Agriculture & Food, Volume 7, 2019

Abstract: Rootstocks play an important role in the rapid development of World citrus industry. The necessity of using rootstocks for citrus fruits is to have a profitable production against some limiting factors such as climate, bad soil conditions, diseases, etc. In addition, scion behavior depends in part on the rootstock-induced effects on leaf gas exchange. In the present study, photosynthetic performance and fruit quality of ‘W.Murcott’ mandarin variety grafted on three new citrus rootstocks (Bitters, Carpenter and Furr trifoliate hybrids) developed by a rootstock breeding program in USA together with local sour orange were evaluated under Adana ecological conditions. Effects of rootstocks on photosynthetic performance were assessed by Net photosynthesis (PN), transpiration rate (E), stomatal conductance (gS), leaf water use efficiency (WUE), chlorophyll concentration (SPAD readings), chlorophyll fluorescences (Fv’/Fm’). Rootstocks significantly affected (p<0.05) the scion leaf chlorophyll concentration and chlorophyll fluorescence (Fv’/Fm’). Leaf of trees on local sour orange had higher PN than Bitters, Carpenter and Furr trifoliate hybrids. Slight increases in fruit weight (g) and diameter (mm) were observed from fruit samples on Furr trifoliate hybrid. In addition, rootstocks significantly affected total citric acid content, which ranged between 0.68% (Bitters) and 0.78% (local sour orange).