Monday, September 25, 2023
HomePlant ProblemsBacterial Wilt in Tomatoes: Identification and Prevention

Bacterial Wilt in Tomatoes: Identification and Prevention

Bacterial wilt is a illness that may have devastating results in your tomato crops and throughout your backyard. It will also be simply mistaken for different ailments.

It’s vital to have the ability to establish bacterial wilt, so you may make sure you aren’t coping with a unique concern that requires a unique type of remedy.

Right here, we’re going to talk about easy methods to establish bacterial wilt, variations between different widespread tomato ailments and what you are able to do to stop it in your backyard.

What’s Bacterial Wilt?

Close-up of a tomato plant affected by Bacterial Wilt in a sunny garden. The tomato plant has climbing stems with green compound leaves with serrated edges and a slightly hairy texture. The fruits are round, with a smooth shiny green skin. Leaves and stems are wilted, with gray and brown spots.
Bacterial wilt is a soil-borne bacterial illness infecting crops by soil, wounds, carriers, or contaminated weeds.

Bacterial wilt (typically known as Southern Bacterial Wilt) is a vascular bacterial illness attributable to the bacterium Ralstonia solanacearum (R. solanacearum). It’s a soil-borne illness that may infect crops if:

  • It’s already current within the soil.
  • The plant is wounded throughout transplanting.
  • The disease-causing micro organism can journey simply into the roots and infect the plant.
  • Carriers resembling root-knot nematodes or sure bugs (resembling cucumber beetles) cross paths along with your crops.
  • Close by weeds are contaminated and unfold the illness.

The micro organism inhibits regular water and nutrient uptake by clogging vessels because it multiplies. Ultimately, all of the plant’s vessels are clogged, so it may possibly now not soak up any water or vitamins, in the end resulting in dying.

As soon as crops are injured and contaminated, they start to launch R. solanacearum into the soil. This illness can have lethal outcomes on each younger and mature crops.

Figuring out Bacterial Wilt in Tomatoes

A key distinction between bacterial wilt and lots of different widespread tomato ailments is that micro organism trigger bacterial wilt, whereas a fungus causes many others. It may be simply mistaken for a handful of different ailments, so it’s vital to know what to look out for.


The principle factor to search for is the place the an infection begins. For probably the most half, different tomato ailments start to point out signs on the decrease a part of crops, leaping up from the soil by the use of water splash or passing from plant to plant by foliage touching. In distinction, bacterial wilt exhibits signs first on the high of the plant and works its approach down.

Total well being, age, soil kind, vitamins current, and environmental components play a task in how shortly bacterial wilt can unfold.

In younger crops

Close-up of a young tomato seedling in the garden affected by bacterial wilt. The seedling has a short, pale green stem that is slightly wilted and drooping. The leaves are compound, oval with jagged edges, wilted, gray-green.
Bacterial wilt signs begin on the high of the plant and progress downward, not like different tomato ailments.

Bacterial wilt could trigger a lack of tomato flowers, stunted development, and low productiveness or could trigger the principle stem to wilt and collapse fully, inflicting dying earlier than or shortly after transplant.

In Mature Crops

Close-up of mature tomato plants affected by bacterial wilt in a garden with covered beds. The plant bears clusters of large, oval, juicy fruits with smooth, shiny green skin. The leaves are compound, composed of oval leaflets with serrated edges. The leaves and stems of the plant are wilted, soft, drooping, with yellow-brown spots.
Mature crops in peak season could exhibit wilting and withering of younger leaves close to the highest.

Mature crops may be contaminated or start to point out signs in peak season when your crops are filled with fruit. You’ll discover wilting and withering of the youngest leaves close to the tops of the crops. Leaves on the furthest level from the principle stem may begin wilting first, inflicting you to suspect your plant merely must be watered, making it arduous to diagnose with out expertise. No quantity of water would repair this wilt.

You may even see brown cankers alongside the stem or discover your plant will not be rising above a sure top. Typically root rot will develop close to the bottom of the plant. There might not be any recognizing or discoloration; the plant could wilt and wither away.

Two traits to search for when attempting to diagnose bacterial wilt after crops have perished:

  • Brown decay can be noticeable contained in the stem for those who had been to chop it open lengthwise
  • A milky substance will stream from the reduce web site when positioned in water

What Crops Can Bacterial Wilt Have an effect on?

