Laboratory, greenhouse and field based assessment of sodium acetate for control of plant bacterial speck disease

View the project final report

• 2008 annual report

Commodities

• Vegetables: cabbages, tomatoes

Practices

• Pest Management: chemical control
• Production Systems: organic agriculture

Pseudomonas syringae bacteria are causal agents of bacterial speck diseases on many crops such as tomato and bean. Conventional control methods such as various bactericide compounds, biological control strains and breeding approaches are not very effective due to the limitations of their uses. Organic growers need better options for dealing with bacterial diseases. Our preliminary results showed that spray of low concentrations of sodium acetate (NaAc, the sodium salt of vinegar) significantly compromised bacterial growth and disease symptom development of Pseudomonas syringae pv. tomato, the causal agent of bacterial speck disease on tomato, suggesting the potential of NaAc as a new method to control Pseudomonas pathogens. To further test the potential of NaAc, there are two objectives in this proposal: 1) We plan to assess and to optimize the NaAc recipes, which include NaAc concentrations, timing of spray and species of pathogens targeted. Preliminary investigation of efficacy of tested recipes will be conducted in the laboratory and greenhouse facilities on the Kansas State University campus in Manhattan, KS. 2) With the conclusions drawn from assessment of greenhouse trials, we will test the optimized NaAc recipes on field trials at the Rocky Ford Research Center Farm in Manhattan and the K-State Horticulture Research and Extension Center in Olathe, KS. Ultimately, we will be able to determine which tested recipes work best against diseases of interest. The success of this research will provide farmers more options in controlling bacterial speck or other diseases and serve as a basis for further research on NaAc recipe as an effective organic bactericide.

This project will begin in October, 2008. There are two phases of this research.

The first phase will be the assessment and optimization of NaAc recipes against bacterial speck on tomato and bean by testing different concentrations of spray (from 0.1mM to 100mM), examining the timing of spray (days and times before or after bacterial inoculation), and testing NaAc application against other bacterial pathogens (such as Xanthomonas on tomato and cabbage). This phase will be finished in laboratory and greenhouse facilities on the Kansas State University campus in Manhattan, KS. Inputs for the first phase will be graduate student labor, laboratory and greenhouse expense for proposed experiments.

The second phase of this project will start in spring of 2009. We will take the optimal NaAc recipes obtained from the first preliminary phase to the larger-scale field trials at the Rocky Ford Research Center Farm in Manhattan and the K-State Horticulture Research and Extension Center in Olathe, KS. Two cropping cycles will be done through the summer and fall of 2009 to ensure good statistical analysis. Inputs for the second phase will include intensive graduate student labor, and collaboration with farmers and plant pathologists. Farmer cooperators will have the chance to join further study as an integral part of sustainable agriculture project.

Outputs:
The major outputs of this proposal are publications on NaAc recipes in control of plant bacterial diseases. The results derived from this research will be included in a Ph.D. dissertation and academic journal articles written by the Mr. Deng. Other outputs will include presentations to interested farmers in meetings and field presentations at the Olathe field station and state and regional vegetable extension meetings. The results of this research will serve as a good basis for further investigations of NaAc as an effective bactericide for vegetables and other crops.