Published Article / A study involving two incubation experiments and a germination experiment in sandy soil was conducted to determine the influence of Multiplied Effective Micro-organisms (M-EM) that were exposed to different levels of irradiation and temperature fluctuation as well as prolonged storage, on the germination and seedling vigour of maize, sorghum and sunflower. Irrespective of poor handling and/or prolonged storage of M-EM, seed treatment with M-EM improved germination under optimal conditions for all crops compared to the control. Increased planting depths and cold stress were used to create conditions where seed treatment with M-EM may improve germination and seedling growth. Seed treatment with M-EM significantly improved germination and seedling vigour of the stress-tolerant maize cultivar following cold stress. Similar improved seedling vigour results were observed for the stress-tolerant sunflower cultivar at increased planting depth. It was concluded that the beneficial influence of M-EM as a seed treatment was remarkable, even after exposure of M-EM to unfavourable environmental conditions and prolonged storage before application. Further research under field conditions and in different cultivation systems are required before the large scale application of M-EM as seed treatment can be recommended.