Effects of irrigation interval and nitrogen on seed yield and physiological characteristics of Fenugreek (Trigonella foenum-gracum L.)

In order to study the effects of irrigation interval and nitrogen on yield and some physiological characteristics of Fenugreek (Trigonella foenum-gracum L.), an experiment was carried out as split plot in randomized complete block design with three replications at Islamic Azad University of Birjand, 2009. Treatments included irrigation intervals (4, 8 and 12 days) as main plot and nitrogen fertilizer (0, 50, 100 and 150 kg.ha-1 urea) as subplot. Results showed no significant differences for seed yield in irrigation treatments after 4 and 8 days. Increasing N also led to the increase of seed yield but no significant difference was found for seed yield between 100 and 150 kg.ha-1 urea. Decreasing in water use led to the increase of Na, proline and carbohydrate and decrease of K, Cha, carotenoids and total pigments, but it had no significant effect on Chb. Nitrogen significantly increased chlorophyll a, carotenoids, total pigments, and K. Increasing N up to 50 kg ha led to the increase of carbohydrates but then reduced the carbohydrates of leaf. According to the results obtained in this experiment, it can be stated that Fenugreek is somewhat drought tolerant and considering the importance of this medicinal plant, it can be used in conditions of water scarcity as an alternative for the species that have lower economic value under water deficit.