Sheath blight development and yield loss on rice in different epidemiological conditions

Abstract

Rice sheath blight and its causal agent Rhizoctonia solani AG-1 IA are associated with intensive and high input production systems. To our knowledge, resistant varieties have not been introduced for this disease, thus good crop management is expected to be among viable disease control methods. The aims of the present study were to determine the effect of different rates of nitrogen fertilizer, planting spaces and inoculum densities on sheath blight incidence and severity, including grain yield loss. Additionally we aimed to identify those developmental stages that are more susceptible to the disease. Field experiments were conducted over two consecutive years, in 2017 and 2018 in the Guilan province of Iran. Results indicated that higher N rates, denser planting and higher initial inoculum density resulted in greater disease development. Among five different growth stages, inoculation of plants at booting and flowering stages, resulted in maximum disease severity and grain yield loss. Taken together, reasonable use of nitrogen fertilizer, optimum planting space and reduced inoculum density obtained by spraying fungicide at the booting and flowering stages of rice are suggested as the best options to control sheath blight epidemics in rice.

Quantification of yield losses with relation to sheath blight development at different growth stages in mega rice varieties of South Asia

“…Some other studies point to higher yield loss even at the flowering stage (Sharma et al., 1990; Vanitha & Thangamani, 1996). The results were consistent with reports showed that significant yield loss (18.50%–20.77%) occurs at booting or flowering stage (Khoshkdaman et al., 2021).…”

“…The results were consistent with reports showed that significant yield loss (18.50%-20.77%) occurs at booting or flowering stage (Khoshkdaman et al, 2021).…”

Proteo-Molecular Investigation of Cultivated Rice, Wild Rice, and Barley Provides Clues of Defense Responses against Rhizoctonia solani Infection

“…Pusa Basmati-1, wild rice accession O. grandiglumis, and barley cv. NDB-1445 in control and R. solani infected samples at different time intervals (24 hpi [ 1 ], 48 hpi [ 2 ], 72 hpi [ 3 ], 96 hpi [ 4 ], and 120 hpi [ 5 ]). ( a ) Fold change in enzymatic activity of total phenol content.…”

“…The fungal pathogen Rhizoctonia solani has pathogenicity over a broad range of host plants. R. solani causes sheath blight (ShB) in rice and is responsible for up to 25% of yield losses [ 1 ]. This necrotic fungal pathogen has a considerable effect on the production of an extensive range of plants imperative to humanity, including the 15 largest food crops worldwide, and causes root rot disease in wheat and barley [ 2 ].…”

“…The researchers’ intentions are to sort new rice genotypes with improved disease resistance and to improve yield potential using genomic and molecular information to shatter the rice yield plateau [ 10 ]. Few early studies attempted to look for the detail of the mode of rice infection by sheath blight pathogen, which can be further utilized for the conception of resistance mechanisms against R. solani [ 1 ]. R. solani isolates produce hydrolytic enzymes such as cellular cellulase, pectolytic, and protease enzymes which help in the invasion of the host’s primary line of defense [ 11 ].…”