Effect of Tillage Systems and Fertilizer on Quality and Quantity of Marigold (Calendula officinalis L.)

IntroductionThe marigold is a medicinal plant from Asteraceae family and widely used as a medicinal plant. The marigold extract is widely used in the traditional medicine and herbal therapy. According to previous studies on the medicinal plant in the natural and agricultural ecosystem, using the sustainable agricultural systems provides the best conditions for plant qualitative and quantitative production. So, the global approach in production of products especially medicinal plants is toward using the ecologic management methods in the format of sustainable agricultural systems. The objectives of this experiment were to study on the effect of using the nitrogen chemical fertilizers and the variety of composts in the format of different tillage systems on the leaf area, dry weight, flower yield and the extract yield of marigold plant.
Material and methodsA field experiment was conducted in order to assessing the effect of conventional farming, ecological management and semi ecological management systems on the dry weight and the height of plant, yield of flower, the percentage of extract and the essence of marigold, in two years of 2013 and 2014 in Fars province, Shiraz in the format of randomized complete block design with 4 replications and 12 treatments. All the data were submitted to an analysis of variance (ANOVA) and Least Significant Different test (LSD) was used to verify the significant differences among treatment means at the 5% probability level.
Results and discussionThe results of analysis of variance showed that the effect of different farming systems treatment on vegetative and reproductive growth of marigold were significant (p≤0.01) (Table 3). For example, the highest dry weight and leaf area of marigold were obtained from the conventional tillage system treatment and 165 kg ha-1 urea fertilizer. Furthermore, the highest flower dry weight, the number of flower and flowers harvest index and extract yield of marigold were achieved by reduce tillage system and 80 kg ha-1 urea fertilizer and 10 ton ha-1 waste compost (Table4). It seems that the application of chemical nitrogen fertilizer could increase marigold vegetative growth due to increase of absorption and transfer of photo assimilate and transmission of growth-stimulating hormones to lateral and end meristems. Meanwhile, improving vegetative growth of marigold and increasing photo assimilate content can be achieve more reproductive growth. So, the management of nitrogen consumption should be in a way that the maximum economical performance will be obtained. The important point in this regard is creating appropriate balance between vegetative and reproductive growth of marigold, because from the beginning of flowering, vegetative and reproductive stages are done in parallel with each other (Daneshian et al., 2013). As a whole, in case of approving this study results by the future farm studies, it maybe recommendable that application of chemical fertilizer and compost at the same time in the format of reduce tillage system leads to increase of qualitative and quantitative performance of marigold plant.
Acknowledgements At the end, I appreciate all the friends that help me for conducting this research.