Figure 7From: Physiological responses to humic substances as plant growth promoterPlant growth-promoting bacteria (PGPB) colonization by most probable number method of fresh root tissues of maize seedlings. After 7 days of inoculation with a suspension of 109 cell · mL−1 of Herbaspirillum seropedicae and in the presence of 20 mg C L−1 of different humic acids (HA): HAv, vermicompost; HAfc, from filter cake a residue of sugarcane factory; HAi, inceptisol; HAo, oxisol; and HAu, ultisol.Back to article page