شهره زیودار

The date palm (Phoenix dactylifera L.) tree tolerate high temperatures, drought and salinity more than other fruit crop, that is why date palm tree is named the tree of life in the desert. Date palm (Phoenix dactiylifera) is one of the fruit tree crops that is cultivated in arid region of Middle East and North Africa having a significant role on the economy of many countries in these regions. Fruit thinning is one of the major operation for improving the quality of dates as also for other fruit trees. Quality of dates is improved by increasing fruit weight and size and regulating date palm production by reducing the magnitude of year to year production affecting the date palm. Date palm orchard operations include all operations that are repeated annually to produce date fruit. Alternate bearing is common phenomenon in date palms. The thinning is one of the main methods that often helps to solve this problem. The main purpose of thinning is to create a suitable balance and often to increase the leaf to cluster ratio. It is creating a balance between vegetative growth and flowering and reducing the possibility of aging in the alternate bearing. Fruit thinning is one of the necessary operations that affects the growth, quality, fruit yield and regulation of the alternate bearing of the tree. The thinning process is performed manually, mechanically and chemically. Therefore, choosing a thinning method that saves time and money is necessary for date palms, especially in critical situations. The purpose of this experiment was to investigate the effects of manual and chemical thinning on the qualitative characteristics of date fruit at different stages of development for the Khadrawi cultivar.

An experiment was carried out as factorial experiment based on randomized complete block design with 3 replications at Shahid Chamran University of Ahvaz in 2022 and 2023. The Experimental factors included: hand thinning (No hand thinning, removal of 33%, removal of 25% of the total number of strands) and chemical thinning (zero, 50 and 100 mg per liter of naphthalene acetic acid). Chemical and strand thinning were done in the Hubabok stage (about 4 weeks after pollination) and the Kimri stage (12 to 13 weeks after pollination), respectively. In two consecutive years, the fruits were transferred to the plant physiology laboratory of the Department of Horticultural Sciences, Faculty of Agriculture, Shahid Chamran University of Ahvaz. The qualitative traits such as total soluble solids (%), pH, total acidity (%), taste index, antioxidant activity (%), total phenol (mg.g-1 FW), total soluble tannin (mg.g-1 FW), ascorbic acid (mg.g-1 FW), poly-galacturonase enzymes (U.g-1 FW), methyl pectin esterase (U.g-1 FW), cellulase (U.g-1 FW) and invertase (U.g-1 FW) and the percentage of reducing (%), non-reducing (%) and total sugars (%) were measured.

The results of this experiment showed that in the Tamar Stage, the interaction of hand and chemical thinning improved the qualitative characteristics of the fruit and on the characteristics of soluble total tannin, polygalactronase activity, pectin-methylesterase and reducing and total sugars, and the effect of hand thinning on total and percentage phenol and Non-reducing sugar and chemical thinning had a significant effect on ascorbic acid and cellulase enzyme. The results showed that there was upward trend in amount of total soluble solids, pH, total acidity, taste index, poly-galactronase, pectin-methyl-esterase, cellulase and invertase enzymes and the reducing and total sugars from the Kimri to Tamar stage. Also, there was downward trend in amount of total phenol, total soluble tannin content, ascorbic acid, and non-reducing sugar percentage from the Kimri stage to the Tamar.

The Khadrawi date variety has short strands, which results in a significant density of fruits on the strands of a cluster, which leads to large changes between fruits in most of the biochemical properties and has a negative effect on marketability. Fruit thinning is one of the most important agronomic practices in groves, as it enhances the quality characteristics of the fruit. Although hand thinning is more expensive, time-consuming, and relatively more difficult than chemical thinning, our findings showed that the quality of date fruit from the Khadrawi cultivar improved with the removal of 25% of the total number of strands and with chemical thinning using 100 mg/liter of naphthalene acetic acid. These treatments are recommended for palm growers.

