Effect of some plant growth promoting rhizobacteria and nitrogen fertilizer on morphological characteristics of german chamomile (Matricaria chamomilla L.)

In order to investigate the effects of plant growth promoting rhizobacteria and nitrogen fertilizer on morphological traits of german chamomile (Matricaria chamomilla L.), a field experiment was carried out as factorial based on randomized complete block design with three replications in Research Farm of the Faculty of Agriculture, University of Tabriz, Iran, during 2007-2008. Factors were inoculation with plant growth promoting rhizobacteria (B0: no-inoculation, B1: inoculation with Azotobacter chroocuccum, B2: inoculation with Azospirillum lipoferum and B3: inoculation with a mixture of two bacteria) and nitrogen fertilizer (N0:0, N1:50, N2:100 and N3:150 kgN.ha-1). Results showed that inoculation with bacteria significantly improved plant height, stem diameter, number of lateral branches, number of flowers per plant, dry weight of flowers, stems, leaves and total dry weight per plant. These traits were significantly similar for inoculation with Azotobacter, inoculation with Azospirillum and inoculation with a mixture of two bacteria. Effect of nitrogen fertilizer on all traits (except number of lateral branches) was positive, but there were no significant differences among 50, 100 and 150 kg.ha-1 nitrogen. The highest and the lowest number and weight of flowers per plant were recorded for inoculation + 50 kg.ha-1 nitrogen application and no-inoculation + no-fertilizer, respectively. In general, application of biofertilizers had positive and significant effects on morphological traits of german chamomile. In addition, with adding 50 kg N.ha-1 the performance of bacteria increased and the highest flower yield were produced.