Journal of Crops Improvement

Abstract Objective: The aim of this study was to examine the effect of selenium foliar spraying at four concentrations (0, 2, 4, and 6 mg/L) on the qualitative and biochemical characteristics of Malase-Saveh pomegranate fruit. Selenium is an essential micronutrient known for its role in plant growth, stress resistance, and fruit quality enhancement. This research sought to determine the optimal selenium concentration for improving fruit quality and antioxidant properties and to assess its role in enhancing fruit resistance to environmental stresses.
Method: The experiment was conducted in a randomized complete block design (RCBD) with three replications in a garden located in Saveh. Selenium treatments were applied at three stages: fruit formation on June 4^th, July 4^th  and Augest 4^th.  This ensured gradual nutrient uptake and allowed for comprehensive evaluation of selenium impact over different growth stages. At the commercial ripening stage, fruit and leaf samples were collected from treated and control trees. Measured qualitative traits included fruit length, diameter, shape, volume, 100-aril weight, aril length and diameter, fruit number, sunburn percentage, cracking percentage, marketability, and throatworm infestation. Biochemical traits included macro- and micronutrient levels, selenium content in leaves and fruit, soluble solid content (SSC), titratable acidity, vitamin C, phenols, anthocyanins, and antioxidant capacity. These traits provided a comprehensive understanding of selenium impact on fruit quality and plant health.
Results: Foliar application of selenium, particularly at 6 mg L⁻¹, significantly increased fruit length, diameter, volume, weight, and 100-aril weight. The number of fruits per tree was also higher compared to the control. Quality indices such as total soluble solids, titratable acidity, vitamin C, total phenolics, and antioxidant capacity improved significantly in the 4 and 6 mg L⁻¹ treatments. The highest fruit weight was obtained at 6 mg L⁻¹. Moreover, the incidence of sunburn, fruit cracking, and infestation by the pomegranate fruit borer decreased, although no significant effect was observed on fruit shape. Nutritional analysis showed that selenium application increased selenium concentration in fruit and leaves, along with higher nitrogen, phosphorus, and potassium levels. The highest iron and zinc contents were observed at 6 mg L⁻¹, whereas an antagonistic relationship was found between selenium and manganese.
Conclusions: Overall, pre-harvest foliar spraying of selenium, especially at 6 mg L⁻¹, significantly improved both quantitative and qualitative traits of pomegranate. This treatment enhanced mineral composition, vitamin C, and phenolic compounds, while reducing physiological disorders and improving marketability. Therefore, foliar application of selenium at 6 mg L⁻¹ is recommended as an effective strategy to increase yield, improve fruit quality, and reduce postharvest losses in pomegranate.

Abstract Low temperature stress is one of the most important abiotic environmental stresses that affects the growth and yield of ornamental plants. In order to investigate of some physiological and biochemical indices of four varieties of ornamental Citrus used in urban landscapes under low temperature stress conditions, a factorial experiment in a completely randomized design with three replications was conducted in the Citrus and Subtropical Fruits Research Center of Ramsar in 2015. Treatments were included the temperature with four levels (3, 0, -3 and -6˚C) and four varieties of ornamental Citrus including (Kumquat, Fingered citron, Calamondin and Limequat). Results showed that amounts of electrolyte leakage, water soaking, prolin content, antioxidant capacity, lipid peroxidation and superoxide dismutase activity were increased significantly by reducing of temperature, while chlorophyll and total chlorophyll contents were decreased. Accordingly, the lowest leaf water soaking (20.92%) and electrolyte leakage (30.81%) amount, which are destructive indices, were showed in Kamquate. Total chlorophyll amount (2.21 mg/gFW), antioxidant capacity (60.61%) and superoxide dismutase activity (26.53 IU/gFW), that are tolerability indices, were more relevant at Kamquate. In general, Kumquat could tolerate the freezing stress up to -3°C by increasing of some indices such as proline, soluble sugars, antioxidant capacity and superoxide dismutase activity.

Abstract In order to study the effect of grafting on growth and fruit quality of melon under deficitirrigation the experiment was conducted as a split plot in a randomized complete block design with three replications during 2014 on the experimental farm of Imam Khomeini Higher Education center of Jihad-e-Keshawarzi in Karaj. Treatments consisted arrangement of four grafting (melon grafted on Shintozwa and Ferro-RZ, self grafted and ungrafted melon) and three irrigation levels 60, 80 and 100 percent, based on total available water depletion. The mean comparision showed that maximum (25.54 mg/g FW) and minimum (16.98 mg/FW) sucrose content of fruits was obtained in non-grafted plants under irrifation 80% and Souski Zard grafted on Souski Zard in irrigation 60% respectively. Also, the maximum (13.2%) and minimum (8.48%) of soluble solids was related to fruit of non-grafted plants under 80% irrigation level and non-grafted plants in irrigation 60%, respectively. The highest (7.58) and the lowest (5.29) learn points by the jury (panel test) related to fruit quality were irrigation 80 and 60 percent respectively. Also, there was no signifincant difference between deficit irrigation 80% and irrigation 100% in terms of total phenol content of fruit. The results showed that the fruit harvested from Soski Zand plant grafted on Shintozwa had better quality compared to control plants under deficit irrifation.

Abstract Rashe grape cultivar grows in Kurdistan province in rain fed conditions. Microclimate conditions have a great effect on grape berry quality. Information about changes in grape berry composition in the relation to climate changes is limited. In order to measure the effects of slope and altitude on some grape berry chemical composition, a study was conducted on grape cv. ‘Rasheh’ in University of Kurdistan during 2012 and 2013. A randomized complete block design with four treatments (northern and southern slope, low and high altitude) and three replications was used. In this study, amount of carotenoids, anthocyanin, antioxidant capacity, total soluble carbohydrates, tannin and total phenol in grape berry were analyzed. Results showed that southern slope at high altitude increased amount of anthocyanin, antioxidant capacity, phenol and total soluble carbohydrates. Maximum values in the concentration of carotenoid and tannin in grape berry obtained in the northern slope and lower altitude. Berries from Northern slope and lower altitude were found to have a significantly lower anthocyanin and total soluble carbohydrates compared to other treatments. Based on these results, it can be concluded that the planting in the southern slope and higher altitude will help to grape growers for improve the qualitative characteristics of the grape berries.

Abstract Harvesting time of kiwifruit can influence quality characteristics. The current research was carried out according to a completely randomized design with three replications at Faculty of Agricultural Sciences, University of Guilan in 2009. Weight loss, flesh firmness, total soluble solid (TSS), titritable acidity (TA), ascorbic acid, total phenol content and antioxidant capacity of harvested fruit at different times was measured after four months storage at 0.5?C. The results showed that fruit weight loss was significantly increased at the end of storage time when fruits harvested with higher ?brix (more than 6.5). Furthermore, flesh firmness of these fruits was significantly reduced during storage. Delay in harvest was resulted to increase of TSS and TSS/TA. Data showed that total phenols and ascorbic acid increased significantly with delay in harvesting time up to 8.5 and nine °brix, respectively after four months storage at 0.5?C and thereafter declined, however antioxidant capacity was higher when fruits harvested with 6.5 and nine ?brix as compared with other harvesting times. Overall, although delay in harvest might increase antioxidant compounds in kiwifruit but reduced storage quality of fruits.