Leaf Area Index, Dry Matter Accumulation and Allocation Trends in Vicia faba L. Affected by Inoculation with Rhizobium and Pseudomonas

To investigate the effect of inoculation with Rhizobium legominosarum and Pseudomonas fluorescens on grain yield, leaf area index, and dry matter accumulation and allocation of Vicia faba L., an experiment was conducted as a split-plot in a randomized complete block design with four replications at Agricultural Research Station of Golestan Province, during the cropping seasons of 2015-2017. As the main-factor, Rhizobium was considered at two levels of with and without inoculation, while the sub-factor included Pseudomonas in density levels of 0, 9×103, 9×105, 9×107, and 9×109 cells or CFU mL-1 of inoculants. A logistic model by SAS, was used in order to estimate the changes in the leaf area index and the dry matter accumulation. Combined analysis of variance for the two years of study indicated that the climatic conditions influenced the bacteria effects. In the second year (less temperature and rainfall), the traits (maximum leaf area index, maximum dry weight and grain yield) indicated a significant reduction in comparison with the first year. P. fluorescens had a significant positive effect on grain yield in the two years. None of the bacteria had significant effect on maximum leaf area index. Results of the first year showed a positive effect of the inoculation of Rhizobium on maximum dry weight (8%) in comparison with the control. Co-inoculation of Rhizobium with Peseudomonas (9×105 CFU mL-1) led to the greatest dry matter distribution coefficient for stems in podding stage. In the second year, Peseudomonas (9×109 CFU mL-1) increased maximum dry weight (23%) in comparison with the control. Also, the density increase of Peseudomonas under co-inoculation with Rhizobium led to a significant reduction of the day to maximum LAI. In conclusion, co-inoculation Rhizobium with Pseudomonas can have a positive effect on the growth indices of faba bean.