Leaf mineral nutrition and tree vigor of 'Subirana' flat peach cultivar grafted on different Prunus rootstocks in a warm Mediterranean area

Recent trends in peach orchards have focused on intensification and high density plantings using different Prunus rootstock species with different vigor traits. This investigation aims to study the physiological behavior of different Prunus rootstocks in order to identify the most suitable rootstock under warm Mediterranean conditions. Field agronomic performance and foliar nutrient content of the flat peach cultivar 'Subirana' grafted on ten different Prunus rootstocks were studied on calcareous soil typical of the Mediterranean area. Ten rootstocks: 'ADAGAF 04-03', 'AGAF 0301-04', 'Garnem', 'Krymsk (R) 1', 'Krymsk (R) 86', 'PAC 847', 'PADAC 04-01', 'PADAC 150', 'PM 105 AD', and 'Rootpac (R) 70', were considered. Vegetative growth, chlorophyll SPAD index, leaf mineral status and deviation from the optimum percentage (DOP) index were determined. Leaf chlorophyll content varied depending on the rootstock. 'PADAC 04-01' and 'ADAGAF 04-03' showed higher chlorophyll index. The lowest SPAD values were observed for the most dwarfing rootstock 'Krymsk (R) 1', which showed visual chlorosis symptoms, and lower leaf mineral contents compared to the other rootstocks. Peach trees on Prunus rootstocks showed differences in leaf macronutrient and micronutrient content. 'Rootpac (R) 70', 'ADAGAF 04-03' and 'PADAC 04-01' had better adaptation under warm Tunisian conditions but high sigma DOP index. The most invigorating 'Garnem' had the highest imbalanced nutritional status, but continues to perform well under warm conditions. Interesting results were obtained with 'Rootpac (R) 70' showing one of the best balanced nutritional values (average sigma DOP index). However, the most dwarfing rootstock 'Krymsk (R) 1' presented the worst adaptation to the studied warm Mediterranean conditions.