Efficacy of Bacillus siamensis RRK1–Rif wettable powder formulations against sheath blight and dirty panicle diseases and on yield enhancement of rice

Abstract

Baciilus siamensis RRK1–Rif bioproducts as wettable powder (WP) formulation stored for 11 months at room temperature (25-30 °C) significantly reduced sheath blight disease caused by Rhizoctonia solani. At 21 days after pathogen inoculation, the bioproducts effectively reduced sheath blight severity and percent of infected tillers per plant by 36.56-48.82% and 7.94–30.65%, respectively when compared to a pathogen inoculated control. Moreover, these bioproducts also reduced dirty panicle disease on rice plants sown under natural fungal pathogen infestation by 17.02-37.02%, increased the percentages of healthy seeds by 6.05–11.27%, while reduced the dirty panicle infected seeds and empty seeds by 3.29–32.71% and 25.15– 55.11%, respectively. The bioproducts of RRK1–Rif promoted plant growth by increasing the tiller and panicle numbers per plant by 20.38–22.68% and 14.55–15.40%, respectively. The yields were increased by 34.49–45.66%, whereas whole kernels of milled brown rice were increased by 4.95–16.78% and broken kernels were reduced by 13.24–44.85%.