Using an Infrared Gas Analyzer for Evaluation of Photosynthetic Activity in Some Iranian Pistachio Cultivars

Photosynthetic rates of six pistachio cultivars were studied including Ohadi, Kalleh-Ghochi, Akbari, Ahmad-Aghaii, Rezaii Zoudras and Haratii. Measurements were done using OFF and ON shoots at different stages of fruit growth and development included: 1- Beginning of endocarp growth; 2- pith hardening; 3- Beginning of endosperm rapid growth; 4- end of embryo development; 5- ripening and harvesting times and 6- post harvest. The experiment was carried out as split-plot in a randomized complete block basic design (RCBD) with 72 treatments and three replications, which each replication included the 10 off and on branches. Results indicated that the highest amount of photosynthetic activity obtained by Rezaii Zoudras (4.15), which was followed by Akbari (4.08), Ohadi (3.79), Ahmad-Aghaii (3.7), Kalleh-Ghochi (3.58) and Haratii (3.42), respectively. Moreover in the course of experiment, the highest (5.65) and lowest (2.27) amounts of photosynthesis were resulted from stages of beginning of endocarp growth and ripening and harvesting times, respectively. These data illuminated that gas exchange efficiency can be consider to select and plant the best cvs. under Rafsajan and similar conditions.