Tomatoes are excellent plants to grow in your garden. Not only do they look gorgeous once they grow and bear fruits, but their fruits are also known for being remarkably nutritious and tasty.
However, growing tomato plants in your own is not without challenges. One of the problems that you may encounter when planting tomatoes is plant diseases.
Plant diseases that affect tomatoes are numerous, and they all bring different dangers to the plant. One such plant disease is called blight.
You can continue reading the article to learn more on blight on tomatoes, their nature, their types, the preventative measures against them, and the best products to counteract them.
- 1 What causes tomato blight?
- 2 The Two Types of Blight
- 3 How to Prevent Blight
- 4 Tomato Blight Cure
- 5 The 6 Best Fungicides against Blight
- 6 Best Fungicides against Blight – Comparison of the Different Active Ingredients
- 7 Summary
What causes tomato blight?
Blight refers to a disease or a group of diseases that are often recognized by the spots on the leaves of the plants that it infects. Blight commonly affects tomato and potato plants.
There are many kinds of plant diseases ranging from bacterial infection to simple physical diseases. Among these, blight is categorized as a fungal infection.
These fungi infect the tomato plant causing the different symptoms of blight. The fungal infections can be life-threatening but, most of the time, the blight only severely limits the yield of the tomato plant rather than outright killing it.
Tomatoes are generally quite vulnerable to many plant diseases. Fortunately, every variety has its own resistance to a particular group of plant diseases. Naturally, there are also tomato varieties that are resistant to blight.
Some of the varieties can be extremely resistant or moderately resistant to blight. If you are not worried about blight, or if it is not common in your location, you can always just pick the tomato variety you want.
Read more: Different type of tomatoes
Blight is actually categorized into two. You can learn more in the next section.
The Two Types of Blight
As mentioned already, there are two different types of blight – the early blight and the late blight. These two types of blight are differentiated by the time of their infection and the fungi responsible behind them.
Early blight refers to the plant diseases caused by the infection of a fungus called Alternaria solani. According to Wikipedia, the fungi Alternaria solani causes the leaves of the tomato plant to have concentric, target-like brown spots with yellowy outer edges.
Even though the disease is called ‘early blight’, it can actually happen at different periods of the plant’s growth. Furthermore, the symptoms actually commonly appear first on old leaves close to the base of the tomato plant.
Symptoms may also appear on other parts of the plant. The stem, for example, can have a collar rot. Collar rot refers to the recognizable lesions or wounds on the stem. If such symptoms appear on a seedling, the seedling may actually rot due to it.
Fruits can have early blight symptoms as well. They are similar to leaves in that they can contain brown target-like spots. However, the ones on fruits appear larger and are spherical in shape.
Early blight can generally appear during humid weather and cool temperature.
While early blight is caused by Alternaria solani, the late blight is caused instead by the water mold called Phytophthora infestans.
Late blight is a much more sinister disease than the early blight. It is more likely to actually kill the plants. In fact, it is largely responsible for multiple events of famine in the world’s history.
Similar to early blight, symptoms of late blight typically appear on the leaves that are lower to the ground. Furthermore, the leaves they infect will also have brown or black spots. However, the spots will start as greenish-spots on the underside of the leaves which makes them harder to recognize.
The spots caused by late blight are more scattered in nature without any pre-defined shape. Moreover, molds can actually appear alongside these spots.
Stems and fruits will also bear symptoms of late blight. Stem lesions in late blights are quite harsh. They can even affect the petioles which connect the leaves to the plant’s main stem. If the infection is severe enough, whole leaf and vine sections can just suddenly fall off.
Fruit spots can appear and will slowly grow bigger. The color may change from green to brown and to darker shades.
How to Prevent Blight
There are many recommended ways of preventing tomato blight. They may not completely eliminate the possibility of blight, but they significantly lessen the probability of your plants contracting them.
Choose your variety
The tomato variety you pick is very important when trying to avoid blight. Some tomato varieties are naturally resistant against them. Hence, just by choosing these varieties, you can avoid a lot of potential problems.
Another choice you can make is to plant determinate tomato varieties that mature fast. Since they mature fast, they are exposed less to foreign elements and are, therefore, much safer.
Read more: Determinate vs indeterminate plants
The fungal infection can occur due to the moisture or wetness of the plants’ bodies. Therefore, controlling the moisture may be necessary to prevent the infection from happening in the first place.
You can choose to water the base of the plant only, not including the body. Furthermore, you can also put mulch on top of the soil. Mulch is a bunch of material that can be used to control the water content near the plant even further.
