The Effect of Inoculation of Growth-Stimulating Bacteria on Some Leaf Growth Traits and Nutritional Elements of Hazelnut Seedlings Under Field Conditions

Growth-promoting bacteria are among the beneficial soil microorganisms, and by improving the soil quality, they increase the growth and nutritional traits of the plant. Therefore, in order to investigate the effect of growth-promoting bacteria on the leaf surface, specific leaf surface and absorption of nutritional elements of hazelnut seedlings, a factorial experiment was carried out in the form of a randomized complete block design in the field conditions. The main factor was the origin of the seedling (at two levels: Fandoglou and Makesh) and bacterial inoculation (at five levels: P. putida, B. subtilis and E. cloaca, combination of them and Control) with three replications. Twelve seedlings were planted at a distance of 3 × 3 m in holes with dimensions of 50 × 50 × 50 cm on an area of 3240 m2 in the agricultural lands at the neighborhood of Fandoglou forest in Ardabil. The results after four years showed that the inoculated seedlings of both origins were superior in terms of all investigated traits compared to the control (un-inoculated) seedlings. The highest amount of traits was assigned to the seedlings of Fandoglou origin inoculated with the combination of all three bacteria (P. putida, B. subtilis and E. cloaca). The leaf area and specific leaf area were 53.1 and 37.7% more in the inoculated seedling compared to the control, respectively. The concentration of nitrogen, potassium, phosphorous, iron and zinc in the seedling leaf increased by 59.4, 89.5, 23.7, 45.4 and 60.6% compared to the control, respectively. Finally, it can be concluded that the planting of hazelnut seedlings inoculated with growth-stimulating bacteria (combination of the three mentioned bacteria) will have more vegetative growth.