عنوان مقاله [English]
Water and nitrogen are the most important factors affecting the quantitative and qualitative performance of medicinal plants. Since the performance of the fertilizer level depends on the appropriate amount of irrigation water, it is important to examine the water and nutritional requirements of medicinal plants in order to achieve the desired quantitative and qualitative performance and the physical and economic water productivity indexes of these plants. Celandin (Chelidonium majus L.) plant is one of the very old medicinal plants, and all its parts, especially its sap and root, were used in the treatment of skin disorders, especially leprosy, toothache, and also as a choleretic, and in recent years most of its aerial parts, which are collected during the flowering stage, are used to treat some diseases, especially cancers of the digestive system. Also, all the parts of this plant contain orange sap rich in alkaloids Chelerythrine, Chelidonine, Sangunarin, Berberine, etc., which increases the importance of the production of this plant. There are many reports about the effect of irrigation interval and nitrogen fertilizers level in relation to various agricultural, garden and medicinal plants, but there is still no comprehensive and complete information about the effect of these factors and their optimal levels for the cultivation of Celandin medicinal plants. Therefore, it is necessary to evaluate the yield and indexes of physical and economic productivity of water in Celandin medicinal plant at different levels of irrigation and nitrogen fertilizer.
In order to investigate the effect of the irrigation interval and ammonium nitrate on the yield and indexes of physical and economic water productivity of Celandin (Chelidonium majus L.) medicinal plant, an experiment was conducted as a factorial in the form of a completely randomized design in three replications in the research greenhouse of the Faculty of Agricultural Sciences of University of Guilan in 2017. The factors include irrigation interval in three levels (4, 8 and 12 days) respectively as I1, I2 and I3 and nitrogen fertilizer based on ammonium nitrate in five levels (0, 45, 60, 75 and 95 kg per hectare) as respectively was N0, N45, N60, N75 and N95. To prepare the planting bed, the top soil of the garden, dune sand, and animal manure were mixed in the ratio (1:1:1) and filled in pots with an average diameter of 20 cm and a height of 18 cm. After preparing the soil sample, some physical properties (soil moisture coefficients of FC and PWP using a pressure plate device, soil texture using the hydrometric method and dry bulk density using the core sampler method) and chemical properties of the soil (calcium, potassium, phosphorus, nitrogen, organic carbon, pH and ECe) were determined. At the end of the experiment, when the plants flowered (about 225 days after transplanting), to calculate the weight of the roots and aerial parts, the plants were removed from the pot and their roots were separated from the aerial part. After washing the roots, each one was weighed separately with a sensitive digital scale (Sartorius model) with an accuracy of 0.001 grams. Then, with regarding the amount of water consumed in each irrigation treatment, the physical and economic water productivity indexes were determined based on the wet weight of the whole plant, which includes the root and aerial parts of the plant.
The results of variance analysis of data showed that the interaction effect of irrigation interval and amount of ammonium nitrate on yield and indexes of physical and economic water productivity was significant at the 5% probability level. Thus, the highest plant fresh weight was obtained with 92.92 g/plant in an 8-day irrigation interval with a fertilizer level of 95 kg/ha, and the lowest with 45.36 g/plant in a 12-day irrigation interval with a fertilizer level of 60 kg/ha. Also, the highest indexes of physical and economic water productivity based on benefit per drop and net benefit per drop based on the fresh weight of the total plant with 8.65 kg/m3 and 3463932999 and 17319665 rials/m3 respectively in the 8-day irrigation interval treatment with fertilizer level 95 kg/ha, and the lowest of them was obtained with 2.44 kg/m3, 9774464 and 4887232 rials/m3 respectively in the 4-day irrigation interval treatment with zero fertilizer level. In addition, 50% water consumption was saved in the 8-day irrigation interval treatment compared to the 4-day irrigation interval treatment. Therefore, I2 irrigation interval treatment with N95 ammonium nitrate fertilizer level is the most suitable option in terms of yield and physical and economic water productivity indexes for the production of the medicinal plant Celandin in greenhouse conditions.