Influence of nitrogen content on rice leaf sheaths on sheath blight development

Abstract

This study aimed to evaluate the effect of different nitrogen (N) rates on sheath blight (Rhizoctonia solani) development. Plants from rice cultivars BR-IRGA 409 and Labelle were grown in nutrient solution containing 0, 50 and 100 mM of N. Sheath blight progress on inoculated leaf sheaths was evaluated by measuring the relative lesion length at 48, 72, 96 and 120 hours after inoculation. Data was used to calculate the area under the relative lesion length progress curve (AURLLPC). The N concentration on leaf sheaths increased by 100 and 122% for cultivars Labelle and BR-IRGA 409, respectively, as the N rates increased from 0 to 100 mM. The AURLLPC increased by 17.6 and 23.6% for cultivars Labelle and BR-IRGA 409, respectively, as the N rates increased. The results suggest that a high concentration of N on leaf sheaths of plants from cultivars Labelle and BR-IRGA 409 favored sheath blight development.