requires several years to achieve positive effects. For this reason,
the utilization of commercial hybrids has been the preferred
method, though genotypes evaluated as resistant 1 year may
become susceptible in the following growing season. At present,
there are no effective chemical fungicides, as the most effective
treatment only attains an efficiency of 30% (Mack et al., 1984;
Perez and Bobadilla, 2007). Utilization of B. subtilis strain 160 to
control head smut showed the highest level of efficiency at 47.6%
in 2010 and 31.9% in 2012 compared to the control.
Statistical analysis showed that treatment with B. subtilis is an
effective tool similar to fungicides for the biological control of S.
reilianum, and a viable alternative to chemical controls. Moreover,
the biological treatment applied in this work increased crop productivity.
It has been reported that B. subtilis has a beneficial effect
on seed germination and crop development, while yields also
increased due to the production of growth-promoting substances
and nutritional improvement (Nagórska et al., 2007; Stein, 2005).
5. Conclusions
This study was successful in using B. subtilis for the biological
control of head smut in the field, as in both evaluation years the
biological treatment significantly decreased the Smut Incidence
Percentage (SIP) while increasing maize productivity.
Acknowledgments
This work was financed by the Fundación Hidalgo Produce AC,
the Fondo Mixto-Consejo Nacional de Ciencia y Tecnología, the
Government of the state of Hidalgo (FOMIX-CONACyT), and the
Programa de Mejoramiento al Profesorado (PROMEP), Mexico.
We thank Jaime Ortega Bernal for his technical assistance.