Close-up of a tomato plant affected by the disease bacterial wilt in the garden against a blurred background. Stems and leaves are wilted, rotten, gray-green in color. Several unripe round fruits with a shiny green skin grow on a branch.
Bacterial wilt can infect varied nightshade crops and decorative flowers.

Bacterial wilt can have an effect on solanaceous (nightshade) crops resembling tomatoes, potatoes, tobacco, eggplant, and peppers, in addition to decorative flowers together with (however not restricted to) petunias, dahlias, marigolds, geraniums, nasturtiums, and zinnias. It’s believed to contaminate about 200 host plant species in over 30 plant households.

When you’ve got the area, attempt planting these crops distant from each other, or contemplate rising some in containers.

Excellent Bacterial Wilt Situations

Close-up of a withered branch of a tomato plant affected by bacterial wilt in the garden against the background of healthy tomato bushes. The stem is upright, slightly hairy, has compound leaves that consist of oval leaflets with serrated edges. The leaves are sluggish, drooping, pale green.
Bacterial wilt thrives in scorching and moist circumstances, notably in Southeastern components of the US.

Bacterial wilt thrives in tropical circumstances when temperatures are at or above 85°, and it develops extra shortly in moist soil. Because of this, Southeastern components of the US are normally at excessive danger of this illness. As soon as current, this pathogen is persistent and quick-moving.

Whereas crops typically recuperate barely at night time when temperatures settle down, they’ll wilt once more the following day when circumstances enhance.

Bacterial Wilt Unfold

Close-up of a woman's hand in a beige glove holding wilted tomato leaves in a greenhouse on a blurred background. The tomato bush has upright hairy stems with complex green leaves and serrated edges.
Bacterial wilt spreads by contaminated crops, water sources, instruments, equipment, and bugs.

R. solanacearum, the micro organism that causes bacterial wilt, is soil and water-borne. It’s not recognized to journey from plant to plant by the use of foliage touching or by wind.

One stage of this micro organism’s life cycle is on a plant’s exterior, but it surely doesn’t elevate a lot concern because it doesn’t survive for very lengthy when circumstances usually are not ideally suited.

Bacterial wilt can unfold in a number of methods:

  • Contaminated crops infect soil, resulting in potential unfold to different crops close by by the use of the foundation system
  • Contaminated water supply, irrigation/rainfall-runoff, or overhead watering
  • Contaminated harvesting instruments and farm equipment
  • Bugs resembling cucumber beetles carry the micro organism of their our bodies after feeding on contaminated crops. As they feed on unaffected crops, they create wounds by which the micro organism can enter and infect the vascular system of the wholesome plant, inflicting an infection.
  • Sadly, some crops can have R. solanacearum current however not present any signs. They’ll unfold the illness with out providing you with a purpose to suspect an infection.

R. solanacearum can stay on natural matter with out a host plant within the soil for days to years.

Plant Disposal

Disposal of tomato plants infected with bacterial wilt. Close-up of a diseased tomato bush lying on the soil in the garden. The plant has withered, drooping green leaves with brown-yellow spots. The stems are soft, rotting, weak, pale green in color. On the bush there are ripe round fruits with a smooth glossy red skin.
Eliminate contaminated crops correctly and keep away from including them to compost piles.

Though you may (and may) take away crops recognized to be contaminated with bacterial wilt, you can not take away the micro organism inflicting the illness from the soil. All you are able to do is take away the contaminated crops and hope your remaining crops are wholesome.

Professional tip: Don’t add contaminated crops to a compost pile, as R. solanacearum might survive within the pile. Throw them away, place them in a plastic bag and depart the bag out within the solar, or burn them the place and if you find yourself permitted to.

Tips on how to Keep away from Bacterial Wilt

Under are some issues you are able to do to attempt to keep away from a bacterial wilt infestation.

Take Care Throughout Transplanting

Close-up of male hands planting a small tomato seedling in the garden into the soil. The seedling is small, has an upright short, slightly hairy stem, and complex green leaves that consist of oval toothed leaflets. An orange garden tool lies next to a freshly planted seedling.
Cautious dealing with throughout transplanting is essential to keep away from small wounds that make crops susceptible to R. solanacearum.

