Evaluation of nitrogenous fertilizer influence on oil variations of Calendula (Calendula officinalis L.) under drought stress conditions

To evaluate the beneficial impact of nitrogen fertilizer on droughted calendula (Calendula officinalis L. var. 'Qazvin') some yield characters were investigated. In this experiment, the interactive effects of different N fertilizer and water restriction on oil variations and percentage in Iran during 2009 were studied. The experimental unit had designed by achieved treatment in factorial on the basis completely randomized block design with four replications. Certain factors were including N fertilizer (0, 30, 60 and 90 kg urea/ha) and water stress. In this study, calendula water supply was determined by indicated irrigation conditions by water evaporation from evaporation pan (40, 80 and 120 mm water evaporation). The results showed that however application of N fertilizer significantly increased the yield compounds such as: oil content, seed yield, oil percentage, head diameter, thousand seed weight and number of seeds in head in p <= 0.01 of plants. Although, the non-drought stress treatment significantly increased yield compounds which were achieved under irrigation conditions (non-drought). The findings indicated that application of N fertilizer persist less damaging of drought stress result and it enabled plant to significantly increased its photosynthesis by root development and chlorophyll production under the drought conditions.