Powder Coating Formulations with Pseudomonas fluorescens M45 Enhance the Emergence Rate and Healthy Stand Establishment of Sesame in Disease-conducive Soil

Abstract

Sesame is a major cooking oil crop in Korea. One of the primary problems in sesamecultivation is low healthy stand establishment due to the occurrence of seedling rot anddamping-off resulting from a complex of soil-borne pathogens in the field. To address theproblem, the bioformulation of Pseudomonas fluorescens M45 was prepared in powder formusing clay and vermiculite, and was evaluated for its effect on biological control of soil-bornepathogens in sesame cultivation. In the petri dish trial, the emergence rate was overall good (>92%) regardless of seeds being pelleted and/or M45-treated. In both pot and field trialscontaining disease-conducive soils, seed-pelleting substantially reduced emergence rate, whereasseed-pelleting with M45 significantly improved the emergence rate (> 26%). The emergence rateof sesame seeds treated with the strain M45 was greater than 30% regardless of seedpelletization. We also found that M45r colonized in the roots at the density of 1.6×105 cfu/g. With aid of the bioformulation, however, root colonization of the strain was significantlyincreased to 4.0×106 cfu/g. The powder formulation with strain M45 enhanced the rate ofhealthy stand establishment in disease-conducive soil. Therefore, bioformulation with strain M45is a promising method to overcome problems associated with the successive cultivation ofsesame.