Changes of Bacillus subtilis SA-15 in the Diluted Solution Mixing with Microbial Fertilizer and Pesticides

Young-Sun  Kim1,2   Geung-Joo   Lee*3   

1Division of Life & Environmental Science (Horticulture Major), College of Natural and Life Sciences, Daegu University, Gyeongsan 38453, Korea
2Institute of Natural Sciences, Daegu University, Gyeongsan 38453, Korea
3Department of Horticultural Science and Department of Smart Agriculture System, Chungnam National University, Daejeon 34134, Korea


This study was conducted to evaluate the mixing properties between pesticides and microbial fertilizer containing Bacillus subtilis SA-15 by investigating viable cell count (VCC) in the solution. The concentration of pencycuron, tebuconazole, flutolanil, fenitrothion, and chlorpyrifos-methyl was 250, 125, 150, 500, and 200 mg L-1, respectively, and the concentration of microbial fertilizer added to their solutions was 1 g L-1. As compared to VCC of control in the solutions blending with pesticides and microbial fertilizer, pencycuron, tebuconazole, fenitrothion, and chlorpyrifos-methyl were not significantly different, and that flutolanil was decreased. Compared to pesticide formulation, VCC of B. subtilis SA-15 was decreased at tebuconazole EC after treating 4 hours, and at fenitrothion WP after treating 24 hours. These results indicated that microbial fertilizer containing B. subtilis SA-15 couldn’t apply with flutolanil, and might apply with fungicides such as pencycuron and tebuconazole, and with insecticides such as fenitrothion and chlorpyrifos-methyl.

Figures & Tables

Fig. 1. The inhibition of mycelial growth of three turfgrass pathogens by SA-15. The B. subtilis SA-15 was steaked on side of the potato dextrose agar (PDA) plate, and 48 h after incubation at 25℃ mycelia disk (φ 5 mm) of Rhizoctonia solani AG 2-2 (III B) was placed 25 mm distant from the antagonistic microbes, 72 h after incubation at 25℃ mycelia disk of R. solani AG 2-2 (IV), and 96 h after incubation at 25℃ mycelia disk of Sclerotinia homoeocarpa . Inhibition rate (%)=mycelia length of SA-15/ mycelia length of control×100.