Manage the space for each tomato plant
Infections such as blight can affect multiple plants. Hence, making sure that each plant is isolated from each other is important. By doing so, whenever a plant is infected by blight, it does not scatter and affect all your other plants.
The easiest thing to do to manage your plants’ space is to simply plant them in large intervals. You have to make sure you take into account the plant growth when measuring the space intervals between plants.
Staking and caging can also help in this regard. Since tomatoes need ample support anyway, using these cages to also contain them and prevent them from touching each other is a good preventative measure.
Another thing you can do is to plant the tomatoes in containers. By doing so, you can move the tomatoes much easier whenever needed.
Learn more: Planting Tomatoes in Pots
Since blights are fungal infections. Agents that can act against fungi are naturally a great option against them. You can apply fungicides on plants to prevent them from contracting blights.
However, fungicides are only used whenever symptoms of early blight appear. Whenever the brown spots appear, you should remove the parts with these spots and apply fungicide on the plant after.
Tomato Blight Cure
You can prevent blights from affecting your plant. However, whenever the tomato plant you are growing is already infected, it is harder to deal with.
For early blights, the method mentioned earlier is applicable. You can simply remove the places with brown spots and apply fungicides immediately after. Hopefully, this will prevent the blight from further affecting the rest of the plant. This is doable since early blights spread slowly.
Unfortunately, for late blights, there is not much you can do. If the infection is still small, you can do the same as with early blights and remove affected areas immediately. There are fungicides that are particularly for late blights and you can apply these to your plant and hope for the best.
However, late blights spread really fast. If you are not careful, by the time you recognize the symptoms, it’s already too late. If the infection is already severe, instead of curing the tomato, you should instead pull the entire thing from the ground to avoid affecting the other plants in your garden.
The 6 Best Fungicides against Blight
Countless fungicides have appeared in the market. This may be a good thing but it also makes finding the most effective fungicides quite difficult.
Therefore, this section aims to help you by recommending some of the best fungicides in the market in tomato blight control.
1. CuPRO 5000 Fungicide
The first product in the list is a copper-based fungicide named CuPRO 5000.
There have been many different fungicides with copper as their main active ingredient. They combine the copper with different substances resulting in the various products that we have nowadays.
As for the CuPRO 5000, it has Copper Hydroxide, Cu(OH)2, as its active ingredient against fungi. The product consists of 61.3% of Copper Hydroxide which makes it very effective as prevention to blight.
In addition to being an effective anti-fungi agent, the product is also a bactericide. This means that it can also prevent bacterial infections.
As you may have known already, blight is only one of the numerous diseases that a tomato plant can contract. Thus, any product that can cover multiple bases at once is a great choice.
You can research about plant diseases that are common in your area. If it happens that bacterial infections are a problem alongside blight, you can buy CuPRO 5000.
- 61.3% Copper Hydroxide active ingredient
- Excellent against blight
- Also a bactericide
- Reliable copper-based fungicide
2. Daconil Ultrex Turf Care Fungicide
Copper-based products are quite popular fungicides. They have been around for a long time and they have already established their reputation.
However, other products with different active ingredients are commonly used as well. A great example of this is the Daconil Ultrex Turf Care Fungicide.
The main ingredient for this product is called Chlorothalonil. Chlorothalonil is an organic compound that is also known for its uses as an agent against fungi. The Daconil Fungicide is quite potent and its composition has 82.5% of Chlorothalonil.
Not only does this product work against fungi, but it also is used in many ways. It can control other things such as mildew, molds, and bacteria.
If for some reason, copper-based fungicides do not work for you, Chlorothalonil-based products like the Daconil are a great second choice.
- Chlorothalonil-based fungicide
- 82.5% of the composition is Chlorothalonil
- Also deals with other plant problems such as mildew
3. Green Cure Solutions GreenCure Fungicide
The GreenCure Fungicide is an excellent antifungal product made by Green Cure Solutions.
This product is slightly different than the other two products before it. This is due to its main active ingredient. The GreenCure Fungicide uses Potassium Bicarbonate as the main antifungal agent.
While Copper and Chlorothalonil are both established substances that are widely used in different agricultural and non-agricultural industries, the use of Potassium Bicarbonate in fungicides is relatively new.
You do not have to worry, however, because the use of the substance has already been approved by the Food and Drug Administration (FDA). Not only that, but recent studies have shown that the substance does have antifungal properties that can also work against blight.
If you are not convinced with this product, you can test in on some easy-to-grow tomato plants. Mini tomatoes, for example, mature quite fast and are easy to manage.
