The annual consumption of soil potassium by pistachio trees is high. Since the clay soil absorbs potassium, the amount of potassium that can be exchanged or used by the tree in the soil solution is little, and every year this deficiency must be compensated by fertilizers. To evaluate the role of potassium in improving the nutritional elements of the leaves and nuts of two pistachio cultivars (‘Ahmad-Aghaei’ and ‘Kalleh-Qoochi’), four levels of potassium fertilizer were used (0, 200, 300 and 400 mg of potassium per liter of irrigation water) in a factorial experiment in the form of a randomized complete block design with three replications. This experiment was performed on the ON and OFF branches in 2017 and 2018. The results showed that the application of potassium increased the amounts of nutritional elements in the leaf and nut. Specifically, the amounts of nitrogen, phosphorus and potassium were higher in the leaves of OFF branches, whereas the concentrations of calcium and magnesium were higher in the leaves of the ON branches. In both cultivars, the application of potassium increased the amounts of nitrogen and phosphorus in the leaf, as well as the potassium content in the nut. The amounts of calcium and magnesium in the leaf and the amount of calcium in the nuts were higher in the Kalleh-Qoochi cultivar. This treatment can be recommended when plants are in their OFF year, so that potassium can be reserve into the tissues until the ON year. پرونده مقاله

In order to evaluation of the tolerance of four pistachio rootstocks to salinity stress an experiment was performed as factorial in framework completely randomized design with four replications. Factors included rootstocks (‘Badami-e- Riz-e-Zarand’, ‘Ghazvini’, ‘Akbari’ and UCB-1) in four levels and salinity (0, 75 and 150 mM) in three levels. Results showed that rootstocks had different responses to salinity. The highest specific leaf weight and chlorophyll fluorescence parameter (Fv/Fm) were observed in ‘Badami-e- Riz-e-Zarand’ and ‘Ghazvini’ rootstocks. Also, potassium and calcium concentration of shoot in ‘Badami-e- Riz-e-Zarand’, ‘Ghazvini’ and, ‘Akbari’ rootstocks were higher compared to UCB-1. The UCB-1 rootstock had higher leaf area, relative water content (RWC) and chlorophyll-a content than the other rootstocks. The results of cluster analysis showed that salinity changed the position of the ‘Akbari’ and UCB-1 rootstocks in cluster whereas the position of ‘Badami-e- Riz-e-Zarand’ and ‘Ghazvini’ rootstocks unchanged in cluster. پرونده مقاله

Pistachio is a dioecious and cross-pollination species and suitable male genotypes is essential for its adequate fruit production. The quality of the produced nuts is also directly affected by pollen sources. In the present study, the female pistachio trees of Akbari commercial cultivar, in their ON-year cycle, were selected and hand-pollinated with three different pollen sources (T5, T17, T18) and compared to open-pollinated trees (T0). This research was undertaken as a completely randomized block design with three replications. Artificial pollination had a positive effect on the fruit set percentage. Furthermore, fruit fresh and dry weights, fruit dimensions, nut as well as kernel characteristics were affected corresponding to each pollen source. Though all 3 pollen sources had a positive effect on measured fruit characteristics, the effect of T17 was more prominent. Owing to xenia and metaxenia effects, longer nuts were observed following pollination with T5 pollen grains. Also, utilization of T17 pollen grains led to production of weightier fruits with higher splitting rate (93.33 % as compared to control, open pollinated trees (63.78%)). The results of the present study approved the imperative role of pollen source for pistachio fruit production. The results also recommended T17 genotype as a suitable pollinizer for Akbari pistachio cultivar. پرونده مقاله