Fruit yield, growth and leaf-nutrient status of mangoes grafted on two rootstocks in a marginal growing area (South-East Spain)

Abstract

Introduction . Mango (Mangifera indica L.) production is rising in various subtropical zones throughout the world. The main polyembryonic rootstocks used by growers in South-East Spain are Gomera 1 and Gomera 3 (from the Canary Islands) and the most commonly used cultivars are Osteen and Keitt (from Florida, US). In this marginal environment for mango growing, it is important to determine the different rootstock qualities in order to optimise fruit production. The objective of our study was to evaluate the performance of mango cv. Osteen and Keitt on the two aforementioned rootstocks, as measured by fruit yield, scion growth and mineral nutrition. Materials and methods . A 3-year study was conducted in a mature mango orchard (14 years old) of a total of 24 trees, where eight were grafted onto cv. Osteen, another eight onto Keitt (four trees with each of the G1-Ost, G3-Ost, G1-Kt and G3-Kt combinations) and eight were ungrafted rootstocks. Fruit yield and pomological characteristics were evaluated by measuring fruit length, width and weight. Height and canopy diameter, as well as the trunk circumference of the tree, were recorded. Throughout the study period, chemical foliar measurements were taken from all trees. Results . Fruit yield in G1-Ost and G3-Kt trees proved significantly higher than that in the others. The fruit weight and length with the G3-Kt combination were greater than those with G1-Kt. Both cultivars grafted on Gomera 3 rootstock had the highest height and canopy volume. The tree-size data confirmed the vigorous feature of the Gomera 3. The N and P foliar concentration was significantly higher for Gomera 3 than for Gomera 1 in both cultivars. The K concentration was higher in G3-Kt leaves than in G1-Kt ones, but higher in G1-Ost than in G3-Ost. The leaf Mn and Cu concentrations with G3-Kt significantly exceeded those of G1-Kt. Conclusion . The height, trunk cross-sectional area, and canopy volume and diameter proved to be the greatest with Gomera 3, reflecting the vigour of this rootstock. The combinations G1-Ost and G3-Kt registered the highest fruit yield, offering promising possibilities for boosting subtropical productivity in mango.