Quick Answer: Fusarium Wilt of Tomato Plant
Fusarium Wilt of the tomato plant is a common yet very harmful disease caused by Fusarium oxysporumsp. lycopersici. It generally damages the leaves of the tomato plant by making them wilted and defoliated. It affects very young plants and adult plants. It obstructs the vascular system of leaves resulting in yellow leaves. There is no known effective method for controlling the disease however, resistant varieties can manage the spread of infection to some extent.
This is your go-to guide for the Fusarium Wilt disease of the tomato plants.
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- Quick Answer: Fusarium Wilt of Tomato Plant
- What is Fusarium Wilt Disease of the Tomato Plant?
- How Fusarium Wilt Harm Tomato Plants?
- How to Confirm that Fusarium Wilt is Troubling your Tomato Plants?
- Ways to Control Fusarium Wilt on Tomato Plants
- How to Prevent Fusarium Wilt on Tomato Plants?
What is Fusarium Wilt Disease of the Tomato Plant?
Fusarium oxysporum is also called Vascular fungi.
Fusarium Wilt is a fungal disease that usually develops due to the lack of Nitrogen and Potassium [macronutrients]. The growth of fungus starts from the bottom of the leaves and later turns the vascular tissues brown and hollow, resulting in the death of the leaf.
It requires warm temperatures and low soil moisture content for the fungal spore’s survival and completion of its life cycle.
Fusarium fungi live in the soil and infect the plant through their roots. It is this ‘ root passage’ that permits the fungi to develop further and affects the vascular tissues of the plant.
The characteristic feature of fusarium wilt is that it causes leaves to turn yellow and conducting vessels to brown.
Fusarium Wilt is a deadly disease; it affects the conducting vessels of tomato plants and causes the death of the plant.
It affects the roots of very young plants and adult plants. Fusarium Fungi also affect seedlings of tomato plants.
How Fusarium Wilt Harm Tomato Plants?
Fusarium wilt disease of the tomato plant is a soil-borne pathogen that thrives in nutrient-deficient environments. It is more likely to be favored by warm temperatures below 80 degrees Fahrenheit.
The other conditions causing the fungi to spread are –
- High Moisture content [High humidity]
- Dry weather
- Acidic ph [5-5.6]
- Nematodes [Root nodules]
The fungus can live in soil without a host for years. It directly attacks the roots of the tomato plant from underneath and spreads throughout the plant.
After infecting the roots of the tomato plant, it reaches the xylem tissue [water and minerals conducting system of the plant] and blocks the tube and vessels of xylem tissue resulting in the brown and hollow appearance of the stem from inside.
Due to this xylem blockage, plants do not get enough nutrition and show signs of deprivation – yellowing and wilting of leaves.
Eventually, leaves fall off, and seedlings die.
Fusarium fungi can contaminate fresh and healthy soil by infecting seeds, leaves, or stems. This infected soil now acts as the source of infection for other healthier plants.
How to Confirm that Fusarium Wilt is Troubling your Tomato Plants?
The Fusarium wilt of the tomato plants is identified by the yellow color and wilting of the tomato leaves. This is known as chlorosis. Chlorosis occurs due to damaged and compacted roots.
A dark brown and hollow inner segment of stems indicates the last stage of the disease cycle. After this stage, tissues die, the stem wither and the plant dies.
Other identifying Symptoms of fusarium wilt found on different parts of the tomato plant are-
- Fusarium initially affects the leaves of one stem only.
- The bottom of the leaves becomes yellow [chlorosis].
- This infection later spreads to other leaves of the same stem.
- The stem starts to develop yellow and then wilt.
- This yellowing intensifies and causes necrosis of leaves [ death of leaf tissue].
- Yellowing and Wilting further spread to other leaflets and stems, causing them to desiccate.
- This yellow color and wilting of the stem indicate that the tomato plant is infected morphologically.
- Anatomically, scraped stems show hollow, dark brown vessels. These vessels are vascular tissues of the tomato plant and are responsible for conducting food, water, and other important elements.
