Nutritional Evaluation of Newly Established Peach (Prunus persica) Orchard in the Southeastern USA

Abstract

Peach production in the southeastern United States faces increasing challenges due to climate variability, complex soil profiles, and evolving orchard management practices. This thesis evaluates the nutritional dynamics, physiological responses, and vegetative development of young peach trees in a newly established orchard in central Alabama. Three commercial cultivars: ‘Augustprince’, ‘Fireprince’, and ‘Rubyprince’ were grafted onto two rootstocks (‘Guardian®’ and ‘MP-29’) and subjected to varied fertilization rates (25%, 50%, and 100%) and irrigation regimes (irrigated vs. non-irrigated) across two growing seasons (2023–2024). Physiological measurements, including stomatal conductance, photosynthetic assimilation, and chlorophyll content, were paired with growth metrics such as trunk cross-sectional area, tree height, shoot length, bud, and node count. Foliar and pruned wood nutrient content were analyzed to quantify nutrient accumulation and removal across treatments. Soil and nematode profiling ensured experimental integrity by ruling out confounding stressors. Principal Component Analysis revealed clustering based on rootstock performance and irrigation status, with potassium and magnesium contributing significantly to treatment differentiation. Results showed that irrigation consistently enhanced growth and physiological performance, especially in late-season cultivars during periods of drought. ‘Augustprince’ demonstrated superior shoot length, node count, and nutrient uptake, highlighting its resilience and suitability for southeastern conditions. Notably, trees receiving 50% of the recommended fertilizer rate performed comparably to those receiving full rates, suggesting opportunities to reduce input costs and environmental risk without compromising early tree vigor. These results are preliminary. Subsequent evaluations of fruit yield and quality are planned to validate and strengthen the conclusions.