by Matt Gibson
About Bacterial Wilt
Bacterial wilt is a tomato disease that is caused by the pathogen bacterium Ralstonia Solanacearum. It is very common in moist sandy soils and humid environments, such as the conditions of the coastal south of the US. The bacteria resides in the soil and works its way very quickly through the roots and up the stem of the plant.
Bacterial wilt is often the result of a plant being injured, cut, or weakened by insects or wear and tear from handling. When infected, the bacteria builds up and clogs up the stems of the plant, keeping water and nutrients from being able to reach the leaves, effectively killing the plant.
Causes And Symptoms of Bacterial Wilt
The youngest leaves show signs of infection first, and begin to wilt during the hottest part of the day. This often goes unnoticed as the leaves stay green during the infection. Eventually, the wilting will become obvious, but once you notice it happening, it is likely that the entire plant has begun to wilt and will soon die. Bacterial wilt tends to occur when the weather is extremely hot and there is a high level of humidity from recent rainfall, leaving the soil wet. Bacterial wilt is also common in areas with a high soil pH.
Bacterial wilt can be diagnosed by cutting the stem at the base of the plant and searching for discolored tissue. Suspend suspect stems in a glass of water to test for bacterial wilt. Infected stems will ooze a slimy, white substance into the water within minutes of being submerged.
Treatment and Control of Bacterial Wilt
There are no known effective chemical controls for bacterial wilt. As the plants die, the bacterial pathogen is released into the soil, so the most important thing you can do to prevent the spread of bacterial wilt is to remove diseased plants as soon as you notice wilting. Do not compost these plants, but discard them immediately and clean and sanitize any tools used in the removal and disposal process.
So, since there is no way to cure infected plants, the best way to control bacterial wilt is to practice prevention methods. Use good cultural controls to keep bacterial wilt out of your garden and off of your tomatoes. Here’s a few ways that you can prevent bacterial wilt issues:
- Rotate your crops regularly
- Install raised beds
- Space plants out evenly to improve air circulation
- Test soil and amend to a pH of 6.2 to 6.5 for tomatoes and most garden vegetables
- Wash hands and gardening tools after handling infected plants
- If problems persist with soil borne disease, try shifting to container gardening using a sterile commercial potting mix.
Commonly Asked Questions About Bacterial Wilt
What causes bacterial wilt in tomatoes?
Bacterial wilt is a disease caused by the pathogen bacterium Ralstonia Solanacearum and is most commonly found in moist and humid sand-heavy soils. Bacterial wilt, unlike fusarium wilt, attacks the plant from the bottom up. It resides in the soil, and quickly attacks the tomato plant from the roots, working its way up the stem and to the leaves of the plant, causing them to wilt. It is spread by contaminated water, soil, infected plant material, and equipment.
What causes wilt disease?
Wilt is a symptom of plant disease that is due to water loss in stems and leaves, and a result of bacteria, fungi, and viruses spreading to plants.
What does tomato wilt look like?
The first symptoms of tomato wilt appear as fruit begins to mature, including yellowing and browning leaves, stunted leaf growth, and wilting foliage. First signs are the lower leaves of the plant turning yellow. This sometimes occurs only on one side of the plant, or on one side of a particular branch. Yellowing is followed by leaf and stem wilting.
How do you revive a wilted tomato plant?
To quickly revive a wilting tomato plant,
water it immediately. Move the tomato plant if it is anywhere near a walnut
tree, as the walnut tree emits a toxin called juglone, which enters the soil
and can affect surrounding plants. Fertilize the soil before planting tomatoes
and again when it starts to set fruit.
This information does not apply to tomato plants that are wilting due to bacterial wilt. You cannot revive a plant that has been infected with bacterial wilt. The best thing to do when you have a tomato plant infected with bacterial wilt is to dispose of it immediately.
How do you fix wilting tomatoes?
The most common reason for wilting tomatoes is dehydration. A lack of sufficient water can have a tomato plant, and its fruit shriveling up in no time. Make sure you are providing your plant with enough water to keep fruit from wilting. Tomatoes need at least two inches of water per week, be it provided by rainfall or by manual watering.
How do you control wilt disease?
There are many practices you can do to help control and prevent wilt disease. Plant resistant varieties when available. Rotate crops often. Remove any infected plants from the garden immediately upon notice. Clean and sterilize any garden tools used to remove infected plants. Use an insect killer to control garden pests which spread diseases that lead to wilt. If problems persist, try installing raised beds and using new soil. Alternatively, you could try container gardening for your tomato plants. Test and amend to bring soil to a pH range between 6.2 and 6.5. Space out new plants to give each plenty of room in order to promote better air circulation. If you have tried everything and still are having issues with wilt, solarization of your garden beds may be the answer.
Want to learn more about tomato bacteria wilt?
Gardening Know How covers Wilting Tomato Plants
Planet Natural Research Center covers Fusarium Wilt
Today’s Homeowner covers Bacterial Wilt in Tomato Plants
Tomato Dirt covers Bacterial Wilt