PURPOSE:To massively produce a microorganism herbicide effective for controlling Eleocharis kuroguwai Ohwi which is a strongly injurious weed in paddy fields. CONSTITUTION:Nimbya scirpicola-K-004 (FERM P-11495) is cultured in a liquid medium at an initial pH of 7.5-10, preferably approximately 8, at 18-35 deg.C, preferably 20-27 deg.C, (for 6-8 days for a vibration culture, or for 4-6 days for an aeration culture), and the produced bacterial cells are fractionated with a homogenizer, a single refiner, etc., to provide the microorganism herbicide for controlling the Nimbya scirpicola-K-004. As the liquid medium, there is used a medium properly containing a carbon source, a nitrogen source, inorganic substances and required growth and production-stimulating substances which can be utilized by the K-004 bacteria, and further validamycin A preferably in a concentration of 10-1000ppm.