In a greenhouse experiment, the responses of three varieties of paper flowers to varying levels of sodium bicarbonate and iron chelate were studied. This investigation was structured as a randomized complete block design with four replications. The treatments included three levels of bicarbonate (0, 15, and 30 mM) and three levels of FeEDDHA iron chelate [(3 μM (deficiency), 30 μM (normal), and 60 μM (excess)] and three cultivars of paper flowers (ʻBarbara Karstʼ, ʻJamaica whiteʼ, and ʻLady Mary Baringʼ). The results showed that the fresh and dry weight of shoot and root, relative water content, transpiration rate, and stomatal conductance decreased with increasing alkaline stress. Additionally, the treatment of 30 mM sodium bicarbonate and 60 μM iron chelate increased the amount of ion leakage and water use efficiency compared to lower concentrations. The ion leakage levels in the three flower-paper cultivars rose in response to alkaline stress. The relative leaf water content in the ʻBarbara Karstʼ cultivar decreased by 27.75% with rising alkalinity up to 30 mM. However, in the ʻJamaica whiteʼ and ʻLady Mary Baringʼ cultivars, these reductions were 26.49% and 2.1%, respectively. Notably, under high concentrations of sodium bicarbonate and iron (30 mM and 60 μM), the photosynthesis rates decreased significantly by approximately 45.14%, 49.80%, and 57.32% in the ʻBarbara Karstʼ, ʻJamaica whiteʼ, and ʻLady Mary Baringʼ cultivars, respectively. Based on the results, it is evident that the ʻBarbara Karstʼ cultivar exhibited superior tolerance to sodium bicarbonate stress compared to the ʻJamaica whiteʼ and ʻLady Mary Baringʼ cultivars.

The amount of leaf nutrients is directly related to the growth of fruit trees and is known as an effective indicator in diagnosing the nutritional status of trees. Investigating the dynamics of nutrient elements is necessary to provide an effective program for fertilization of orchards and improving the efficiency of fertilizer application. The olive tree is economically very important due to its adaptability to different climates and the production of fruit and oil. Understanding the physiological aspects of olive tree nutrition requires sufficient knowledge in relation to the seasonal change of leaf nutrient content, while very few studies have investigated the seasonal variation of nutrients in olive cultivars. Based on this, in the current research, the seasonal dynamics of macronutrient and micronutrient concentration in the leaves of four olive cultivars were investigated during four seasons in Ahvaz weather conditions.

This research was conducted in the olive research orchard in Shahid Chamran University of Ahvaz, in a randomized complete block (RCB) design (repeated measures) with four replications. Leaf sampling was done during 2022, from one year old shoots on 20-year-old mature olive trees of Dezful, Koroneiki, Manzanilla and Kavi. In this study, the concentration of macronutrients (N, P and K) and micronutrients (Fe, Cu, B, Zn and Mn) were measured in olive leaves.

The interaction of season and cultivar had a significant effect on the concentration of all macronutrients and the Mn. The nutritional status of the studied cultivars was optimal in terms of all elements except N.The difference in the seasonal dynamics pattern of N was evident for olive cultivars. The highest and lowest N concentration were recorded in the spring for Kavi and Manzanilla respectively.Olive cultivars showed the same and sinusoidal pattern in the change of P content during the seasons. The seasonal dynamics of K concentration, like P, had a similar pattern among cultivars, with the highest K concentration was recorded in spring and summer and the lowest in winter and autumn.The highest amount of Fe was recorded in spring (162.28 mg kg-1), but compared to the amount of Fe in leaves in winter (143.06 mg kg-1), there was a significant increase. The seasonal dynamics of Fe showed a sinusoidal pattern, so that the lowest Fe concentration recorded in winter and the highest in spring and autumn. Cu concentration significantly decreased from winter to spring and summer, and the highest concentration of Cu was recorded in winter (68.06 mg kg-1). The seasonal pattern of Cu concentration showed that it was the lowest in spring and the highest in winter and autumn. The highest B concentration was in autumn (77.36 mg kg-1). The seasonal pattern of B concentration showed an increasing trend over time. The amount of Zn decreased significantly from winter to spring and summer, and reached its highest concentration in the autumn, so that it increased by 33.80% compared to the summer. The seasonal pattern of Zn showed a decrease and then an increase during the year from winter to autumn. T. The highest and lowest concentrations of Mn was recorded in spring for Koroneiki and Kavi (72.68 and 38.10 mg kg-1) respectively.

The results of this research showed that the effects of season was more important than other effects; Because the concentration changes of all elements were affected by the season. According to the results, the concentration of P, K and micronutrients was optimal, but the amount of N, especially in the growing seasons (spring and summer), was evaluated as less than optimal level, so the application of N-containing fertilizers is suggested before the beginning of the growing season.

