Bioformulation of Antagonistic Bacterial Consortium for Controlling Blast, Sheath Blight and Bacterial Blight Diseases on Rice

Abstract

Among diseases affectmg nee production, blast. sheath and bacterial leaf bhght causes s1gm.f1cant losses. ThJ.S study was aimed to control multiple rice diseases usmg beneficial bacterial consortium as an alternative biocontrol strategies. Jn l'ilru, gTe1-rnhouses and field tesl were earned out lo study ant.agomstic effect of bacterial consortium ago.rnst l'lCC pathogens. The bacterial isolates used m single or m rruxture combination were appari>nl. to rPduce sheath blight, neck blast and bacterial leaf blight under in vitro test. The suspension fo1 mulntion nuxlure of A.6 (B. firmus E 65, P. aemginosa C32b, B. cereus II 14), A8 (B. firm us E65. Serrcrtia 1narcesc1Jns E31, P. aeruginosa C32b, B. c·erous II 14), talc based-A8 and animal compost granul1?·A8 had percentage rnhibition to P. or:yzae of 71.04, 79.19, 63.87 and 66.68%, respectively. P. nerugi11m:1a C32a produced glucanolytic index of 2.26 and specific activity of 0.448 U mg- 1 . In grecnl1ouse Lest, the lowest rnt.ens1ty of neck blast was shown by A6 treatment.. Bentonite formufation show<'d good effeet in suppressing bacterial leaf blight lesion length m greenhouse tesL. ThP <'Pll v:iob1hty deerease was ranged from 2 39 to 18 .30~0 among different bioformulations. Talc-AS based formulaL1on was stable at period of storage shown1g no viability lost. T alc-A5 (Bacilltts /frmus IE65, Pseudomonas aeruginosa C32b) formulation was effective against sheath and bacteriHl lf'af bhghl but showed lower effect on neck blast d15ease rn the field. Further studies should focus on the evaluation of different earners other than talc-based powder as stable and cheaper media. then scale-up possibilities for further apphcal1ons