<i>Monosporascus cannonballus</i> density in soils cultivated with different crops in Rio Grande do Norte State, Brazil

Abstract

This paper aimed to quantify Monosporascus cannonballus ascospores population density in soils cultivated with different crops. The soil samples were collected from 10 plots cultivated with cotton, mango, beans, papaya, chili, watermelon, acerola, banana, coconut and cantaloupe melons, and from one uncultivated area, located in the State of Rio Grande do Norte, Brazil. Ascospores were extracted by means of a modified method of flotation in saccharosis and quantified under stereoscopic microscope at 60X. Ascospores of M. cannonballus were detected in all studied soil samples and the means differed significantly (p < 0.05) among the sampled areas. Ascospore average density was significantly higher in the soil cultivated with cantaloupe melons (pathogen hosts), reaching 8.09 ascospores g^-1, followed by the mean densities quantified in the mango, watermelon and acerola areas, with 2.00; 2.60 and 2.10 ascospores g^-1, respectively. These results did not differ significantly among them, but differed significantly from the means quantified in the areas cultivated with beans, chili, papaya, cotton, banana and coconut, which, in turn, did not differ significantly from the results of the uncultivated soil.