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Olive trees are known as one of the most iconic crops in the world. Considering the increasing water deficit worldwide, implementing some profitable and empirical strategies can be inevitable upon exposure to drought stress. Therefore, the present study aimed at clarifying the beneficial role of exogenously foliar application of Fe2O3 modified carbon nitride nanostructures (control, FeSO4, C3N4 and Fe2O3/g-C3N4) to “Shengeh” olive cultivars grown at different watering levels (100, 75, and 50% ET) in two experimental years (2022 and 2023) and the pomological attributes, physiological and biochemical changes happening in the treated leaves and fruits were discussed. The results indicated that drought stress caused a significant decline in pomological attributes in this experiment, and treatments could remarkably make up for this damage. Overall, Fe2O3/g-C3N4 outperformed as compared FeSO4 and C3N4 alone, which were also efficacious in conferring tolerance to the water deficit stress. Conversely, severe drought stressed-olive fruits showed higher oil content percent in the fresh matter and water use efficiency (WUE) in oil by 30% and 52.5%, respectively, as an average of results of two years, and after Fe2O3/g-C3N4, these features in olive plants subjected to severe drought improved by an average of 35% over two years. Ca2+ and K+ in olive plants under severe drought stress declined by 50% and 83% in 2022 and 46% and 24% in 2023, while Na+ increased in the plants exposed to 50%ET stress by 48% and 57% in two successive experimental years respectively. The application of Fe2O3/g-C3N4 remarkably improved the contents of Ca2+ and K+ by 101.5% and 369%, respectively, as an average of two years. Conversely, this beneficial treatment led to a significant decline in Na+ levels by 30% in 2022 and 2% in 2023 under stressful conditions. Moreover, it decreased the ‘osmolytes’ content, caused a smaller decline in chlorophyll levels, and resulted in higher relative water content occurring in the treated olive leaves. The reduction of oxidative markers was a result of the increased enzymatic activity after the use of Fe2O3/g-C3N4. Therefore, this treatment is a promising strategy to achieve improved resistance in olive plants in the future.

The purpose of this study was to address the influence of melatonin foliar application on the flowering and fruit formation of olive cultivars of Sevillana and Roughani at the Dalaho Olive Research Station conditions of Kermanshah province. The experiment was conducted in a randomized complete block design in a factorial arrangement and three factors (MEL concentration, irrigation regime and olive cultivar) with 3 replicates and implemented in the crop year 2021-2022. The trees were sprayed with melatonin [0 (as a control), 50 and 100 µM] before flowering and during rapid fruit growth (two growth stages) on leaves. Irrigation treatments included 100% (control), 75 and 50% evapotranspiration. In order to investigate the state of flowering and fruit formation of olive cultivars under drought stress and melatonin foliar application, flower and fruit formation were recorded. Statistical analysis of variance and comparison of averages was done by Duncan for multiple comparisons between pairs of treatment as a post-hoc test. The results showed that flower traits and fruit formation were significant under the impact of variety, various levels of melatonin and irrigation regime at the probability level of 1%. The decrease in the amount of irrigation water affected flower characteristics and fruit formation. Melatonin foliar spraying improved the condition of flowering and fruit formation in Sevillana and Roughani cultivars.

To study the lands covered by the border rivers of Kermanshah province to provide the pattern of fruit tree cultivation from 2017 to 2019 based on field studies of the target areas and the review of meteorological information, soil science, the history of fruit tree cultivation in the study areas, the pattern of tree cultivation of fruit was determined in these areas. Climatic zoning and providing a regional cultivation model is one of the duties of those in charge of production to reduce the damage to producers due to climatic factors and to control the amount of production, which helps regulate the market. Presenting a regional cultivation model in line with production policy and preventing production surplus, which by completing the production chain can overcome the problems of the past few decades in the country's fruit industry. The purpose of this project is to study and analyze the climatic, soil, and social conditions of land covered by border rivers in different parts of Kermanshah provinces that have different climates and microclimates. Also, field studies are the history of cultivation of horticultural products, and finally, the suitable species of each region and the bases appropriate to the soil conditions of those regions are suggested.

