Osmolyte Regulation as an Avocado Crop Management Strategy for Improving Productivity Under High Temperatures

Abstract

Climate change worsens abiotic stresses, primarily due to high temperatures, which have a negative impact on avocado productivity, leading to reduced crop yields, affecting fruit set and abscission. To tackle these challenges, antioxidants such as glycine, choline, and proline can enhance plant tolerance to these stressors and minimize plant cell damage. This work aimed to use these antioxidants to improve avocado commercial yield and quality under challenging environmental conditions. This study was conducted at the experimental farm of the Polytechnic University of Valencia, Spain, to evaluate the effects of glycine, choline, and proline on ‘Hass’ Persea americana plants. The research took place during the 2022–2023 and 2023–2024 seasons in a 2.0 ha orchard, using a randomized design with two treatments: one with antioxidants and the other without. Substances were applied at specific phenological phases, as the BBCH code indicated. Tree growth parameters, including trunk diameter, height, crown diameter, and tree canopy volume, were measured using geometric formulas. Leaf samples were collected to analyze the nutrient concentrations of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn using atomic emission spectrometry. Marketable fruit yield and quality parameters such as fat, fiber, and protein content were evaluated using the Association of Official Agricultural Chemists (AOAC) methods. The results showed that antioxidants did not significantly affect tree growth but altered leaf mineral nutrient composition. N and P concentrations were reduced, while K and Ca concentrations were increased. Mn and Zn levels were higher in the treated plants, whereas Cu levels were higher in the control plants. Productivity significantly improved, with a 49% increase in fruit yield, larger fruit size, and a 7% increase in fat content, though fiber and protein remained unchanged. These results show the selective benefits of antioxidants in optimizing avocado yield and quality under stress.

Keywords

• choline
• glycine
• plant nutrition
• <i>Persea americana</i>
• productivity
• proline