ABSTRACT

The current study investigates the effects of humic acid concentration, its application methods as well as nitrogen ratios on the morphological, yield and biochemical characteristics of strawberry cv. Paros, during 2014–2015 in Ardabil Province, Iran. The study has been conducted within the framework of a double split plot randomized complete block design with three replications and density of 10 plants per replications. Different nitrogen levels (50, 100 and 150 kg ha⁻¹) were examined in the main plots while application methods of humic acid (foliar and soil) and its different concentrations (0, 2, 4 and 6 kg ha⁻¹) were considered in the subplots and sub-sub plots, respectively. The results of the analysis of variance (ANOVA) indicated that the interaction effects of different concentrations of nitrogen, humic acid and its application methods are significant on most of the measured variables at 5% probability level. Mean comparisons showed that the highest values for the leaf area, fruit yield, chlorophyll a, carotenoids and titratable acidity are associated with the combined treatments of nitrogen and humic acid with concentrations of 100 kg ha⁻¹ and 4 kg ha⁻¹, respectively. In three-way interactions, the highest shoot and root biomass and total chlorophyll content were obtained from the application of 100 kg ha⁻¹nitrogen and 4 kg ha⁻¹ foliar humic acid, while the highest nitrogen and protein contents of leaf and root were achieved upon applying 2 kg ha⁻¹ foliar humic acid and 150 kg ha⁻¹ nitrogen. Moreover, the highest amounts of ascorbic acid and total soluble solids were found at a concentration level of 100 kg ha⁻¹ nitrogen along with applying 2 and 6 kg ha⁻¹ foliar and soil humic acids, respectively. Finally, the best results of most of the studied traits were observed at 100 kg ha⁻¹ nitrogen and 4 kg ha⁻¹ foliar humic acid application.

摘要

本研究探讨了腐植酸浓度、施用方法以及施氮量对草莓品种形态、产量和生化特性的影响。Paros，2014-2015 年在伊朗阿尔达比勒省。该研究是在双裂区随机完整区组设计的框架内进行的，该设计具有三个重复和每次重复 10 株植物的密度。在主要地块检测了不同的氮水平（50、100 和 150 kg ha ^-1），同时腐植酸的施用方法（叶面和土壤）及其不同浓度（0、2、4 和 6 kg ha ^-1) 分别在子图和子图中考虑。方差分析（ANOVA）的结果表明，不同浓度的氮、腐植酸及其应用方法的交互作用对大多数被测变量的影响在5%概率水平上是显着的。平均比较表明，叶面积、果实产量、叶绿素 a、类胡萝卜素和可滴定酸度的最高值分别与浓度分别为 100 kg ha ^-1和 4 kg ha ^-1的氮和腐植酸联合处理有关。在三向相互作用中，施用 100 kg ha ^-1氮和 4 kg ha ^{-1可获得最高的枝条和根生物量和总叶绿素含量}叶面腐植酸，而叶和根的最高氮和蛋白质含量是在施用 2 kg ha ^-1叶面腐植酸和 150 kg ha ^-1氮时实现的。^{此外，在 100 kg ha -1}氮的浓度水平以及分别施用 2 和 6 kg ha ^-1叶面和土壤腐植酸时，发现最高量的抗坏血酸和总可溶性固体。^{最后，大多数研究性状的最佳结果是在 100 kg ha -1}氮和 4 kg ha ^-1叶面施用腐植酸时观察到的。