| | We are globally connected and that is the price you pay. Tomato seedlings which came from a propagator from B.C., showed signs of bacterial disease which had been diagnosed by a lab in Holland as bacterial canker. This disease has been known to us since early 1980, but has not been seen for the past two decades. It is caused by a bacterium Clavibacter michiganensis pv. Michiganensis. The origin has been traced to seed infection from Bolivia, where tomato seeds were produced by the company. So, here is the story that seeds of tomatoes, produced in Bolivia, grown in B.C., under controlled conditions, and seedlings coming to Alberta, were infected by this bacterium. This is in spite of the fact that all companies involved did all due diligence, by screening the seeds, following all sanitation practices.
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It was very heartening to note that these companies did get together with Alberta growers and talked about the diseases, how it happened, and what the future course of action was. This is a very good, open and honest approach, and let us hope that we can learn from the experience of tomato growers from B.C., Ontario and Holland.
The important fact to understand is that the disease symptoms are appearing when you have just started to pick, and your suppliers are expecting certain volumes, at certain times. It is just not a simple disease in your greenhouse, it is going to become a big marketing issue. At this time it appears that tomato variety Bizar is showing the symptoms of bacterial canker. Not all tomato growers who bought seedlings from this propagator from B.C. are showing the symptoms. Symptoms can appear at young seedling stage and on mature plant leaves, stems and fruits. I have colored pictures with me, if any grower needs them, please let me know.
One of the questions being asked is, at what stage should I get rid of my crop, clean my greenhouse, and plant another crop? I think that decision has to be made by you. If you are finding daily that new plants are showing infection and your revenue is not supporting your expenses, then it is time to terminate the crop. But, the question is, if all growers plant a crop of cucumbers, and come into the market at the same time, what will happen? Cucumber price is already the lowest I have ever seen—below $4.00/dozen. Probably staggering your cucumber crop may be the answer. Check with your insurance to see if it covers business losses due to crop diseases.
In the meantime, you should know about this disease. Some information was provided at the meeting by these companies. You can learn more from the following website: http://www.agf.gov.bc.ca/cropprot/bactcanker.htm
Once bacterial canker is confirmed:
Immediately:
- Remove infected plants and adjacent plants carefully.
- Place infected plants in plastic bags to reduce spread, and remove from greenhouse.
- Do not reuse coir or bags from any infected plants.
- Disinfect pruning tools promptly.
- Wash hands well, and change clothing, after infected plants are removed (wash clothing before wearing them again).
- Limit the traffic in the areas where infected plants were found. Work with plants in the infected area last, or assign certain workers to this area.
- Monitor the crop carefully for disease. Pay close attention to plants in the proximity of the initial outbreak.
- Stop recycling water, or start using bleach or hydrogen peroxide or ozone, to treat your water.
Prevention for the following growing season:
- Thoroughly clean the greenhouse after harvest. Remove plant material, clean all greenhouse surfaces, and disinfect irrigation lines.
- Examine transplants before planting. Plant only healthy seedlings.
- Reduce possible sources of soil or moisture contamination.
- Install a foot bath with a disinfectant at the greenhouse entrance.
- Disinfect pruning equipment.
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