Abstract

Avocado (Persea americana) production is nowadays questioned due to its environmental impact, especially water footprint. Avocado rootstocks have been developed to enhance the resistance to environmental conditions but not for resource efficiency. In this study, physiological parameters of vegetative (clonal) propagated (Dusa®) and seed propagated (Mexicola) rootstocks grafted with Hass avocado in a controlled environment (substrate and greenhouse) were investigated. Differences in aerial and root growth and root type (rhizotrons) parameters, water and nutrient (nitrate and phosphate) use efficiency and main non-structural carbohydrates (glucose, fructose, sucrose, mannoheptulose, perseitol and starch) were observed between both evaluated rootstocks in the vegetative and flowering periods. Principal compound analysis (PCA) revealed differences between rootstocks and phenological period. Clonal propagated rootstocks were positively correlated with root growth while seed propagated rootstocks were positively correlated with aerial growth and high carbohydrate contents in the roots. Meanwhile water and nutrient use efficiency was only associated with the time but not to rootstock type. With the same water and nutrient consumption, Mexicola rootstocks achieved higher biomass production and carbohydrate accumulation in the roots which could be beneficial for flowering and fruit bearing. This results provide evidence on the importance of considering the energetic and environmental efficiency to inform the selection process of modern rootstocks; decision-making that currently ignores such important piece of information.