Ef fects of Foliar Application of Nano-Hydroxyapatite on Fruit Quality in Cucumis melo L.

Abstract

With the growing global population, improving the ef ficiency and sustainability of agricultural practices through modern technologies, including nanotechnology, is essential. This study evaluated the ef fects of foliar nano-hydroxyapatite (nHAp; Ca₁₀(PO₄)₆(OH)₂) on yield, fruit quality, and mineral composition of melon (Cucumis melo L., var. Cruiser) under field conditions at Universidad Autónoma Agraria Antonio Narro, Torreón, Coahuila, México. Treatments consisted of 0 (control), 2000, 4000, and 6000 mg L⁻¹ nHAp applied as foliar sprays. The experiment followed a randomized complete block design with five beds (R1–R5), and 3–6 fruits per plot were subsampled for total soluble solids and firmness, with plot means used for analysis. Foliar nHAp significantly increased total soluble solids and firmness compared to the control, with the highest values at 4000 mg L⁻¹ (13.27 vs 8.80 °Brix; 2.55 vs 1.44 N). Yield was not af fected by treatments; however, mean fruit weight and fruit diameters dif fered among treatments. Mineral composition was analyzed on freeze-dried composite samples (dry-matter basis) from three blocks (R1, R3, and R5). Potassium content dif fered among treatments, whereas Ca, P, Mg, Zn, Fe, Cu, and Mn remained unchanged. Overall, foliar nHAp improved sweetness and firmness without af fecting yield or most mineral components, with potassium showing a treatment response at 2000 mg L⁻¹.