Water use efficiency and morphological traits of marigold as affected by irrigation and nitrogen rates

Abstract

In order to study the effect of water deficit stress and different nitrogen levels on plant height, flower diameter, flower yield and water use efficiency (WUE) of Calendula officinalis L., an experiment was conducted as split plot design based on randomized complete blocks with three replications, at research field of Islamic Azad University of Birjand branch in 2009. In this research water deficit stress set as main factor with three levels (irrigation after 60, 120 and 180 mm cumulative evaporation from pan class A) and nitrogen set as sub factor with four levels (0, 60,120 and 180 kg N. ha-1). The results showed that increasing irrigation interval from 60 to 120 mm cumulative evaporation reduced flower dry weight and plant height 18.2 and 39.4 percent, respectively. Also in comparison with control, irrigation after 120 and 180 mm evaporation reduced flower dry yield 16.2 and 72 percent, respectively. However, the highest WUE was related to irrigation after 120 mm evaporation (0.161 and 0.788 kg.m -3 for dry flower and biomass, respectively). Nitrogen utilization significantly increased flower yield, WUE and plant height, but there was not any significant difference between 120 and 180 kg N.ha -1 treatments. Interaction of irrigation and nitrogen on all traits was not significant. Totally, the results indicated that treatment of irrigation after 120 mm evaporation with 120 kg N.ha -1 application is suitable for marigold