Effects of Salinity on the Incidence and Severity of Sheath Blight Disease Caused by Rhizoctonia solani (Kuhn) on Some Varieties of Rice (Oryza sativa L.)

As Rice (O. sativa) becomes one of the world's most important cereal crops, its cultivation in arid and semi-arid countries relies heavily on irrigation, and soil salinity remains an environmental or abiotic danger in those regions. Aside from abiotic threats, R. solani-caused sheath blight is one of the most significant fungal diseases restricting global rice output. Because there is a strong link between environmental conditions and plant diseases, determining the effect of salinity on sheath blight disease will be critical. The mycelial block approach was employed to inoculate three rice varieties (Faro44, Faro52, and Jamila) subjected to varying levels of saline treatment. The incidence of sheath blight disease was determined and expressed as a percentage, and plant image analysis (Pliman) was used to measure and determine the severity of sheath blight disease on the affected plant parts. The results revealed that the disease incidence in Faro44 and Faro52 was greater at 8 dSm-1, while Jamila had the highest disease incidence at 6 dSm-1. The disease severity increases with rising salinity level in all varieties, and becomes quite severe when the salinity level exceeds 4 dSm-1. The study concluded that, salt stress is a severe hazard to rice cultivation, and the effect of sheath blight disease can worsen as soil salinity increases.