Liu Y.,Nanjing Agricultural University |
Liu Y.,Guizhou Tobacco Institute |
Shi J.,Guizhou Tobacco Institute |
Feng Y.,Guizhou Tobacco Institute |
And 4 more authors.
Biology and Fertility of Soils | Year: 2013
Bacterial wilt caused by Ralstonia solanacearum is one of the most serious tobacco diseases worldwide. Brevibacillus brevis (L-25) and Streptomyces rochei (L-9) with strong inhibitory effects on R. solanacearum in vitro were isolated from the rhizosphere of a healthy tobacco plant in a severely wilt-diseased field. Pot and field experiments were conducted to evaluate the biocontrol effect of the isolated antagonists alone and in combination with organic fertilizer. In pot experiment, the control efficacy was 92.3-100 % in the treatments applied with L-25 and L-9 alone or together with organic fertilizers. When bioorganic fertilizer containing L-9 and L-25 was applied to the soil in field condition, the control efficacies were 95.4 and 30.0 in the Anhui and Guizhou field plots, respectively. The counts of bacteria and actinomycetes in rhizosphere soil were significantly increased (p ≤ 0.05) under all antagonist applications compared with CK (PR). In contrast, fungal and R. solanacearum densities in the rhizosphere soil applied with antagonists were much lower than the CK (PR) rhizosphere. Combined application of the two antagonists had better effect than single antagonist treatments. The antagonists were more effective when they were combined with organic fertilizer as compared with the antagonistic strains only. These results allow us to conclude that a combination of the biocontrol agents, L-25 and L-9, together with organic fertilizers can effectively control bacterial wilt by affecting soil microbial structure. © 2012 Springer-Verlag Berlin Heidelberg.
Chen Y.-N.,Southwest University |
Zhang C.-H.,Zunyi Tobacco Company of Guizhou Province |
Liang Y.-J.,Zunyi Tobacco Company of Guizhou Province |
Chen Q.-D.,Southwest University |
And 4 more authors.
Chinese Journal of Applied Ecology | Year: 2014
According to the fact that corn straws remain or burned in the field in hilly and mountainous areas of Southwest China, which causes organic matter waste and serious atmospheric pollution, it is necessary to develop an efficient method to compost the corn straws. In the present experiment, corn straws were placed on the landside and land corner for composting with thermophilic cellulous bacteria inoculated, chemical nitrogen and nitrogen absorption agent added, and then covered with polyethylene film (bio-composting). Thereafter, flue-cured tobacco grown in the same land was fertilized with the compost to study the fertilizer effect. The results showed that the temperature in bio-compost increased quickly (over than 35℃ within 2 to 3 days) but decreased slowly compared to natural composting (control). In the bio-compost, temperature over than 50℃ lasted for about 15 days and the number of bacteria was 100 to 1000 times higher than in the control de-spite that microbial groups decreased in the high temperature period. After 90 days of bio-compos-ting, corn straws contained water less than 25% with pH 6.14 and showed brown or black color and fragmental or farinose physical state, indicating good decomposition and humification. Meanwhile, the active organic matter and nutrients, including N, P and K, were significantly increased. The yield, mean price, economical output of flue-cured tobacco leaves were increased and the leaf quality was improved by application of chemical fertilizers plus the compost at the ratio of 1:1. Therefore, bio-composting could utilize efficiently corn straws and eliminate air pollution, which is worth popularization in hilly and mountain areas. ©, 2014, Editorial Board of Chinese Journal of Applied Ecology. All right reserved.