Pomology
S.M Gholami; M. Hadadinejad; H. Moradi; H. Sadeghi
Abstract
Introduction
Bud dormancy is one of the important issues in planting and cultivation of fruit trees that needs to be addressed in many trees such as orange (Citrus sinensis). Bud dormancy involves cessation of horizontal and vertical growth, lack of budbreak, and reduction in plant activity during cold ...
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Introduction
Bud dormancy is one of the important issues in planting and cultivation of fruit trees that needs to be addressed in many trees such as orange (Citrus sinensis). Bud dormancy involves cessation of horizontal and vertical growth, lack of budbreak, and reduction in plant activity during cold weather. One of the commercial orange cultivars is Tarocco blood orange which compared to older blood cultivars, is larger in size and with lower alternate bearing has higher marketability. The nursery trees of this cultivar are grafted on sour orange, citrange, and vigorous rootstock of citrumelo (a hybrid between trifoliate orange and grapefruit) (Talon et al., 2020). One of the major problems of nurserymen in spring grafting of Tarocco cultivar on vigorous citrumelo rootstock is the failure of about 50 percent of buds to break compared to other cultivars on the same rootstock and other similar rootstocks. This unwanted dormancy leads to a one-year delay in the nursery tree production process and unnecessary occupation of nursery space. Given the commercial importance of blood orange and the adverse effects of bud dormancy on yield and fruit lifetime, solutions are used to control and overcome this problem. One of the effective solutions is the application of cytokinins which can stimulate the growth of graft buds (Yadav & Saini, 2018).
Materials and Methods
This research was conducted in a citrus nursery at the University of Agricultural Sciences and Natural Resources of Sari, in late May 2022. Citrumelo seedlings were grown in 5.3 liter pots containing a loamy-silt soil mix in the nursery location. Tarocco cultivar buds were prepared from a seven-year-old mother orchard and T-budding was performed in June (during rootstock bark slipping). All hormone treatments were applied after graft union and before bending the branch using a soft brush on the graft buds. The applied treatments included hormone treatment (control, 5000 mg.l-1 benzyladenine, 1000 mg.l-1 kinetin, and 50 mg.l-1 thidiazuron) and treatment time (13, 15, and 17 days after grafting). After two months, some traits related to budbreak and growth of the grafted buds were evaluated.
Results and Discussion
The results showed that thidiazuron and benzyladenine treatments had better effects compared to kinetin treatment on spring budbreak and initial growth of Tarocco grafted buds. In a way that 50 mg.l-1 thidiazuron treatment had the highest number of sprouted buds (67.91), largest leaf area (118.04 cm2), highest number of leaves (16.50), especially when applied 13 days after grafting. Also, in leaf size related traits, leaf area indices, graft growth rate as well as chlorophyll and carotenoid content of Tarocco graft leaves were significantly affected by different hormonal treatments and application times, with 50 mg.L-1 thidiazuron being more effective than other treatments. Cytokinins can promote division and expansion of leaf cells and thereby result in increased cell numbers and improvement of different leaf parameters. Also, cytokinins regulate important physiological processes like photosynthesis. Application of these materials provides cell division especially in areas like buds and growth points and also possibly more buds may form on the spring graft by using these treatments during the grafting process which can lead to increased bud break and faster plant growth (Cook & Bahar, 2017). Increasing cytokinin levels can stimulate the photosynthesis process which results in increased food production, leaf growth and ultimately increased leaf area. On the other hand, cytokinins affect plant metabolism and can regulate production and accumulation of different growth factors. This may lead to a better balance in nutrient distribution and metabolic activities which in turn aids leaf area increase (Hodchek et al., 2023). Finally, according to the obtained results, it can be recommended to nurserymen of this cultivar to use 50 mg.L-1 thidiazuron 13 days after grafting as a practical and effective strategy for increasing spring budbreak, growth and development of Tarocco buds grafted on citrumelo.
Conclusions
In general, based on the results, the application of 50 mg.l-1 of thidiazuron 13 days after grafting can be considered a practical and effective strategy to enhance bud awakening, as well as the growth and development of Tarocco spring shoots on citronmelo. This practice is recommended for producers of seedlings of this cultivar.
Ara Alinejad Elahshah; Hossein Moradi; Hossein Sadeghi
Abstract
Introduction: Strawberry (Fragaria × ananassaDuch.,Rosaceae). fruitis rich of fiber, vitamin C, potassium and antioxidants. Since the balance of nutrients at the appropriate time for commercial fruit production, yield improvement and fruit quality is essential, so foliar application at key stages could ...
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Introduction: Strawberry (Fragaria × ananassaDuch.,Rosaceae). fruitis rich of fiber, vitamin C, potassium and antioxidants. Since the balance of nutrients at the appropriate time for commercial fruit production, yield improvement and fruit quality is essential, so foliar application at key stages could have a positive effect on the quantitative and qualitative characteristics of perennial crop fruits. Among essential mineral nutrients that are involved on plant physiology, micronutrients of zinc (Zn) and boron (B) because of their association with synthetic hormones are particularly important. In a study by Lolaei et al. (2012) conducted showed that the foliar application at flowering stage increased fruit quality and yield of strawberrycultivar ʻCamarosa’. The results of Rafeii and Pakkish(2014) indicated that spraying of strawberry cultivar ʻCamarosa’ with boric acid had a significant effect on yield, fruit weight, chlorophyll and leaf area. So according to the importance of micronutrients on horticultural yield improving and environmental protection, this investigation was conducted to evaluate the effect of foliar application of zinc and boron and combination of them on quantitative and qualitative characteristics of strawberry cultivar ʻAromas’ in hydroponic system.