Small wounds attributable to tough dealing with throughout transplanting and basic root breakage may cause crops to turn out to be extra prone to entry of R. solanacearum. As soon as the micro organism have entered by the foundation system, they’ll multiply, inflicting whole blockages of significant vessels, resulting in the lack to uptake water and vitamins. This can result in a plant’s final demise.

Be certain your soil is properly drained, as excessive moisture content material + heat temperatures are perfect for bacterial wilt an infection.

Deter Damaging Nematodes

Tomato roots infected by nematodes. The roots are dense, light brown in color, thin, slightly tangled, and have round and oval irregular formations due to nematode infestation.
Sure nematodes can create entry factors for R. solanacearum by damaging plant roots.

Pest nematodes, particularly root-knot nematodes, may cause harm to the roots of your new crops, permitting an entryway for R. solanacearum. Some consultants consider sure cowl crops planted in fields in the course of the low season and lure crops close to your tomatoes will help deter nematodes.

In northern areas, corn and grains are good choices, whereas in southern areas, crops resembling marigolds, some forms of chrysanthemums, and rapeseed, to call a couple of, might deter nematodes which will trigger bacterial wilt.

You can even attempt resting sure areas of your backyard annually to assist maintain nematodes away. Some consultants consider if there may be nothing there for them to feed on, they could vacate the world or die off fully.

Professional tip: Take into account solarizing the world of your backyard affected by nematodes to kill them off. To solarize, reduce outdated greenhouse plastic or a 6+ mil silage tarp to the dimensions of your backyard and canopy it tightly for a couple of weeks or months. Temperatures of the soil ought to turn out to be scorching sufficient to kill any nematodes current. Do not forget that throughout this course of, you may additionally kill some helpful bugs, together with helpful nematode species.

Supply Crops From Respected Sources

Close-up of many young tomato seedlings in white containers, in a garden center. The seedlings have upright stems with compound leaves that consist of oval leaflets with serrated edges.
As a result of early seed beginning and greenhouse watering, tomato crops from southern states can carry bacterial wilt.

Many tomato crops are transported to northern areas and components of Canada from Southern states (primarily Florida and Georgia) as their local weather permits them to begin seeds earlier. Sometimes these crops are grown in greenhouses which typically function overhead watering. Overhead watering and water runoff are nice for illness unfold.

Additionally, as a result of bacterial wilt is extra prevalent in southern states, it’s not unusual to find transplants from these southern states are contaminated with the illness upon arrival.

It’s a good suggestion to analysis corporations earlier than you buy crops from them. Ask them about their rising practices and preventative methods to be protected.

Hold Gardens Tidy and Instruments Sanitized

Pruning a tomato plant with secateurs in the garden. Close-up of a man's hand cutting tomato stalks with black and green secateurs. The tomato plant has long pale green stems covered with compound leaves with serrated edges and a slightly hairy texture. Small unripe fruits of a round shape with a green glossy skin grow on stems.
Sanitize backyard instruments after pruning to stop illness unfold.

Any time you might be in your backyard to prune, make sure you follow correct sanitizing of your instruments afterward to keep away from any potential illness unfold. Seize a Clorox® wipe or spray your pruning shears with a 70% isopropyl alcohol answer and wipe clear.

Bear in mind, while you prune, you might be wounding your crops, making them prone to ailments. Taking care that your instruments are sanitized after every use ought to provide you with some peace of thoughts when grabbing them for the following pruning session.

You also needs to have a weed suppression plan to your gardens, as a number of weeds can unfold this micro organism to your money crops. Take into account mulching throughout manufacturing and canopy cropping within the low season to assist maintain weeds to a minimal.

Choose Illness-Resistant Cultivars

Close-up of ripe fruits of a Heatmaster F1 tomato in the garden. The fruits are large, round, slightly flattened, with a smooth, hard skin of a bright orange-red color. The stems are green, slightly hairy, the leaves are compound, oval, with serrated edges.
Select bacterial wilt-resistant cultivars by filtering for illness resistance on seed firm web sites.

You may choose cultivars extra resistant or tolerant of bacterial wilt than others. On many seed firm web sites, you may filter for particular illness resistance. Under are a couple of examples of those cultivars bred for bacterial wilt resistance.

Professional tip: Search for seeds which can be indicated as “nematode resistant” or “bacterial wilt resistant.” Pest nematodes may cause harm that opens crops as much as a slew of ailments, bacterial wilt being simply one among them.