Abstract Background Drought stress is among the most serious threats jeopardizing the economic yield of crop plants in Iran. In particular, in response to withholding irrigation, the reduction in performance and quality of a precious plant such as the olive tree is remarkable. Therefore, the selection of cultivars that are resistant or tolerant to drought has been recognized as one of the most effective long-term strategies for sustainably alleviating the adverse effects of this stress. In this view, our study evaluated the response of 8 olive cultivars including 4 elite native cultivars (Zard Aliabad, Roughani, Dezful, and Shengeh) and 4 foreign cultivars (Manzanilla, Sevillana, Konservolia, and Mission) to water shortage in the Dallaho Olive Research station of Sarpole-Zahab in Kermanshah province in 2020. Olive trees underwent 3 levels of irrigation treatment including 100% full irrigation (control), 75%, and 50% deficit irrigation. Results Based on the results, 50% deficit irrigation decreased both growth and pomological traits, but determined the highest dry matter percentage. As the severity of drought stress increased, with an accumulation of sodium and malondialdehyde, an incremental increase in osmolytes was observed, as well as an enhancement of the activity of antioxidant enzymes (peroxidase and catalase). In contrast, full irrigation led to an increase in photosynthetic pigments, calcium, and potassium. Dezful and Konservolia cultivars revealed a significantly higher growth rate, correlated in the former to higher levels of chlorophyll, compatible compounds, total phenolic content, relative water content, potassium to sodium ratio, catalase, and peroxidase activities compared with other cultivars. Konservolia showed the best yield parameters under 75% and 100% irrigation regimes, correlated to higher chlorophyll, potassium, and total phenolic content (in particular at 75% ET). Conclusions Generally, the selection of more resilient or tolerant cultivars to sustain water scarcity stress is a widely operative solution to extend rainfed orchards in semi-arid environments. Our study showed that Dezful and Konservolia had the best adaptive mechanisms to cope with the detrimental effects of drought stress.

Climate change and rising global average temperatures across the year may strongly affect olive fruits’ development process and their oil yield and quality. There is therefore an urgency to take immediate actions to characterize the wide variability of cultivars in order to identify those with a stable response to high temperatures, particularly in areas like the west of Iran, which is characterized by a warm summer continental climate. The objective of this study is to investigate the process of fruit development and oil accumulation in response to high summer temperature conditions in a set of four Iranian olive cultivars (Shengeh, Roughani, Zard Aliabad, and Dezful) in comparison with four foreign olive cultivars (Konservolia, Sevillana, Manzanilla, and Mission) in seven various harvesting times (20 July, 5 and 20 August, 5 and 20 September, 6 and 21 October). The obtained results evidence a significant positive correlation between fruit dry matter and oil content. High temperatures reduced the oil and dry matter accumulation in the second half of the summer, with severe thermal conditions adversely affecting oil synthesis. Paramount variations were observed among the cultivars regarding oil accumulation, dry matter, and pomological attributes. All of them showed the highest oil content at the last harvest. Among all analyzed varieties, Roughani showed the highest tolerance and adaptive capacity to high temperatures as it accumulated the greatest amount of dry matter as well as oil content in all of the harvesting times, demonstrating a positive correlation between these two traits. Although Shengeh showed the lowest oil content on a dry and fresh weight basis at the first harvesting time, this cultivar generally presented higher fruit development attributes than the other cultivars, highlighting that it benefits from a high temperature.

In this study, effect of salicylic acid (SA) and kaolin (KL) separately and simultaneously on yield, physiological traits and fatty acids composition of two olive cultivars (i.e. ‘Zard’ and ‘Roghani’) was investigated under three irrigation regimes. Results showed that deficit irrigation, especially 50% crop evapotranspiration (ETc), increased accumulation of MDA, proline and activity of antioxidant enzymes, but decreased chlorophyll content and yield in both the olive cultivars, as compared to full irrigation (100% ETc). Applying SA and KL alleviated the harmful effect of water deficit on plants through enhancing their chlorophyll content and antioxidant activity, and accordingly improved their yield, as compared to the controls. On the contrary, low irrigation mounted some fatty acids such as palmitoleic acid, stearic acid, arachidic acid, while reduced unsaturated/saturated fatty acids. Moreover, applying SA and KL simultaneously, as compared to the controls, increased unsaturated/saturated fatty acids and the quality of extracted olive oil. In general, the results showed that a simultaneous effect of SA and KL, in comparison to their separate application, had a better effect on yield and quality of olive under water deficit.

