Effectiveness of Azospirillum brasilense Inoculants to Wheat (Triticum aestivum) in the Micro-region of Curitibanos (SC)

Abstract

Aims: This work aimed to evaluate the effectiveness of A. brasilense inoculants to the development of wheat at the southern part of Brazil.
 Study Design: The experimental design was randomized block with twelve treatments, containing two liquid inoculants with the A. brasilense strains Ab-V5 and Ab-V6, with or without nitrogen fertilization and five replicates. The plot area was 4m per 6m and thirty-two rows. The seeds inoculation was performed according to the manufacturer's recommendation, and manual sowing. The top-dressing N fertilization was Urea (Super N- 45%N) at 20 days after emergence (DAE), at 120 kg ha-1 (full dosage) or 60 kg ha-1 (half dosage).
 Place and Duration of Study: The experiment was performed in a farm in Curitibanos county in Santa Catarina state, Brazil. The experiment was carried out on July to November 2016.
 Methodology: At 45 DAE, it was performed flag leaves N content Tedesco, et al. [1]. At 115 DAE, it was performed dry shoot weight, plant height, ear sizes, grain N contents and grain yield. The results were submitted to variance analysis (ANOVA) and media compared by Scott-Knot's test at 5% of significance.
 Results: There was no statistical difference for shoot dry weight, plant height, ear size and yield. The N leaf content was greater with Ab-V5 inoculation and half N dosage (HC5 - 109% higher than the control). The N grain content was greater with the two strains (inoculant B) without, half and full N dosage (WC56 - 51%, HCB56 - 76% and CB56 - 65%, respectively).
 Conclusion: A. brasilense strains had the ability to increase wheat N accumulation with lower N fertilizing, suggesting their potential as growth inducers, emphasizing the importance of further studies to confirm and understand the mechanisms involved.