Material and Methods: The experiment was arranged in factorial based on a complete randomized block design with 9 treatments and 9 replications in 2015 and 2016 in greenhouse and laboratory of Genetics and Agricultural Biotechnology Institute of Tabarestan (GABIT), Sari Agricultural Sciences and Natural Resources University, Sari, Iran. Experimental treatments were included: zinc at three levels (0, 100 and 200 mg l-1) of fertilizer source zinc sulfate and boron at three levels (0, 500 and 1000 mg l-1) of fertilizer source boric acid as alone or combined. Spraying of strawberry cultivar ʻAromas’ at 3 stages in hydroponic system were applied after the chilling requirement treatment. When Fruits were stained 75-80% and have appropriate size, were harvested. Traits that were evaluated include: vitamin C, antioxidant activity, total soluble solids (TSS), titratable acidity (TA), taste index (TSS/TA), pH of fruit juice, chlorophyll a, chlorophyll b, carotenoid, fruit weight, fruit length and diameter, leaf number, petiole length and plant height. The data collected were statistically analyzed using the computer software using SAS 9.1 and MSTATC, Analysis of variance techniques were employed to test the overall significance of the data, while the least significant difference (LSD) test (P ≤ 0.05) was used to compare the treatment means.
Results and Discussion: Results indicated that foliar application of Zn and B significantly affected on the vitamin C, antioxidant activity, TSS, TA, TSS/TA, pH of fruit juice, chlorophyll a, chlorophyll b, carotenoid, fruit weight, fruit length and diameter, leaf number and plant height (1% or 5% of probably level), while the Petiole length was not significantly affected. Between the different nutrient levels of zinc sulfate application at the concentrations of 100 and 200 mg l-1, boric acid application at the concentration of 500 mg l-1, the combination of zinc sulfate at 100 and 200 mg l-1 with boric acid at 500 mg l-1 play a significant role at increasing studying characteristicsexcept the content of TA. Zinc is effective at the formation of growth hormones and chloroplasts, it is also necessary for chlorophyll biosynthesis and also plays a very important role at cell division and the protein synthesis and carbohydrates metabolism. It seems this subject caused increased plant height, leaf number, petiole length, diameter, length and weight of the fruit and chlorophyll by foliar application. Boron is an element which increases weight by effect of reproductive growth and help to material production, production and transfer of carbohydrate, and nutrient by boron is necessary for fruit set and fruit retention. The results showed that zinc sulfate is effective on TSS, TA, taste index and pH, the increase may be attributed to their effects on different enzymes which are involved in the formation of proteins, acids and sugars, also enough amounts of boron in the plant, increased carbohydrate transport to fruit and areas of active growth and its effect is evident in increasing the amount of fruit sugar. Because of increased vitamin C and antioxidant capacity of plants had been sprayed with boron and zinc can be attributed to zinc that plays an active role in auxin production in plants, and vitamin C increases the production of auxin. Similarly, Kazemi (2014) reported the highest pH of fruit juice, TSS and TA at 150 mg l-1 of Zn for strawberry cultivar ʻPajaro’ and the lowest of these parameters was recorded in control. The results of our study is in accordance with Mashayekhi and Atashi(2012) who reported a significant positive correlation between chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid content of strawberry cultivar ʻCamarosa’ leaves that had been sprayed by B and sucrose. As Khan et al. (2015) simultaneously combined application of Zn and B in the ʻKinnow’ mandarin fruit increased vitamin C, tree height and fruit weight, diameter and length significantly that was consistent with our results.
Conclusions: Since the foliar application of zinc sulfate at 100 and 200 mg l-1 with boric acid at 500 mg l-1 showed significant effect on quantitative and qualitative properties of strawberry, so to reduce the environmental effects caused by the indiscriminate use of chemical fertilizers, foliar application of micronutrients is recommended as an effective management solution in the production of strawberry cultivar ʻAromas’ under hydroponic culture.
Mahsa Hamedani; Hossein Moradi; Ali Ghanbari
Abstract
The different factors such as harvest time, product handling, temperature and storage duration can be influenced on the different properties of citrus fruits and has considerable economic consequences. Therefore a factorial experiment based on completely randomized design with 3 replications was performed ...
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The different factors such as harvest time, product handling, temperature and storage duration can be influenced on the different properties of citrus fruits and has considerable economic consequences. Therefore a factorial experiment based on completely randomized design with 3 replications was performed to evaluate the effects of harvest times (start of color change, 50% of color change and full color change of fruits), storage period (0, 25, 50 and 75 days) at 7ºC on total soluble solids, titrable acidity, ascorbic acid, total phenol content, flavonoid, antioxidant capacity, anthocyanin and activity of L-phenylalanin ammonia-lyase. The results showed that the harvest times and storage period had significant effect on the measured properties. So that the after 75 days of storage, peak phenylalanin ammonia-lyase activity and total flavonoid observed concomitantly with the accumulation of anthocyanin in ripe blood orange fruit but decreased antioxidant capacity and total phenol after 25 days of storage. Also, the highest vitamin C content and total soluble solids were measured in full ripening of fruits before storing and decreased after 75 days storage. So, according to changes in all of measured characteristics, the apropriate time of harvesting of Moro blood orange was the stage of commercial maturity of fruits.