One of the important aspects of nutrition physiology in fruit trees is the study of seasonal changes in leaf elements, because the seasonal pattern of absorption and distribution of nutrient elements is very important in estimating the fertilizer requirement of fruit orchards. The movement of nutrients in fruit crops has been reported a lot, and the plants' need for a specific element is influenced by a specific growth stage in the plant. Research has shown that nutrient accumulation occurs as a continuous process throughout the growing season. In plants, the change process of elements is different in the seasons. By examining the dynamics of elements during different seasons and having the necessary information about these changes, it is possible to examine the relationship between the demand for nutrients during the periods of vegetative and reproductive growth.In Iran, many research has been done on the nutritional requirements of different commercial fruit cultivars, and many studies have reported the dynamics of nutrients in fruit trees during the growing season, but in the case of dates, despite the relative diversity Regarding the cultivars of this plant and Iran's presence in the international competitive markets, there was no report on measuring the dynamics of nutrient elements during the seasons. In the upcoming research, the seasonal evaluation of the concentration of some macronutrients and micronutrients in the leaves of three date varieties has been done.This study was carried out in order to evaluate the seasonal changes in nutrients in the leaves of three date varieties. This experiment was conducted in the date palm research garden in the northern part of Shahid Chamran University of Ahvaz, in a randomized complete block design with four replications, during 2022 on the leaves of ten years old date palm cultivars (Berhi, Estamaran, and Zahedi). In this experiment, the trend of seasonal changes in macro nutrients (nitrogen, phosphorus, potassium and calcium) and micro nutrients (iron, copper, boron, zinc and manganese) concentration, were investigated throughout the four seasons.After collecting the data, the data was statistically analyzed using SAS 9.1 statistical software, and Duncan's test was used to compare the average data at the level of one and five percent. The results showed that the seasons have a significant effect on the concentration of the elements except nitrogen and manganese. Also, the interaction of season and cultivar had a significant effect on the concentration of all nutrients. In terms of macronutrients, Berhi had a better condition, especially during the growing season (spring and summer). The highest difference in terms of element concentration was observed between the winter and growth seasons for date cultivars. The minimum concentration of nitrogen (0.94%) was for Zahedi in spring and winter and the maximum concentration was 2.01% for Barhi (winter). Phosphorus concentration was recorded from the lowest (0.13%) in winter and spring to the highest (0.36%) in summer for Barhi. The range of potassium changes ranged from 1.01% (Estamaran, autumn) to 1.18% (Zahedi, winter). The seasonal changes in calcium concentration was recorded between 0.76 and 0.92%. Also, the range of changes in iron concentration during the year was from 65 to 130 mg/kg and during the growing season to mid-summer from 87 to 117 mg/kg. Bades on the results, leaf iron concentration was estimated to be less than optimal in all seasons. Also the concentration of nitrogen, potassium and copper in leaves decreased during the growth season, especially in summer, and can be due to the consumption of these elements for reproductive growth. The concentration of minerals in plants depends on the interaction of several factors including soil, plant species, climate, growth stages, plant production and management and the interaction of elements during absorption. The successful growth of plants and trees requires suitable soil and the presence of sufficient amounts of usable elements and the relationship between them, among which nitrogen, phosphorus and potassium elements are among the main essential elements required by the plant.The results showed that there is a significant seasonal variation in macronutrients and micronutrients in three date varieties. Also, different seasonal changes patterns were observed among cultivars regarding elements. In such a way, potassium and calcium are more stable than nitrogen and phosphorus during different seasons of the year. Macronutrients (phosphorus and calcium) and micronutrients (zinc, boron and manganese) were at the optimal level. But, the amount of nitrogen, potassium, iron and copper was evaluated as less than the optimal level, which suggests the use of fertilizers containing the mentioned elements at the end of winter..

Olive trees are among the most important fruit crops globally, with particular importance in both the Iranian and international fruit production industries. During the past decades, in Khuzestan province, like in several other regions, many olive orchards were established without considering the selection of suitable cultivars. As a result, these trees face various issues related to flower production, such as insufficient flowering, poor fruit set, and a decrease in oil content. Several methods can address these challenges, with girdling be one of the most effective. Girdling, a method of bark pruning, encourages early flowering and fruiting, thereby enhancing the tree's productivity. This research aimed to investigate the effects of girdling at different times on the flowering and biochemical characteristics of three olive cultivars (Conservalia, Roghani, and Mission), which are known for poor flower production.

