An observational comparative study of Hass avocado fruit quality and its associations with rhizosphere soil properties across four representative orchards in China.

INTRODUCTION: Avocado (Persea americana Mill.) quality is significantly influenced by soil conditions, as well as climatic factors, fertilization regimes, and orchard management practices. However, systematic research on the combined effects of these factors for 'Hass' in China remains limited. METHODS: This observational comparative study compared four producing regions, Menglian (ML), Yuanmou (YM), Xishuangbanna (XSBN), and Longzhou (LZ), by analyzing fruit quality, rhizosphere soil properties, enzyme activities, and mineral elements using standard analytical procedures and multivariate analysis. RESULTS: The results showed distinct regional characteristics: ML fruits were pear-shaped and had the highest edible yield (77.91%); YM produced the largest single fruit weight (194.36 g) and thickest pulp (2.38 cm); XSBN excelled in vitamin C (38.87 mg/100 g) and soluble sugars (4.91%); LZ showed the highest K (6.91 mg/kg) and Ca (81.51 mg/kg). Soil properties also varied significantly. ML soil had the highest Fe, Mn, Cu, and catalase activity; YM soil had the highest pH, K, and alkaline phosphatase; XSBN soil was richest in organic matter and total N; and LZ soil had the highest P and As. DISCUSSION: Exploratory correlation analysis revealed that soil enzyme activities and elements such as Mg, Ca, K, and Mn showed strong associations with fruit size, sugar-acid balance, and nutritional composition. These findings identify key soil factors correlated with avocado quality and provide an exploratory basis for region-specific soil management aimed at production optimization. The regional variation in fruit quality highlights the added value of Chinese-grown Hass avocado as a distinctive regional product.