Growth and Nutritional Content of Pre-sprouted Seedlings of Five Sugarcane Cultivars Inoculated with Azospirillum brasilense Ab-V5, Ab-V6, Ab-V7, and HM053 Strains

The use of pre-sprouted seedlings (PSS) of sugarcane offers benefits such a reduction the number of stalks during planting and improvements in seedling health. The genus Azospirillum is recognized for its benefits when associated with grasses. The objective of this study was to evaluate the effects of inoculation with A. brasilense strains Ab-V5, Ab-V6 and Ab-V7 (Triazo) or HM053 on the growth and nutritional content of five sugarcane cultivars grown in PSS system. Cultivars RB867515, RB006970, RB966928, RB056351, and RB016916 were inoculated with Triazo or strain HM053. The experiment was conducted using a completely randomized design in a factorial scheme. The percentage of sprouting and roots were evaluated at 7 days after inoculation (DAI). The remaining biometric and nutritional assessments occurred at 50 DAI. Inoculation with A. brasilense (Triazo or HM053) resulted in an increase in shoot dry matter in cultivar RB006970 and inoculation with HM053 in RB056351. The highest percentage of sprouting was in RB867515 and RB966928 inoculated with Triazo. Triazo reduced root and fine root length in RB056351 at 7 DAI. Interaction between cultivar and inoculant was observed with RB867515 showing a positive effect with Triazo, RB056351 benefited from inoculation with the strain HM053 and RB016916 did not show a positive effect with the bacterial strains. The genotypes responded differently to the strain used, demonstrating that there is a specific genotype-strain interaction. In general, the Triazo inoculant demonstrated better performance compared to HM053.