Harnessing bacterial bioagents to control sheath blight of rice

Sheath blight is caused by the fungal pathogen <italic>Rhizoctonia solani</italic> which causes yield losses of 20% up to 70%. While fungicide application is indeed effective against <italic>R. solani</italic> and can be safe when applied correctly, improper applications can have potentially negative effects on the environment and animals and may lead to fungicide resistance in pathogen subpopulations. The present study aimed to evaluate the efficacy of formulated bacterial bioagents in controlling sheath blight pathogen <italic>R. solani</italic> and sheath blight disease of rice to assess their performance in increasing rice yield. Out of 23 bacterial isolates, four bacterial isolates of different species viz. BDISO45JoyR (<italic>Bacillus subtilis</italic>), BDISO49JoyR (<italic>B. subtilis</italic>), BDISOB219R (<italic>Pseudomonas taiwanensis</italic>), and BDISOB221R (<italic>Pseudomonas</italic> sp.) were found to be the most effective against <italic>R. solani</italic>. These four bacterial isolates were formulated using talcum powder as a carrier material in the laboratory. Under field conditions, the formulated bacterial bioagents significantly reduced the lesion length and tiller infection of sheath blight, with BDISO45JoyR (<italic>B. subtilis</italic>) showing a maximum reduction of 55.25% and 54.80%, respectively, over the untreated control. The minimum reduction of lesion length and tiller infection was 28.30% and 32.17% was recorded in BDISOB219R (<italic>P. taiwanensis</italic>). BDISOB221R (<italic>Pseudomonas</italic> sp.) showed a maximum plant height of 116.5 cm. All the formulated bacterial bioagents showed better performance over control that increased yield. The maximum yield of 5.28 t/ha with a 58.51% increase over control was observed with BDISO45JoyR (<italic>B. subtilis</italic>) treatment compared to the untreated control. Therefore, bacterial bioagents should be considered for use in disease prevention and for the healthy growth of plants.