This experiment was conducted at the olive research orchard of the Faculty of Agriculture at Shahid Chamran University of Ahvaz, using 20-year-old olive trees during the 2022-2023 growing season.  The study investigated the effects of girdling on the quantitative and qualitative aspects of flower production as well as certain biochemical indicators. The experiment followed a split-plot design within a randomized complete block design, with four replications. The main plots included three olive cultivars (Conservalia, Roghani, and Mission), and the sub-plots consisted of four girdling treatments: control (no girdling), and girdling conducted in January, February and March.

The results revealed that girdling at all times increased the number of flowers per inflorescence compared to the control treatment. The highest number of flower in the inflorescence was observed with January girdling (18.17), which was more than double the control (9.1). The Roghani cultivar produced the highest average flower count per inflorescence (14.87). January girdling also resulted in the highest percentage of complete flowers (49.92%), with the Mission cultivar showing the highest percentage of complete flowers (45.31%). The relative water content in leaves was highest with January girdling (84.49%), significantly surpassing the control, February and March treatments. The Mission cultivar had the highest relative water content at 72.33%. Girdling significantly increased the fresh leaf weight in ringed branches, with the effect was diminishing from January to March. Roghani exhibited the highest leaf dry weight (14.94 g), which was not significantly different from Mission's leaf dry weight (13.69 g), but was significantly higher than Conservalia's dry weight. The highest leaf dry weight was recorded with January girdling (17 g), which was significantly higher than the other treatments. In terms of total soluble carbohydrates, the highest amount was observed in the Roghani cultivar in June (22.23 mg/g). Girdling increased total soluble carbohydrate content, although this effect diminished from January to March. Overall, girdling improved flowering traits, with increased numbers of flowers, fresh and dry flower weight, and a better flowering initiation. Roghani and Mission cultivars exhibited superior results in terms of flowering characteristics, carbohydrates, leaf water content, and leaf dry weight.

The immediate effect of girdling is the restriction of sap flow from the leaves to the roots, leading to the accumulation of sugars and plant hormones in the upper part of the tree. These accumulated materials are then transferred to the growing buds and inflorescences, promoting their development. . In this experiment, girdling was shown to improve flowering characteristics, with January being the most effective time for girdling across the olive cultivars tested. Therefore, January girdling is recommended for improving flowering and productivity in olive trees in the Ahvaz region.

 Citrus fruits are susceptible to a number of fungal diseases that cause significant losses in the citrus industry in the postharvest stage. Worldwide, diseases have been primarily controlled for many years by the application of conventional fungicides. However, human health risks and environmental contamination associated with chemical residues and the proliferation of resistant strains of the pathogens are major problems associated with the continuous and widespread use of conventional postharvest fungicides. Heat and UV radiation treatments are the most common physical means used to control postharvest diseases of fresh fruits. The aim of this study was to investigate the effects of UV-C radiation and Hot Air Flow (HAF) treatment on decay control and some biochemical properties in Thomson navel oranges at cold storage.

In this experiment, the effects of heat treatments (37 °C for 24 hours), UV radiation (7.98 kJ / m2) and combination treatment (HAF*UV) on the storage life of Thomson oranges were investigated. The statistical model of factorial experiment was in the form of a completely randomized design in which two factors of storage time and treatments were considered. After treatment, the fruits were stored at 5 ° C for 90 days during the storage period, the percentage of decay, fruit weight loss, and some biochemical properties and enzymatic activity were investigated. Statistical analysis of data was performed using SAS software and the mean data were compared using Duncan's multiple range test at a five percent probability level using MSTATC software.

The results showed that radiation and heat treatment effectively reduced fruit rot . the lowest and highest percentage of cumulative rot was observed in the combined treatment with an average of 3.8% and the control treatment with an average of 12.7%, respectively.The control treatment and the combined treatment with the average of 5.68 and 2.94, respectively, had the highest and lowest fruit weight loss. During fruit storage, TSS, TA, TSS/TA and pH increased and TA decreased The amount of ascorbic acid in fruits treated with hot air flow with an average of 35.54 mg per 100 g of fresh material was higher than the control treatment with an average of 30.67 mg per 100 g of fresh material. Antioxidant activity increased at the beginning of the period, however, the treatments did not have a significant effect on inhibiting DPPH radical activity in fruit flesh The amount of total phenol, peroxidase and polyphenol oxidase enzyme activity in fruit flesh under the influence of heat treatment, initially increased with the period, which the enzyme activity decreased with increasing storage time.