Plum/Sauce Invincible
Slicer Florida 7514
Heatmaster F1
Momotaro F1
Powerful Boy F1
Neptune – determinate early, not bothered by nematodes or humidity, nice warmth tolerance
Tropic Boy – indeterminate, tropical selection
Rootstock Armada
Shin Cheong Gang F1
*Proof against the nematodes which might open up your crops to bacterial wilt

Bear in mind that you could be nonetheless expertise bacterial wilt even when rising a resistant cultivar. The resistance bred into these cultivars makes the crops extra tolerable however is not going to 100% stop illness. Additionally, resistant cultivars could produce fruit that’s smaller than anticipated.

Do you know? Rootstocks are bred for illness resistance and may solely be used to graft. When tomato seedlings are reduce and spliced (grafted) to rootstock, the scion (the fruit-producing) selection can produce increased yields, develop extra vigorously, and have elevated illness resistance!

Follow Crop Rotation

Transplanting young tomato seedlings into the garden on a raised bed. Close-up of a woman's hands planting one of the seedlings into the soil. The seedling is lush, has several thin stems with complex leaves, which consist of oval leaflets with serrated edges. A small garden shovel is stuck into the soil next to a freshly planted seedling. Nearby, on a raised bed, there are also many young tomato seedlings in peat pots.
Stop new infections by training crop rotation and avoiding planting solanaceous crops in contaminated plots.

Since R. solanacearum lives within the soil, it is very important follow correct crop rotation to attempt to stop a brand new an infection annually. When you’ve got an contaminated plot, keep away from planting nightshades or solanaceous crops there for no less than 3 years. You possibly can attempt rising in containers for a couple of years when you’ve got restricted area.

In case you develop in pots or raised beds and discover your crops affected by R. Solanacearum, you may and may eliminate the soil and begin recent. Don’t compost or reuse this soil; the illness might be harbored within the compost pile. 

Look Over Your Crops Incessantly

Inspection of a tomato plant for diseases and pests. Close-up of female hands touching unripe tomato fruits and its leaves. The tomato plant has complex leaves consisting of green oval leaflets with jagged edges. The leaves of the plant are slightly wilted, drooping, twisted, with pale green spots. The fruits are large, round, slightly flattened, with a smooth, shiny green skin.
Commonly examine your tomato patch for indicators of bacterial wilt.

Stroll by your tomato patch typically, particularly when circumstances for bacterial wilt are ideally suited. In case you see something suspicious, verify the illness and take motion instantly to keep away from a full backyard infestation.

Variations Between Bacterial Wilt and Fungal Wilt

  Bacterial Wilt Fungal Wilt
Attributable to R. solanacearum Verticillium and Fusarium species
Signs sample Begins on the high and works its approach down the plant Works slowly all through complete plant, creating extra uniform signs
How organism causes wilt Blockage of vessels because of multiplication of bacterial cells causes plant to be unable to consumption water or vitamins Toxins shaped in plant trigger wilting impact
Technique of journey Soil, seed, wind, and water bourne It may be transferred by water, air, foliage, and soil
The way it spreads Enters by the use of root openings or wounds, typically attributable to nematodes Will be transferred by water, air, foliage, and soil

Are Natural Sprays Efficient?

Sadly, at the moment, there aren’t any efficient chemical therapies and no solution to eliminate bacterial wilt as soon as it’s current in your crops. Your greatest wager is to take away the contaminated crops and soil. A couple of biofungicides declare to be efficient in opposition to bacterial strains as properly, however as soon as the micro organism enter the plant, these simply aren’t very efficient.

In case you are rising in a house backyard, your greatest protection is rising resistant cultivars together with good land stewardship and correct sanitation practices. Bigger-scale operations may mix these practices with chemical management (known as built-in pest administration), as there was some success in lowering bacterial wilt utilizing all 3 of those practices.

Ultimate Ideas

Whereas there aren’t any recognized therapies for bacterial wilt as soon as it’s current, you are able to do a couple of issues to maintain your backyard protected from this nasty soil and waterborne illness.

Solely purchase your crops and soil from trusted and respected sources. Do your greatest to discourage root-knot nematodes and different potential disease-carrying bugs. Follow crop rotation, experiment with cowl cropping, burn any contaminated crops, and undoubtedly attain out to your native Extension Workplace.



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