Screening of endospore-forming bacteria for cotton seed treatment against bacterial blight and damping-off

Abstract

Under conventional seed treatment, reports of efficacy loss or activity on non-target microorganisms foster the search for sustainable disease management alternatives. Biological seed treatment has been meeting these requirements and exerts benefits that go beyond plant health. Looking for those alternatives, 368 Endospore-forming bacterial strains were screened for the control of bacterial blight and damping-off, caused by Xanhomonas axonopodis pv. malvacearum and Colletotrichum gossypii var. cephalosporioides, respectively. From the sampled sites, the strains with the highest bacterial blight and damping-off control were obtained from Primavera do Leste and Campo Verde (MT), respectively. Those had the potential to control both diseases were obtained from Primavera do Leste. Consistent disease control with seed treatment was found with two strains: Bacillus subtilis UFLA285 and Paenibacillus lentimorbus MEN2 with disease symptoms reduced by 45 and 56%, respectively for damping-off and 26 and 76%, respectively for bacterial blight. Therefore beneficial bacteria are a plausible alternative for a sustainable disease control.