Efficacy of Bacillus subtilis MBI 600 Against Sheath Blight Caused by Rhizoctonia solani and on Growth and Yield of Rice

• Published in: Rice science Vol. 19; no. 1; pp. 55 - 63
• Main Authors: VIJAY KRISHNA KUMAR, K., YELLAREDDYGARI, S. KR, REDDY, M.S., KLOEPPER, J.W., LAWRENCE, K.S., ZHOU, X.G., SUDINI, H., GROTH, D.E., KRISHNAM RAJU, S., MILLER, M.E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2012; Department of Entomology & Plant Pathology, Auburn University, Auburn, Alabama 36849, USA & Acharya N G Ranga Agricultural University, Hyderabad 500030, India; Texas A & M University, Agri-Life Research & Extensian Center. Texas 77713, USA; Andhra Pradesh Rice Research Institute, Maruteru, AP 534122, India; International Crops Research Institute for the Semi-Arid Tropics(ICRISAT), Hyderahad 502324, India; Rice Research Station, LSU AgCenter, LA 70578, USA; Department of Entomology & Plant Pathology, Auburn University, Auburn,Alabama 36849, USA; Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA
• Subjects: Bacillus subtilis; MBI; plant growth-promoting rhizobacterium; Rhizoctonia solani; rice; sheath blight; 产量损失; 单株分蘖数; 枯草芽孢杆菌; 水稻生长; 水稻纹枯病; 积分处理; 粮食产量; sheath blight; Rhizoctonia solani; rice; Bacillus subtilis; plant growth-promoting rhizobacterium
• ISSN: 1672-6308; 1876-4762
• DOI: 10.1016/S1672-6308(12)60021-3

Rice sheath blight disease （ShB）, caused by Rhizoctonia solani, gives rise to significant grain yield losses. The present study evaluated the efficacy of Integral, the commercial liquid formulation of Bacillus subtilis strain MBI 600, against rice ShB and for plant growth promotion. In greenhouse studies, four log concentrations of Integral （from 2.2×10^6 to 2.2×10^9 cfu/mL） were used as seed treatment （ST）. After 25 d, seedlings were dipped （SD） into Integral prior to transplanting. At 30 d after transplanting （DAT）, leaf sheaths were inoculated with immature sclerotia of the pathogen. At 45 DAT, a foliar spray （FS） with Integral was applied to some treatments. The fungicide control was 50% carbendazim at 1.0 g/L, and a nontreated control was also included. Overall, there were 10 treatments, each with five replications. ShB severity was rated at 52 DAT, and seedling height and number of tillers per plant were rated at 60 DAT. In 2009, two field trials evaluated Integral at 2.2×10^8 and 2.2×10^9 cfu/mL. Integral was applied as ST, and seedlings were produced in a nursery bed. After 32 d, seedlings were treated with Integral as SD and transplanted into 10 m^2 blocks. Foliar sprays were given at 45 and 60 DAT. There were seven treatments, each with eight replications arranged as a factorial randomized complete block design. At 20 DAT, the plots were broadcast inoculated with R. solani produced on rice grains. Seedling height before transplanting, ShB severity at 90 DAT, and grain yield at harvest were recorded. Integral at 2.2×10^9 cfu/mL provided significant increase of seedling heights over other treatments under greenhouse conditions. The Integral treatments of ST ＋ SD ＋ FS at 2.2×10^9 cfu/mL significantly suppressed ShB over other treatments. In field studies, Integral provided significant increase of seedling height in nursery, and number of tillers per plant, compared with the control. ShB severity was significantly suppressed with higher concentrations of Integral compared to lower concentrations. Grain yield were the highest at an Integral concentration of 2.2×10^9 cfu/mL. Overall, Integral significantly reduced ShB severity, enhanced seedling growth, number of tillers per plant and grain yield as ST ＋ SD ＋ FS at the concentration of 2.2×10^9 cfu/mL under the conditions evaluated.