nanoparticles (250, 500, and 1000 ppm), along with an untreated control. Spraying ZnO nanoparticles, particularly at 1000 ppm, markedly enhanced shoot length, number of leaves, and leaf area compared with the control. Combined application of ZnO and B₂O₃ reduced fruit drop, improved fruit set, and substantially increased yield per tree relative to untreated plants. Application of nanofertilizers also improved the physical characteristics of fruits, including their weight, size, firmness, and coloration. Spraying boron nanoparticles at 1000 ppm resulted in the lowest titratable acidity and the highest total soluble solids, while zinc nanoparticles at the same concentration significantly increased vitamin C content. Overall, the optimal usage of zinc and boron nanoparticles at appropriate concentrations and timing produced a synergistic improvement in vegetative vigor, productivity, and fruit quality of Florida Prince peach trees grown on calcareous soils under semi-arid climatic conditions. These findings show that nano-fertilization could be a possible and effective measure to enhance the efficiency of nutrients and fruitfulness of peach orchards.