Use of beneficial bacteria Azospirillum brasilense Sp245 on grapevine rootstocks grafted with 'Sangiovese'

Azospirillum brasilense Sp245, a well-known PGPR (plant growth-promoting rhizobacteria), was examined in order to evaluate the effects on nursery propagation. In addition the aim was to test the ability of the inoculated bacterium to improve the rooting parameters of some rootstocks that do not easily root through conventional techniques. Nine rootstocks were tested in a conventional nursery, while two rootstocks were tested in organic nursery: V. berlandieri × V. riparia 420A, 161-49, 157-11, SO4; V. berlandieri × V. rupestris 140Ru, 775P, 1103P; V. riparia × V. rupestris 101-14, 3309C. The quality of the root system was improved in terms of the number of roots, root architecture and the total biomass of vines produced in the organic nursery, while in the conventional nursery the results depended on the rootstock. The results suggest that further study is needed for a better comprehension of the mode of action and to establish how PGPR could be used for the sustainable production of grapevine plants.