Abstract:Industrial seedling cultivation and transplanting in upland cotton (Gossypium hirsutum) is one of the important cultivation technique. In order to understand the interaction of microbial agent and nursery substrates against Verticillium wilt caused by Verticillium dahliae in upland cotton, the nursery substrate mixed with the fermentation broth with 41B-1R was used to nursery the seedlings of Sumian 22 and Zhongmiansuo 41cultivars. The results showed that the nursery substrate mixed with the fermentation broth with 41B-1R strain did not have negative effects on seedlings growth, and the 41B-1R strain had good colonization ability in the roots of seedlings. The results also showed that the colonization of V1070 in the roots of seedlings of Sumian 22 and Zhongmiansuo 41 was reduced and disease index was significantly lower than that in the control. As there was no effective control method for controlling Verticillium wilt, a new approach was provided to control cotton Verticillium wilt in this research.