Read more: Mini tomatoes
- Use of Potassium Bicarbonate
- Unique fungicide
- Relatively new
4. Dow AgroSciences Dithane Fungicide
This is yet another unique and excellent fungicide product. The Dow AgroSciences Dithane Fungicide is a Mancozeb product that works great against fungi and other plant problems.
In contrary to the others from this list, the main active ingredient of the product is the Mancozeb. The products with it are a lot less popular than the Copper-based ones. However, they are not any less effective. In fact, it can be used effectively against both early and late blights.
Mancozeb fungicides also have Zinc in their composition. Naturally, the Dow AgroSciences Dithane Fungicide is no exception. Aside from the Zinc, it also contains 15% Manganese. All of these combined work together to fight against fungal infections.
- Mancozeb Fungicide
- Excellent in both early and late blights
- Has Zinc and Manganese
- Less popular than Copper and Chlorothalonil fungicides
5. Alpha Chemicals Copper Sulfate Pentahydrate Powder
This solution from Alpha Chemicals is a powder used to prevent fungi and algae.
This product is unique in this list due to the fact that its main use is not actually as a plant fungicide. You can use it anywhere as long as you are worried about fungi growing there.
As its name suggests, the composition is copper-based with a touch of sulfur and some other substances.
The Copper Sulfate Pentahydrate powder can only be used on tomatoes as a preventative fungicide. Rather than applying directly to the plant, it is best used on the soil before planting the tomato. This should be applied alongside the fertilizers.
Read more: Best Fertilizer for tomatoes
- Composed mostly of the Copper Sulfate Pentahydrate compound
- Excellent as a preventative antifungal powder
- Can be applied to soil before planting tomatoes
6. Greenway Biotech Yellow Sulfur Powder
The Greenway Biotech Yellow Sulfur Powder is an interesting antifungal product. The main reason for this is its main active ingredient – Sulfur.
The top three most used antifungal substances or compounds are actually Copper, Sulfur, and Chlorothalonil. However, this pertains to every industry including the non-agriculture ones.
Sulfur-based products, in particular, are actually used in dermatology more than in any other industry. Even though its antifungal effects have been established for a long time, in agriculture, it is mostly used alongside copper. For sulfur alone to be used as the main active ingredient is not too common.
Hence, if you want to try a new alternative, the Greenway Biotech Yellow Sulfur Powder may be a great choice for you. Like the previous product, it should be applied to the soil before planting rather than to the plant itself.
This product also has additional advantages. For instance, it can actually activate the soil and adjust its pH levels to a degree that is beneficial to tomatoes.
- Sulfur-based antifungal powder
- Relatively uncommon in agriculture
- Can also be used to improve soil
Best Fungicides against Blight – Comparison of the Different Active Ingredients
For agents against fungi, there really is only one main criterion to judge whether you should buy it or not. That is its main substance or ingredient used in its composition.
Here, we list a few of them.
Copper-based products are the most popular among the different antifungal products. It has been around for a long time and is particularly effective for plants against blight.
It is commonly used since it has already been proven to be effective. Furthermore, it does not affect the fruits in any way. As long as you give time between the application of these fungicides and the consumption of tomato fruits, you should be safe.
This is recommended for first-time users of fungicides. They act against early blight and can be used against late blight as well.
If Copper-based products are not working for you, Sulfur-based ones are great choices as well.
Sulfur is usually paired with Copper as agents against fungi in agriculture. However, recently, products that use Sulfur as their main active ingredient have cropped up.
Sulfur does have antifungal properties. However, if you want to be careful, it is better to use these products on the soil rather than on the plant itself.
Potassium Bicarbonate Products
These products are even more of a mystery than sulfur-based ones. They are not as commonly used as the other antifungal products. Despite that, studies have shown that they are effective. Hence, products that use it as the main active substance have also appeared
If you want to explore more with different fungicides, you should try the products with these ingredients.
The fungicides based on Chlorothalonil are also as popular as Copper-based ones. There is not much to say about these ones. If you want another popular alternative to Copper that is also effective against early and late blights, you should buy these.
There are still so many more products with various ingredients. Usually, whenever the product is not based on popular substances or ingredients, they will be less effective. As compensation, they may offer more in some areas and are a lot more versatile. For instance, they may offer more protection against mildew and molds.
There is more risk involved when buying these products but since they may be able to offer a variety of benefits, it may worth trying them out as long as you are careful.
Blight is a serious problem when it comes to planting tomatoes. Fortunately, you now understand different ways on how to control blight. There are no plant problems that cannot be solved with proper prevention and proper care. If you buy the best preventative fungicides for your tomatoes, you can say goodbye to the blight on tomatoes and harvest the fruits of your labor without any problems.