The Effect of Organic and Chemical Fertilizers on Qualitative and Quantitative Yield of Indigo (Indigofera tinctoria L.) at Irrigation Levels under Bam Climatic Conditions

IntroductionMedicinal plants are valuable resources in a wide range that scientific identification, cultivation, development and proper utilization of them can have very important role in community health, employment and non-petrol exports. Quality of medicinal plants is more important than other crops. The impact of environmental factors is significant on quality and quantity of medicinal plants. Among the environmental effective factors, irrigation and manure can be managed. Drought is considered as one of the most important factors that limited plant production in arid and semi-arid areas, where such areas are subjected to a wide range of climate variations. Water deficit stresses, permanent or temporary, limits the growth and distribution of natural vegetation and yield of cultivated plants more than any other environmental factor. Under water limitation conditions, yield of plants depend on water available content and water use efficiency. Indigo carmine is considered as a highly toxic indigoid dye. Indigo blue dye’s main component is indigotine which is extracted from the leaves of indigo. Indigo carmine is also one of the oldest dyes and it is still one of the most used in textile industry. The aims of this study were evaluation of qualitative and quantitative criteria of indigo (Indigofera tinctoria L.) under Bam climatic conditions.
Materials and MethodsAn experiment was conducted as strip plot based on a randomized complete block design with three replications at the Bam, Iran, during growing seasons of 2012-2013. Four nutrient resources (such as NPK, cow manure vermicompost, Mycorrhiza and control) and three drought stress levels based on %FC (including 100, 80 and 60 percent) were considered as experimental factors. Plant height, canopy diameter, number of branches, dry weight of leaf, dry weight of, dry yield of shoots (above ground matter), indigocarmin content and indigocarmin yield of indigo were measured and calculated.
Results and DiscussionThe results showed that at the first and second cuttings, the highest dry weight of leaf (with 751.11 and 769.24 g m-2, respectively) and indigocarmin yield (with 4.62 and 4.66 g.m-2, respectively) were observed for vermicopmost. Increasing soil water content from 60 to 100% FC at the first and second cuttings caused to increase dry weight of leaf (with 37 and 100%, respectively). Decreasing soil water content caused to reduce the dry matter yield of indigo and these highest yields were obtained in 100% FC with 1589.3 and 1829.3 g m-2, respectively. Also, increasing soil water content from 60 to 100% FC caused that indigocarmin content and indigocarmin yield increased with 36 and 18%, respectively. Relationship between soil nutrients and metabolic processes of medicinal plants causes to change of yield quantity or secondary metabolites contents. Therefore, we determined that the best growth condition for indigo was observed for manure and irrigation based on 80% FC.
ConclusionsIt was concluded that cow manure could be a good choice for decreasing chemical fertilization application.