Probable Effects of Dual Inoculation of Maize (<i>Zea mays</i>) Stem with <i>Fusarium verticillioides</i> and Certain <i>Trichoderma</i> Species on Fumonisin Content of Maize Seeds

Abstract

Seeds from maize ( Z. mays ) plants whose stems received various treatment combinations of pathogen ( F. verticillioides ) and four antagonists ( i.e. Trichoderma harzianum strain 2, T. hamatum , T. pseudokoningii strains 2 and 5) in the field were subjected to fumonisin analysis. Three pairing methods were employed for the inoculation of pathogen and the antagonists into stem of the maize plant, viz., “Pathogen inoculated before Antagonist”, “Antagonist inoculated before Pathogen”, and “Antagonist and Pathogen inoculated simultaneously”. Controls include “Inoculation of pathogen alone”, “Inoculation of antagonist alone”, and “Inoculation of sterile toothpicks”. Inoculation method used was the toothpick method. Seeds were harvested five weeks after inoculation and subjected to fumonisin analysis. Resulting data were subjected to ANOVA using the GLM procedure of SAS. There was a high significance among treatments i.e. there were varying levels of fumonisin occurrence among the treatments and varying Fusarium occurrences within the blocks. Seeds from treatments involving “Inoculating T. pseudokoningii strain 5 alone” and “Inoculating T. harzianum strain 2 alone” had the highest mean fumonisin content (P > 0.01) which were not significantly higher than in control. Seeds from treatments involving “Inoculating T. pseudokoningii strain 5 and pathogen simultaneously” and “Inoculating T. harzianum strain 2 before pathogen” were significantly low in fumonisin content compared to seeds from other treatments. Seeds which received “Inoculation of T. hamatum alone” were also significantly low (P > 0.01) in fumonisin content compared to others. It could thus be said that treatments involving Trichoderma species applied in the maize stem might have an effect on the fumonisin content and hence Fusarium occurrence in the seeds depending on the occurrence pattern of the Trichoderma within the maize stem.