Rootstock’s and scion’s impact on lemon quality in southeast Spain

In terms of growth, yield and fruit quality, three lemon varieties (‘Fino49’ F49, ‘Verna50’ V50 and ‘FinoElche’ FE) were tested on three new hybrid root stock selections (Forner-Alcaide 2324, Forner-Alcaide 418 and Forner-Alcaide 5). Yield was weighed within a nine year period and fruit quality was determined in two harvests. Tree size was similar on the Forner-Alcaide 5 and Forner-Alcaide 2324 rootstocks, but reduced by 50% on Forner-Alcaide 418. Forner-Alcaide 2324 and the Forner-Alcaide 5 rootstocks showed similar cumulative yield, while it was decreased by 66% in Forner-Alcaide 418. In all cases, ‘Verna50’ was the less efficient scion. Rootstock was found to significantly affect fruit quality variables. The Forner-Alcaide 418 rootstock induced the lowest peel thickness and peel percentage, but the highest juice content and colour index. Forner-Alcaide 5, together with Forner-Alcaide 418, showed the highest total soluble sugars. In conclusion, both the Forner-Alcaide 5 and Forner-Alcaide 2324 rootstocks generate standard tree size and high yield in the varieties tested, together with great fruit quality, being a suitable alternative for replacing C. macrophylla rootstock when used in lemon varieties. Forner-Alcaide 418 reduces tree size without decreasing yield efficiency and improves alternate-bearing of the harvest. Thus, it may have use in intensifying citrus production as it behaves as a dwarfing rootstock.