Diagnosis and Biocontrol of Sporisorium scitamineum Associated with Whip Smut Sugarcane

Abstract

Aim: Whip smut of sugarcane is the most serious and widely spread disease of sugarcane and causes a significant reduction in cane quantity and quality. This work aimed to assess the macroscopic and microscopic characteristics and the variability between isolates of Sporisorium scitamineum causal agent of smut in sugarcane. Materials and Methods: The fungus was isolated on Potato Dextrose Agar (PDA) medium. The morphological characters were described based on the growth diameter, texture, and colony colors. The microscopic description focused on the spore’s size from medium and teliospores from whips. Results: The colony appeared with white mycelial cotton and a yeast-shaped mycelial colony. In vitro, control of S. scitamineum isolates with endophytic fungi of Macrophomina phaseolina and Trichoderma viride was studied. The results showed that the two fungi could inhibit the growth of S. scitamineum. A pathogenicity test was carried out on sugarcane cuttings by inoculating the buds with spore suspension of S. scitamineum, which showed a pathogenic effect ranging from 50–100%. Also, other sugarcane cuttings were inoculated by the pathogen and Trichoderma viride as a biocontrol agent that inhibited the pathogen growth completely in four strains. Conclusion: Trichoderma viride is the safely biocontrol agent against S. scitamineum.