Tomato plants infected with Fusarium wilt show stunted growth. The quality and quantity of the tomato plants are also reduced significantly.
Check this video to find out more about Fusarium wilt-
Ways to Control Fusarium Wilt on Tomato Plants
Fusarium wilt is an incurable disease of the tomato plant. It is almost impossible to eradicate it, however; we can always try to control its spreading.
1. Using Resistant Varieties of Tomatoes
The most effective control method of fusarium wilt is ‘Using Resistant Varieties.’
Fusarium wilt disease has been an infection of concern for a long time. Many commercially available resistant seeds deliver 70-80% protection against fusarium wilt.
If the tomato variety label includes the letters VFN that means it is effective against Fusarium wilt.
However, none of the resistant varieties claims to be 100% effective against fusarium, and they might develop symptoms in the later stage of growth.
2. Use Nitrogen-based Fungicide
The root cause of infection by Fusarium fungi is a high amount of Nitrogen and lack of Potassium.
The use of Nitrate-based fertilizer has been proven effective in the management of the disease. These fertilizers provide essential nutrients to plants and check pathogen growth.
Always spray the fungicide in accordance with the instructions written on the label. Excessive Nitrate-based fertilizer affects the growth of Fusarium fungi positively.
A fungicide containing a combination of Benlate, Difolatan, and Indofil Z-78 is the most effective fungicide for reducing disease.
Check out this video on how to use fungicide for fusarium wilt –
3. Keep Nematodes in Check
Tomato plants are susceptible to Root-Knot Nematodes, which are microscopic and bind to the roots of the tomato plant, making them more susceptible to fusarium wilt.
These are found in soil.
It becomes mandatory to keep a check on their populations beneath the soil.
4. Sterile Soil Planting Medium
Many commercially available soil packets are sterile,i.e., they have undergone procedures of heat or chemical processing and are significantly less likely to develop the infection.
A tomato plant can be grown in containers wherein the added soil is sterilized or healthy\new.
5. Mulching of tomato plant
A low range of temperature restricts the growth of fungus.
Mulching your tomato plant by using either organic matter or plastic sheets will help you in reducing the temperature of garden soil by putting a check on the growth of fungi.
Check out this video on how to mulch and raise beds for the tomato plant –
6. An increase in ph range to 6 or 6.5
An increase in pH can also help in controlling of fusarium wilt disease.
How to Prevent Fusarium Wilt on Tomato Plants?
We cannot control disease development, but we can always take care of our plants and restrict the further spreading.
Prevent your healthy tomato plants by following the steps-
- To begin with, remove the infected leaves, stems, roots, and fruits as soon as possible.
- Prevent wetting of foliage.
- Disinfect gardening tools in bleach and water solution.
- Disinfect your shoes, and hands before touching new plants.
- Be gentle with your plants. Do not cultivate them using any hoe or cultivator.
- Maintain soil pH [below 7].
- Keep tabs on your garden soil.
- Install raised beds with clean soil.
- Avoid excessive nitrogen use.
- Do not work with your plants when they are wet.
- Do not work with injured plants.
- Burn all the infected plants.
- Sterilize your soil before harvesting new tomato plants
- Rotate your crop every 3-4 years.
Disease-resistant seeds labeled with VFN.
Varieties are resistant to race 1 and race 2 of Fusarium Wilt.
Overwatering leads to the over-wetting of leaves which can provide suitable environmental conditions for fusarium fungi to thrive.
Yes, overwatering can do some serious damage to your plants.
No, the complete recovery of tomato plant from fusarium disease is not possible, however you can prevent its spreading in future by doing some basic measures.
Fusarium oxysporum lives for about 5-10 years in soil. It does not require host for living and is a saprophyte.
Yes, you can eat tomatoes with Fusarium. Fusarium infects plant tissues and not the fruit. It is a plant pathogen and does not cause any harm to humans.
I hope this guide will help protect your beautiful tomatoes from Fusarium Wilt Disease.
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