عنوان مقاله [English]
Background and objectives: Fulvic acid has a relatively low molecular weight and contains a large number of oxygen and carbon-rich functional groups. Many of the beneficial effects of fulvic acid spray include stimulating plant metabolism, increasing the activity of transaminase and invertase enzymes, increasing bioavailability and nutrient uptake, as well as increasing crop growth and yield. Fulvic acid spraying solution helps to transfer minerals to metabolic sites within plant cells. Fulvic acid at certain stages of plant growth can be used as a major method to maximize plant production capacity. Due to the fact that calcium transfer is difficult, although the soil is rich in this element, so its foliar application is recommended. In addition, calcium deficiency leads to a decrease in root growth and leaf loss, but also leads to the production of poor quality fruits. Therefore, this study was carried out with the aim of investigating the use of fulvic acid and calcium as a spraying solution on growth and yield of Quince ‘Haj Agha Kishi’.
Materials and methods: In order to investigate the effects of fulvic acid concentration and chelated calcium on quality and quantity of fruit indices of Quince ‘Haj Agha Kishi’ conducted during 2017-2018 in kosar city, Ardabil province. The experiment was performed as a factorial in based on the randomized complete block design with four levels of fulvic acid application with concentrations of 0, 1, 2 and 3 per thousand and three levels of application of chelated calcium with concentrations of 0, 1.5 and 3 per thousand in three replications. The treatments were applied to six-year-old seedlings. The treatments were applied on the trees as a spray solution and applied three times: after fruit set, one and two months after fruit set. In this study, leaf chlorophyll content index was measured by Arnon method. The leaf area of the plant was measured with a level gauge, model AM300, In this study 10 leaves were randomly selected from each tree branch, the average leaf area was multiplied by the number of main and secondary branches, and the leaf area of each treatment was recorded as average. In order to determine the length, diameter and average weight of fruit, ten fruits were randomly harvested from treated trees, then the diameter and length of the fruits were measured with a caliper with an accuracy of 0.01 mm. Also, the weight of the fruits was determined with a scale of model GF800, made in Japan with an accuracy of 0.01 grams. Yield was calculated by measuring the total weight of the crop in each tree. Statistical analysis of data was performed using SAS 9.2 statistical software. Means were compared based on LSD lest at 1 or 5% and charts were drawn using EXCEL 2013 software.
Results: The results of data analysis of variance showed that the effects of chelated calcium and fulvic acid on leaf area, length, diameter, wet weight and fruit yield were significant (P<0.01). Based on the results, fulvic acid had a significant (P<0.05) effect on chlorophyll b and total chlorophyll content of leaf. The interaction of calcium ×fulvic acid treatments had a significant (P<0.01) effect on leaf area and fruit length. The highest total chlorophyll content of 1.20 mg.g-1 was obtained by using 3 per thousand concentration of fulvic acid and the lowest rate was 0.79 mg.g-1 in the control. The highest (5481.69 mm2) leaf area was obtained with the simultaneous use of 3 per thousand concentration of chelated calcium and 3 per thousand concentration of fulvic acid, which was significantly different from other levels. The lowest leaf area was also observed in control. Comparison of the means showed that the treatments of 3 per thousand concentration chelated calcium and 3 per thousand concentration of fulvic acid had the highest fruit yield with 167.63 and 135.30 kg, respectively. The lowest yield was recorded for control trees.
Conclusion: Increasing yield and quality is the most important goal in agricultural production. Due to the fact that biostimulants do not have adverse effects on soil and water. In order to maintain sustainable production should be used in the production program. Folic acid, as a biostimulant, improves plant metabolism and facilitates the absorption of elements. According to the findings of this study, application of fulvic acid and chelated calcium at 3 per thousand concentrations is recommended for Quince ‘Haj Agha Kishi’ to improve leaf efficiency and fruit yield.