Rice, an inevitable staple food crop, is affected by various fungal diseases, including sheath rot caused by Sarocladium oryzae. Sheath rot disease is considered as an important disease since it causes quantitative and qualitative yield loss. This devastating disease causes yield loss ranging from 10 to 85 per cent. Most of the chemicals used to manage sheath rot disease causes remnant of the fungicides in rice seeds. As an environmentally safer method, biocontrol using spermosphere and phylloplane bacterial antagonists were tested against Sarocladium oryzae under in vitro. Among the isolated antagonistic bacteria, Bacillus megaterium (SB 4-spermosphere bacteria) and Bacillus aryabhattai (PB 4-phylloplane bacteria) were found to be effective in inhibiting the growth of S. oryzae in vitro. Bacillus subtilis (TNAU liquid formulation) is recommended as seed treatment, seedling dipping, soil application and foliar spraying to manage sheath rot disease of rice.

Rice, sheath rot, Sarocladium oryzae, spermosphere, phylloplane

The use of biocontrol agents which are more cost-effective and environmentally safer than chemical control method is studied against sheath rot pathogen. The phylloplane and spermosphere bacteria viz., Bacillus aryabhattai (PB 4) and Bacillus megaterium (SB 4), respectively were identified as effective bacterial antagonists in inhibiting the mycelial growth of rice sheath rot pathogen Sarocladium oryzae.

Balapreethi M., Sheela J., Ebenezar E.G., Arumugam Pillai M., Merina Prem Kumari S., Rajinimala N., Paramasivan M., Sabarinathan K.G. and Theradimani M. (2023). In vitro Evaluation of Phylloplane and Spermosphere Bacterial Antagonists from Rice Land Races against Sarocladium oryzae causing Sheath Rot Disease of Rice. Biological Forum – An International Journal, 15(8): 320-325.