Inoculum potential of Fusarium verticillioides and performance of maize seeds

Abstract

This work was conducted to evaluate the effect of Fusarium verticillioides on the early stage development of maize seedling/plants, considering different inoculum potentials of this fungus in seeds, under controlled conditions. To obtain seeds with different inoculum potentials of that fungus, the osmo-priming technique as referred to in literature was used. By this technique, the non-germinated seeds of the same lot, exhibiting typical structures of F. verticillioides, were grouped into five categories according to a grading system that was established based on the visible area of the seeds covered by the fungal structures. Seeds of each category were sowed in soil substrate and plants were grown under controlled conditions, 25ºC and 16 h light/day, for 25 days. All variables used, plant population (stands), speed of seedling emergence, and height/weight of emerged plants, were negatively affected by the increase of the inoculum intensity of the fungus initially present in the seeds. The regression equation showed high values of correlation coefficient (>0.85) for all variables, except for plant height which presented correlation coefficient of 0.77. The most severe effect of the fungus in this study occurred on the root system of the emerged plants as determined by the highest inoculum intensity of the pathogen on the planted seeds.