Carrageenan effect on Azotobacter chroococcum in seeds of cotton pelleted with a fungicide

Abstract

Azotobacter chroococcum is one of the microorganism with greater plant growth development in cotton crops. Nevertheless, the influence of polymers on its viability in presence of fungicides is unknown. In the present study,
the effect of carrageenan polymer on the compatibility of an A. chroococcum based inoculant with Vitavax® pelleted fungicides in cotton seeds was evaluated. The experiment consisted of six treatments completely
randomized with three replications in triplicate. The addition of fungicide and polymer were varied. Estimation of cell viability, response variable, was performed at three times of drying: 0, 24 and 48 hours. Data were expressed
as log CFU mL−1. Results evidenced that despite of nature of Vitavax®, this affect viability of A. chroococcum in absence of polymer. Moreover, it was observed a significant effect of carrageenan on cell biomass in presence of
Vitavax® up to 24 hours of drying (p <0.05). This polymer proved to be able to exert an adherent and protective effect on bacteria by mitigating the harmful action of fungicide. These results indicate that the use of polymers as carrageenan represents a promising alternative to reduce the harmful effects of fungicides as Vitavax ® on soil microflora.