In the current research, the effects of some organic fertilizers as fulvic and humic acids on the vegetative growth of pistachio seedlings in a semi-hydroponic culture containing Fe-EDDHA (as a synthetic fertilizer) and FeSO4 (as an inorganic fertilizer) were investigated. The alkalinity is recognized as a main problem in pistachio orchards, therefore the pH of nutrient solution was adjusted to 7.5 and 8.5 (as two alkaline pHs) versus 6.5 (as the optimum pH of hydroponics) in this study. Plants were treated for 9 months under greenhouse conditions. The results demonstrated that the organic fertilizers (especially humic acid) reduced plant growth in acidic condition (pH 6.5). It can be related to precipitation of humic acid under acidity and thereby removing some essential elements for instance Fe form plant growth medium. In contrast, humic substances increased plant growth up to 2.3 times under alkalinity. The analysis indicated that these organic-stimulants can improve plant growth under alkaline conditions by increasing Fe content to about 2 times in pistachio seedlings, especially in shoots. It was noted that this result was somewhat similar in plants grown in media containing Fe-EDDHA and FeSO4. In addition, environmental and economic importance of the application of humic and fulvic acids makes them proper candidates to substitute synthetic fertilizers for agricultural improvement under alkalinity. Manuscript profile

Pistachio hull, as the dominant component of pistachio processing wastes, is a source of phenolics with antioxidant properties. Extracting these compounds from pistachio wastes has recently attracted a lot of attention. The current study aimed to identify the optimal conditions for extracting phenolics from pistachio hulls. Firstly, some parameters such as different sample to solvent ratios (1:10, 1:20, and 1:40), extraction temperatures (25, 45, and 65°C), and duration times (1, 2, and 3 h) were evaluated under extracting solvent of water. The content of total phenolics and antioxidant activity were determined using spectrophotometric methods. The results indicated that the highest phenolics (~35 mg g-1) were extracted at 2 h extraction time, 65 °C, and the sample to solvent ratio of 1:10 (optimum condition by the solvent of water). Secondly, other organic solvents of ethanol, methanol, and acetone 50% were evaluated to identify the best solvent under optimal conditions. All of these organic solvents were more efficient than water in extracting total phenolics (with antioxidant property) from pistachio hulls. However, the highest amount of total phenolics (~47 mg g-1) was extracted by ethanol. Optimizing the extraction of phenolic compounds from pistachio hulls would be important in terms of reducing human and environmental risks caused by the waste accumulation, as well as producing naturally beneficial compounds and using them instead of synthetic antioxidants in the human diet. Manuscript profile

Application of sulfur to control the common pistachio psylla has been nowadays popular. The psylla is one of the main pistachios’ pests. Aspergillus flavus, the most important aflatoxin producer, has a strong impact in the mycoflora of pistachio orchards. The present study has been conducted to determine the effects of sulfur on A. flavus. Therefore, a toxigenic A. flavus strain was cultured on potato dextrose agar (PDA) medium, and the effects of mineral sulfur, refinery sulfur and sodium metabisulfite were closely monitored on fungal mycelial dry weight, germination of spores, germ tube and mycelium germination. The Fungal parameters measurement for sulfur vapor exposure and sulfur addition to the culture medium declared no significant effect on the growth of A. flavus mycelium in the direct addition. But sulfur in liquid medium as well as in high concentrations caused mycelial dry weight loss. Importantly, the sublimation of 0, 0.5, 1, 2, 5, 10, 25 and 50 gm-3 from the refinery sulfur, prevented completely the growth of germinated spores and mycelial. Significantly, the complete inhibition of spore germination was observed at a concentration level of 2 g m-3 and also sodium metabisulfite prevented the growth of A. flavus at a concentration of 15 g l-1 culture medium. The sulfur usage in culture medium declared no inhibition of A. flavus growth, but at high concentrations in liquid medium, it reduced mycelial dry weight. Therefore, it is found that the sulfur application in any kind to control of psylla would not probably effect significantly on the aflatoxigenic A. flavus. Manuscript profile