The results showed that radiation and heat treatment were effective in controlling post-harvest decay of Thomson oranges. Radiation had no significant effect on the biochemical changes of Thomson Novel orange fruit. According to the evaluated traits, heat and combination treatment succeeded in reducing the rate of rot and increasing the biochemical properties of the fruit during storage, so it can be considered as a suitable practical option.

This study was conducted to investigate the effect of foliar application of volck mineral oil (0, 1, 3 and 5%) on photosynthesis, gas exchanges and physiological traits of two olive cultivars (Manzanilla and Khediri) as split plot based on randomized complete block design with four replications during 2019-2020 in Ahvaz climatic conditions. The results showed that the application of 5% volck oil reduced photosynthesis in Khediri and Manzanilla cultivars by 40 and 52.4% compared to the control treatment in the second week after foliar application and then the photosynthesis rate increased again. In Khediri and Manzanilla cultivars, transpiration rate increased with the use of volck oil in all three concentrations compared to the control, but there was no definite trend. Stomatal conductance was higher in Khediri cultivar than Manzanilla cultivar and the highest stomatal conductance occurred 45 days after treatment. The lowest and highest leaf temperatures were recorded in control and 3% of volck oil treatment with mean temperatures of 29.34 and 32.17 ° C, respectively. In both cultivars, a decrease in radiation use efficiency was recorded in response to volck oil and high percentage of leaf drop (59.05%) was observed in Manzanilla. Therefore, in order to use high doses of volck mineral oil for olive trees, it should be done more cautiously due to the reduction of photosynthesis and increase in leaf temperature in both cultivars and the high rate of leaf drop in Manzanilla cultivar.

Olive (Olea europaea L.) is an evergreen tree and one of the most important products of the horticultural section in Iran due to high nutritional value of its oil and fruits. Adaptation of olive cultivars to the climatic conditions of different regions are not the same. The results of studies showed that special cultivars are recommended for each region. In tropical and subtropical climates with mild winter such as Ahvaz, the chilling requirement of olive trees is not completed. This condition has led to poor and insufficient flowering in some olive cultivars. Mineral oils, including volck oil are one of the most beneficial treatments to complete chilling requirement and bud break in fruit trees. The aim of this study was to investigate the response of two olive cultivars (Manzanilla and khaziri) to the application of volck mineral oil and studying their flowering and biochemical characteristics in Ahvaz condition.

In this experiment, the effect of volck mineral oil spraying [control (water spray), 1, 3, 5 %] on two olive cultivars were investigated. The experimental design was split plot arranged in complete block design with four replications. Measured traits included flowering characteristics such as the number of inflorescences in the branch, flowers in inflorescence, complete flowers, flowering days after treatments, percentage of flower fall, fresh and dry weight of flower and inflorescence. Biochemical properties such as bud carbohydrates and ABA, leaf proline and chlorophyll were measured.

The results showed that foliar application of 3 and 5 % volck oil caused flowering (31.8 and 28.7 days after treatment, respectively) in Manzanilla cultivar. Bud carbohydrate content increased significantly after tree spraying with volck oil in all of three concentrations. The highest content of bud carbohydrates (78.68 mg/g) was obtained in khaziri when treated with 3% volck oil. The use of volck oil was effective in increasing the ABA concentration in Manzanilla cultivar and its effect was as 3 and 5% volck oil (83.1 and 105.4 µg/g, respectively). The amount of proline in both cultivars increased until 60 days after applying three concentrations of volck oil. The levels of chlorophyll a, chlorophyll b and total chlorophyll increased until 30 days after treatment and then were decreased. Volck oil (3%) can be used for flowering of Manzanilla cultivar in climatic conditions of Ahvaz.

Based on the obtained results, it seems that the effect of volck oil on flowering and biochemical traits depends on the type and concentration of mineral oil and type of the cultivar. In the present study, flowering occurred when Manzanilla cultivar treated with mineral volck oil (3 and 5%) and the flowering traits were improved at 3% oil more than other treatments.

