Nutritional status of stone fruit trees on dwarfing and vigorous rootstocks under warm Mediterranean conditions

Fruit tree orchards are usually based on a combination of scion and rootstock. The new management trend toward orchard intensification requires rootstocks that reduce tree vigour to control tree size. For stone fruits, newly released dwarfing rootstocks (‘Rootpac^® 20’ and ‘Krymsk^® 1’) were tested in a high density planting with the well-adapted but vigorous ‘Garnem’ rootstock. Two experimental orchards of almond and peach were selected in a warm production area in northern Tunisia. A sweet almond cultivar ‘Tuono’ grafted on ‘Garnem’ and ‘Rootpac^® 20’ were planted at 2 m within rows and 4 m between rows and also 1.5×4 m spacing, respectively. For peach, tree spacing was 2×6 m on both rootstocks. This investigation aimed to explore the nutritional status induced by vigorous and dwarfing rootstocks under warm conditions. The main macro element (N, P and K) analyses were monitored for the scion-rootstock combinations. Results showed that rootstock type influenced the nutritional status of fruit trees. Dwarfing rootstock ‘Rootpac^® 20’ affected the leaf mineral contents of almond with visual chlorosis symptoms, whereas ‘Krymsk^® 1’ performed similarly to the invigorating ‘Garnem’ for peach. This study gives additional information on the adaptability of Prunus rootstocks via leaf mineral analysis as a nutritional status tool.