Effect of biological treatments and water deficit on Macrophomina phaseolina infection in sorghum

Background/Objective. Tamaulipas is the main producer of sorghum (Sorghum bicolor) in Mexico, but its unit yields are affected by biotic and abiotic factors, where Macrophomina phaseolina stands out, whose control is partially effective. In this work, the effect of biological treatments on the development of M. phaseolina in sorghum seedlings grown in a greenhouse in Reynosa, Tamaulipas, was evaluated. Materials and Methods. Two experiments were established under a factorial arrangement in plots subdivided 2 x 2 x 5 where the large plots were the Pioneer 8282 and RB Patrón hybrids; the medium plots the levels of humidity, irrigation and water deficit; and the small plots the biological treatments: strain T808 of Trichoderma koningiopsis, strain AF36 of Aspergillus flavus; Kuali® mycotoxin chelating agent; control inoculated with M. phaseolina and absolute control. Results. The RB-Patrón hybrid showed the greatest damage to M. phaseolina and the lowest growth (plant height: 10%) and accumulation of dry biomass (between 35-40%). Water deficit increased charcoal rot infection and reduced sorghum growth. T. koningiopsis strain T808 reduced the severity of charcoal rot (value of 4.6) while the other biological treatments exhibited severity values greater than 6.0. Conclusion. The treatments with better sorghum growth and less damage by M. phaseolina (T808, P-8282) should be evaluated under field conditions to confirm the viability of their application in commercial sorghum production in northern Tamaulipas.