The aim of this study was to assess the crop water stress index (CWSI), derived from leaf temperature using infrared thermometer measurements, to investigate the water stress status and irrigation timing of olive trees. Fpr this purpose a regression function was determined between crop water stress index and relative water content of leaf (RWC) and soil water content (SWC). The experimental treatments involved two olive cultivars (Koroneiki and T2) and four water regimes (irrigation of 100, 85, 70 and 55% of crop water requirement). The results showed that the non-water stressed baseline is varied throughout the study period as well as during the day. The daily variations of non-water stressed baseline were mainly due to variations in the intercept of the non-water stressed baseline that can be explained by variations in zenith solar angle. After investigating the relationship between vapor pressure deficit (VPD) and the difference between crop and air temperature (), the equation of Tc-Ta = -0.45 VPD+1.06, r2 = 0.99 was determined for the non-water stressed baseline of the olive trees at 12:30 pm. The effect of irrigation regime on water stress index of Kroneiki and  olive trees was not significant in none of the measurements during the study period. However, crop water stress index was significantly correlated with relative water content (Kroneiki: r2=0.67**, : r2=0.88**) and soil water content (Kroneiki: r2=0.74**, : r2=0.78**). Therefore, the crop water stress index is a good indicator of the water stress status of the Koroneiki and T2 olive trees.

Spectrometric measurements have the potential for fast and non-destructive measurements of plant water stress. The aim of this work was to investigate the ability of several spectral water indices, including water index (WI), normalized spectral water indices 1-5 (NWI 1-5), and normalized water index based on wavelengths in 960 and 940 nm (NWI 960-940) for detection of water stress in olive trees. The experimental treatments involved two olive cultivars (Koroneiki and T2) and four water regimes (100%, 85%, 70%, and 55% of crop water requirement). Results showed that the olive trees in different water supplies 85%, 70%, and 55% of ETc were subjected to soil moisture deficit equal to 11, 15, and 20%, respectively, as compared to soil moisture of control treatment. Because of the high resistance of olive trees to water stress, water reduction at levels of 15, 30, and 45 percent did not have significant effects on spectral indices. However, spectral indices were closely and significantly linear associated with relative water content of the crop leaf (). Among all tested water spectral indices, NWI-2 showed the least consistent associations with relative water content of the leaf (ranging from 1–23% less than the ones in other tested indices). Based on the average amount of spectral indices and relative water content during the study period, NWI4, NWI5, NWI1, WI, NWI960-940, NWI3, and NWI2 showed a stronger relationship with the relative water content of olive leaves, respectively. In conclusion, spectral reflectance indices, WI, NWI 1-5, and NWI 960-940, could be useful for fast and non-destructive estimating of plant water stress.

In order to evaluate the effects of foliar application of potassium sulfate on some quantitative and qualitative characteristics of three olive (Olea europaea L.) cultivars, two split plot field experiments, arranged in complete block designs with three replications, were carried out through 2012–2013 in an orchard located in Ahvaz, Khuzestan province, Iran. Three olive cultivars (Mission, Coronaiki and Dezfuli) and three foliar applications of potassium sulfate (0, 1 and 2 g.L-1) were randomized in main plots and sub-plots respectively. The interaction effect between year and cultivar was significant for fruit fresh weight, dry weight of fruit pulp, stone weight, pulp: stone ratio, oil content (P≤0.01) and fresh weight of pulp (P≤0.05). Also, the interaction effect between year and foliar potassium application was significant for fruit fresh weight, dry and fresh weight of fruit pulp (P≤0.01) and stone weight (P≤0.05). The interaction between cultivar and foliar application of potassium sulfate for fruit fresh weight, dry and fresh weight of fruit pulp was significant at 1% probability level. In addition, interaction effect between year, cultivar and foliar application of potassium sulfate was significant for fruit fresh weight, dry and fresh weight of fruit pulp, oil content of the fruit pulp (% D.W.) at 1% probability level, and other traits at 5% probability level. Thus, it can be concluded that annual variability in the growth environment had an important effect on the parameters studied in this experiment. Dezfuli cultivar had more oil content than other cultivars that could be due to genetic diversity among cultivars for using sources in enhancement oil content and also more compatibility with the environmental conditions in this area. Foliar application of potassium sulfate increased unsaturated fatty acids and decreased saturated fatty acids in Dezfuli and Coronaiki cultivars. The highest content of oleic acid and oleic acid: linoleic acid ratio (60.54 % and 8.38) was found in Coronaiki cultivar with foliar potassium application (2 g.L-1) and the lowest amount in Dezfuli cultivar with control treatment (48.90 % and 1.67). Therefore, year conditions as well as foliar application of potassium sulfate can have a positive impact on ftuit weight, percentage of olive oil and fatty acid composition.