Resumen

DIAZ-FRANCO, A; JACQUES-HERNANDEZ, C  y  PENA DEL RIO, MA. Sorghum productivity in the field associated with arbuscular mycorrhiza and Azospirillum brasilense. Universidad y ciencia [online]. 2008, vol.24, n.3, pp.229-237. ISSN 0186-2979.

In the context of sustainable agriculture, beneficial microorganisms represent an important biotechnological component. In this study, the effect of inoculation with the arbuscular mycorrhizal fungus Glomus intraradices and the plant growth promoting rhizobacterium Azospirillum brasilense on sorghum productivity (cv. DK-52) in semiarid-dryland conditions was evaluated. In 2002, the responses of sorghum seeds inoculated with G. intraradices, A. brasilense and both were compared, and a multi isolate of A. brasilense was included in 2003. The characteristics of the plants and grains were measured. In 2002, the endophytes had no significant influence (ANOVA; p = 0.05) on the height of the plant, although the yield and volumetric weight of the grain increased as did the individual G. intraradices or A. brasilense inoculations (ANOVA; p = 0.05 and 0.01). In 2003, the multi isolate of A. brasilense had no effect on the plant and grain characteristics (ANOVA; p = 0.05). The arbuscular mycorrhizal fungus G. intraradices increased plant height, leaf and root dry biomass, panicle length, and protein content in the grain (ANOVA; p< 0.05). The grain yield was greater and similar with G. intraradices or A. brasilense (ANOVA; p = 0.05). The average for the two years indicated that a greater plant height was obtained with G. intraradices (107.5 cm) (ANOVA; p = 0.05), whereas the increase in grain yield was similar with G. intraradices and A. brasilense (ANOVA; p = 0.01) and it represented on average 20.5 % over the control. The response of the sorghum to the simultaneous combination of G. intraradices and A. brasilense was inefficient in 2002 and 2003 (ANOVA; p = 0.05). The independent inoculation of the endophytes showed it is possible to increase sorghum productivity in semiarid-dryland conditions.

Palabras llave : Beneficial microorganisms; Sorghum bicolor; yield.