Effects of of nitrogen fertilizer and growth promoting rhizobacteria on yield and yield component of fennel (Foeniculum vulgar Mill.)

One of the fundamental principle in sustainable agriculture is use of bio-fertilizers in agro-ecosystems in order to eliminate or reduce the use of chemical inputs. In order to evaluate the effect of application of nitrogen fertilizer and growth promoting rhizobacteria on fennel on yield and yield component, a factorial experiment conducted on the basis of completely randomized block design with three replicates at Agricultural Research Station of Ilam in the spring of 2015. Experimental treatments were seed inoculation with biofertilizer (Azospirillum/Azotobacter) at two levels (seed inoculation and non inoculation) and nitrogen chemical fertilizer at four levels (0, 40, 80 and 120 kg/ha-1). With increasing N consumption from 0 to 120 kg/ha-1 of the recommended, significantly increased plant height, number of branches per plant, umbels per plant, number of seed per umbel, 1000-seed weight, biological yield and seed yield up to 15.4, 14.7, 13.8, 11.6, 12.9, 18.3 and 16.5 percent, respectively. Also, in comparison with non-inoculation treatment, inoculation treatment increased number of branches per plant, umbels per plant and 1000- seed weight up to 16.2, 15.5 and 11.5 percent, respectively. Mean comparisons for interaction of N fertilizer × biofertilizer indicated that the treatment of seed inoculation with consumption of 40 kg/ha-1 recommended N, produced the highest seed yield. On the other hand, this treatment in addition to produce satisfactory yield, considerably decreased nitrogen fertilizer consumption which could be a step toward healthy production and sustainable agriculture.