leaf spot on potatoe leaf

How To Remove Leaf Spot From Strawberries, Tomatoes, Celery And Passion Fruit Using Copperoxychloride Demildex

Leaf spot is a very common plant disease that even the most conscientious gardener is expected to see at least once in their vegetation. They are caused by a wide range of fungal species, as well as, some bacteria. Regardless of what the causative agent is, the prevention and treatment involve about the same practices.

The symptoms of plants affected by bacterial leafspots are numerous, with variable coloration the most common and first noticeable symptom. Infected plants are usually seen with black or brown water-soaked spots on their foliage or in some, a yellow halo which is usually uniform in size. Generally, the spots increase in size and grow into each other in the rainy season or under wet conditions as the case may be. In dry conditions however, the spots appear speckled.

As the spots grow in number, the entire leaf might become yellow, wither and drop from its branch. The most susceptible plants to bacterial leaf spot are members of the Prunus family which include almond, cherry, plum, apricot and peach. The fruit of these trees would usually have spots or sunken brown portions. These aren’t the only crops vulnerable to bacterial leaf spot. Vegetable plants like tomato and pepper crops are also at risk.

leaf spot infection
diseased affected leaf

Fungal leaf spots on the other hand attack lettuce and some other vegetable crops like (broccoli, cauliflower, tomatoes, peppers and turnips). They are caused by pathogenic fungi. Once the fungi gets into the leaves of the plant, they continue to grow until the leaf tissue is destroyed. Its resulting spots varies in size, from as small as a pinhead spot to one that covers the entire leaf. The dead sections on the leaves of the plants are usually of the colors, tan or reddish, brown or black. In some rare cases, the border of the leaves could turn red or purple. They are generally found in flowering plants and even indoor potted plants.

Leaf spots are most active under moist conditions and warm temperatures, for example, during the summer months. During this period, especially if the plants are being watered by an overhead sprinkling system, there’s just enough moisture to promote infection when the bacteria is either splashed by water or blown on to leaves by wind. Rain and wind are the main culprits for the transmission of the bacteria from plants to plants.

Effects of Leaf Spot

The Leaf spot disease can have a huge effect on the productivity of plants and their overall well-being. To start with, leaf spot can cause lesions in trees and vegetable plants which in turn causes heavy defoliation as the disease further develops.

It also leads to lower productivity in plants as defoliation of leaves might interrupt the photosynthetic processes of the infected plant.

Leaf spot is generally not harmful to older plants, in younger plants however, the disease can spread really quickly and can make the plants wilt and in more infected plants can die.

leaf spot effects

Prevention and Control

There are a number of preventive measures you could apply to prevent the spread of leaf spot in your tomatoes, strawberries, celery and passion fruit gardens. The following are some of them:

Planting resistant varieties: Planting resistant varieties is a very effective way of preventing leaf spot in the aforementioned fruits and vegetables. It is important that you plant resistant varieties of each crop where possible as this will limit, if not completely thwart the development of leaf spot diseases in them.

Cleanliness: Keeping the soil under your fruit tree and the surrounding environment of your vegetables clean is one way to prevent the development of leaf spot disease. Regularly rake up fallen fruits and weed your gardens to prevent leaf spot and other fungal infections in general.

Gardening: Pruning your plants or staking it to improve air circulation can go a long way to prevent leaf spot disease. Improving air circulation starves the causal organism of moisture which it needs for its growth. While it is important to prune the plants, it is equally as important that you use only disinfected pruning equipment after each cut.

Mulching: Having cleaned the plant’s environment, it is now time to use a thick layer of mulch to cover the soil. Mulching the soil will not only tame the aggressive growth of weeds but prevent the disease pathogen from splashing back up onto the leaves of the plant.

Disease-free seeds: Since leaf spot in vegetables is mostly championed by the planting of infected seeds or diseased transplants, care must be taken to ensure that these seeds are from a leaf spot free-stock

Isolation: You should isolate infected plants from others before treatment to prevent the spread of the disease.

Tomatoes get sick by late blight

Other preventive measures include:

  • Keeping plants dry. It is recommended that you wet your fruit and vegetable crops in the morning so as to give ample time for the sun to dry the plants before night fall.
  • It is also important that you do not overwater your plants. If you do, you might be encouraging the spread of the disease as its causal organisms thrive best under moist conditions.
  • You should also keep your plants healthy so they are in the right shape to fight fungal invasion and indeed, any other disease. Early intervention and treatment of plants that appear dry or wilting could help them survive leaf spot if infected by it.
  • For indoor plants, care must be taken to water the roots rather than the leaves. You should avoid watering the leaves especially if your potted plant are kept in a warm and humid room.
  • You should keep your plant’s surrounding free from dead leaves and twigs. This is especially true of they have previously been infected by leaf spot from the plant.

In general, sanitation and water management are arguably the most important preventive measures for containing leaf spot disease. For water management, watering in the morning is best practice. You should also increase air spacing between plants by increasing the spacing between them, and perhaps, most importantly is making sure bigger plants are not shading smaller plants or blocking them from getting enough air.

leaf spot


Although there is no cure for bacterial leaf spot, the following organic measures can be used to prevent its spread.

Baking soda solution: You could spray the infected plants with a baking soda solution. The baking soda solution is formed by mixing baking soda with two and half tablespoons of vegetable oil, a teaspoon of liquid soap and one gallon of water or in some cases, neem oil as an alternative. Care must be taken not to use neem oil when pollinating insects like bees or other beneficial insects are present. Since baking soda can burn some plant leaves, you should only spray a few and then wait for an accompanying reaction. If no reaction is noticed, you can then proceed to apply every two weeks.

fresh vegetables

Treatment Using Copper-Based Fungicides

Applying copper-based fungicides and sulfur sprays can go a long way in thwarting the spread of leaf spot disease. They do not necessarily kill leaf spot but prevents its spread by stopping the spores from germinating.

A good copper-based fungicide for this purpose is copper oxychloride Demildex, which is a fungicide used to stop the spread of fungal infection in plants especially in celery, passion fruits, strawberries and tomatoes.

It does this by interfering with the enzymes of mycelium and spores, consequently causing damage and forming a chemical envelope to fight against fungal intrusion or attack.

The benefits of copper oxychloride Demildex include:

  • Its excellent manufacturing process ensures a reduction in the volume of copper chloride contained in the end product.
  • It is highly effective with inhibiting and preventing the growth of bacterial and fungal spores in plants.

The fungicidal and antibacterial properties of copper oxychloride is down to the copper which slowly dissolves in the moisture present on the plant leaf. This dissolution generally occurs in the presence of weak organic acids, as plant infections take place under moist condition or rainy periods, little amount of copper gets released onto the plant to either kill or inhibit the growth of fungal spores and micro-organisms.

Bear in mind that you can also apply it to surrounding areas – rather than only plants leaves –  to prevent the spread of the disease. It is also important that you begin the treatment as early as possible. If melting out has begun already or the leaves are completely wilted, it might become even more difficult to control.

If your copper oxychloride Demildex application doesn’t give you very effective results or doesn’t do as much as you would have wished, you can apply it once again in the spring to prevent the disease from returning in the more humid seasons.

copper oxychloride demildex used to treat black spots on roses