Introduction: Olive (Olea europaea L.) is one of the drought tolerant ever green fruit trees. Olive is an economically important species of the Mediterranean area, so understanding the mechanisms by which olive plants face drought stress under environmental conditions is essential for the improvement of olive yield and oil quality. Olive is one of the fruit trees which become important in the Iranian fruit industry at the near future. Mulch is an optimizing strategy under which crops are allowed to sustain some degree of water deficit and yield reduction. Increasing crop water-use efficiency (WUE) through water conservation in the soil is an important component of dry land farming. Mulching is among the water management practices for increasing WUE. Mulch is referred to as any material that is spread onto the surface of the soil for protection against solar radiation or evaporation. Different materials, such as wheat straw, rice straw, plastic film, grass, wood, and sand, are used as mulches. Materials and Methods: This experiment was conducted to study the effect of irrigation interval and mulch on Pomological characteristics and yield of 11-years old Sevillana olive cultivar. A factorial experiment was carried out in Dallaho Olive Research Station at Sarepole located in Kermanshah province. Field experiment based on randomized complete block design with three replications and two factors (irrigation interval and mulch) were conducted in 2015. Each experiment unit consists of 4 trees and 108 trees were used. Irrigation treatments period for experiment were 3, 6 and 10 days interval and mulch treatments for experiment were polyethylene, organic materials and non-mulch (control). Geographical characters was longitude of 45˚, 51΄ E and latitude of 34˚, 30΄ N and the height of sea level 581m. The measured tree characteristics were: Fruit Weight, Pulp Fresh Weight, Pulp Dry Weight, Dry matter, Pulp/Pit ratio, Pit Length, Pit Diameter, Fruit Yield (kg/ tree) and Fruit Yield (kg/ hectare). Reproductive traits were determined by the methods of I.O.O.C.(2002). Collected data were analyzed using SAS program. Results and Discussion: Obtained results showed that mulch and interval irrigation treatments had significant differences in Pomological traits so that mulch and 3 days interval irrigation treatments increased fruit weight, pulp fresh and dry weight, fruit moisture percent, fruit yield kg/ tree and kg/ hectare but fruit weight, pulp fresh and dry weight, fruit moisture percent and Fruit yield kg/ tree and kg/ hectare reduced by drought stress. Mulch application increased fruit weight, fruit length and diameter, pulp fresh and dry weight, fruit moisture percent and fruit yield. Mulch application improved Pomological characteristics such as fruit weight, pulp fresh and dry weight, fruit moisture percent, Fruit yield kg/ tree and kg/ hectare of olive Sevillana cultivar under drought stress and helped to save irrigation water in olive orchards. In the arid and semi arid as well as sub-tropical regions, water shortage is a normal phenomenon and seriously limits the agricultural potential. Therefore, under irrigation or rain-fed conditions, it is important for the available water to be used in the most efficient way. The proper irrigation interval can play a major role in increasing the water use efficiency and the productivity by applying the required amount of water when it is needed. On the other hand, the poor irrigation interval can lead to the development of crop water deficit and result in lower yield due to water and nutrient deficiency. Early in the season when plants are small, it is beneficial to encourage the roots to explore as much of the soil profile as possible. This maximizes nutrient uptake and stress tolerance later in the season. The effect of mulch on yield and its components have been reported in various studies. The effect of mulch on plant yield through changes in soil conditions that can change the soil temperature and soil moisture that influence on the growth and yield. The effect of mulch can be done through weed control, make favorable conditions of temperature and soil moisture, reduce leaching of nutrients and soil fertility, increase the efficiency of water use, increase availability of absorption of nutrients, increased root growth and control of diseases and pests. Conclusion: According to the results of this research, it can be concluded that mulch and interval irrigation had a significant effect on reproductive characteristics. Using mulch improved Pomological characteristics of olive including fruit weight and yield per tree and hactar, fruit length and diameter, pulp fresh and dry weight, fruit moisture percent Under drought stress and helped to save irrigation water in olive orchards.

Water is the most important environmental factor in growth and fruit yield of trees. To study the effect of deficit irrigation on reproductive characteristics and yield of seven superior olive genotypes of D1, Dd1, Gw, Ps1, Bn3, Bn6, and Ds17, the present research was accomplished in Dallaho Olive Research Station of Sarpol-e zahab, Kermanshah, Iran, in 2014 and 2015. Seven superior olive genotypes were studied in a Randomized Complete Block Design with three replications and three irrigation regimes. The irrigation treatments include: 100% full irrigation (control), 75% deficit irrigation, and 50% deficit irrigation applied during the growth season. The results indicated that the genotypes had different reactions to the deficit irrigation regimes. Dd1 had the highest fruit weight while the lowest fruit weight was observed in Ps1 and Gw. The highest fruit yield was found in Bn3, Bn6, and Dd1 while the lowest was observed in Ps1. As a result, Bn6 and Dd1 are introduced as the genotypes which are resistant to drought in the field.