Studies | Unique Samples per Visibility Status | Public Samples per Data Type | Users | Jobs |
---|---|---|---|---|
public: 832 private: 176 sandbox: 2,796 submitted to EBI: 915 |
public: 414,915 private: 120,668 sandbox: 609,225 submitted to EBI: 344,998 submitted to EBI (prep): 399,820 |
16S: 377,729 18S: 12,149 ITS: 14,649 Metagenomic: 68,280 Full Length Operon: 803 Metatranscriptomic: 26,395 Metabolomic: 1,545 Genome Isolate: 1,131 |
14,738 | 856,087 |
Anaerobic Soil Disinfestation (ASD) is a chemical-independent approach to manage soilborne phytopathogens. While it has been demonstrated that ASD can suppress phytopathogens in vegetable cropping systems, it has not been examined for control of tree-crop diseases. We examined the potential of ASD to manage soilborne populations of Agrobacterium tumefaciens and Pythium ultimum under walnut nursery conditions and compared the efficacy of ASD with the chemical fumigant Telone-C35. Mesh bags of sterile field soil inoculated with either A. tumefaciens or P. ultimum were buried in the first of two trials at 7.6 and 15.2 cm soil depths and in the second trial at 15.2, 45.7, and 76.2 cm soil depths prior to ASD or fumigation treatments. After one week of ASD, populations of both phytopathogens fell below detection limits at 7.6 and 15.2 cm soil depths. After completion of the six-week ASD treatment or 4-week post-fumigation, populations of A. tumefaciens remained below detection limits at 7.6 and 15.2 cm depths, were significant reduced compared to no-treatment control soils, and and were not significantly different from populations in the fumigation treatment. A. tumefaciens populations were also significantly reduced compared to no-treatment control soils in both ASD and fumigation treatments at the 45.7 and 76.2 cm depths. Pythium ultimum populations dipped below detection limits after ASD treatment at 7.6 and 15.2 cm soil depths, and were significantly lower than no-treatment controls at the 45.7 cm depth. The bacterial community composition of ASD-treated soils also was significantly different as a function of soil depth. In addition, the effect of ASD on the bacterial community composition persisted with time, as evidenced by the fact that the bacterial composition remained significantly different compared to the no-treatment controls 4 months after ASD treatment. The documented ASD-induced changes in the soilborne bacterial communities may have contributed to the population reductions observed for both A. tuemfaciens and P. ultimum. ERP014920