عنوان مقاله [English]
Introduction: Nitrogen is an essential element forplants and in combination withelements such as carbon, oxygen, hydrogen and sulfur results ineven more valuable materials such as amino acids, nucleic acids, alkaloids. Hibiscus tea (Hibiscus sabdariffa ) from Malvaceaefamily is known by different names in different parts of the world. In Iran it is calledthe Maki tea, tea Meccaorred tea.As an important plant,it is decided to investigate its growth and development in Jiroft.
Materials and Methods The experiment was conducted as factorial based on randomized complete block design with three replications in farm research of Islamic Azad University of Jiroft during 2010. The first factor was nitrogen foliar application in four levels (0, 1, 2 and 3 percent) and second factor was foliar application of zinc at twolevels (0 and 1 percent). The measured quantitative characteristics were stem diameter, plant height, calycle fresh weight,calycle dry weight, plant fresh weight,plant dry weight, leaf fresh weight,leaf dry weight, mucilage percentage and mucilage yield.
Results and Discussion:The results of ANOVA showed that nitrogen foliar application on leaf dry weight, calycle fresh and dry weight was effective. Plant fresh weight, dry weight, stem diameter, plant height, mucilage percentageandmucilage yield showedsignificanteffects. Zinc foliar application significantly affected leaf fresh weight,leafdry weight, calycle fresh weight, plant fresh weight,plant dry weight, mucilage percentage andmucilage yield.The interaction effect of nitrogen and zinc on leaf dry weight, plant freshweight and plant dry weight was also significant.
The mean comparison of studied characteristics revealed that byincreasing the amount of nitrogen up to N2 level, the stem diameter, plant height, leaf dry weight, calycle dry weight, mucilage percentage and yield increased but there was no significant difference between N2 and N3 levels. Plant fresh weight and plantdry weight increased with increasing amountof nitrogen up to N3 level. Theapplication of zinc fertilizer significantly increased the plant fresh weigh, plant dry weight, mucilage percentage and yield. The interactions of nitrogen and zinc improved the calycle, leaf dry weight, plant dry weight, and the highest calycle dry weight were achieved from N2Zn1 and N3Zn1 treatments.
The results showed that any givenlevel of nitrogen fertilizer and zinc fertilizer increased growth, yieldand quantitative traits of Hibiscus tea, but the level of interaction between nitrogen and zinc fertilizer hada significant effect on growth traits of Hibiscus tea, and even reduced the growth and yield of quantitative traits. The nitrogen and the fertilizer mixture of nitrogen and zinc had a significant influence on Hibiscus tea quantitative traits. Nitrogen fertilizer with a higher level of performance and yield had the greatest effect on Hibiscus tea.The greatest impact of nitrogen fertilizer, zinc fertilizer and the fertilizer mixture of nitrogen and zinc on sepal fresh weight were215.481 gr, 209.935 gr and 216.893 gr respectively.The effect of nitrogen fertilizer, zinc fertilizer and fertilizer mixture of nitrogen and zinc on leaf fresh weight,leaf dry weight andsepals dry weight were 61.787 gr 13.378 gr and 19.482 gr respectively.
Conclusion The results of this study showed thatin order to increase crop yield and quality,nitrogen fertilizer and spraying of manure on Hibiscus tea is recommended. Because of having useful properties in the treatment of diabetes, as well as the climate and soil conditions of Jiroft area, this plant is grown as a medicinal plant at a large scale. Since Jiroft region is a suitable place for growth of Hibiscus tea and due to the importance of medicinal plants, it recommend that this experiment should be repeated to evaluateplant characteristics.