apple with scab disease which could be cured with copper oxychloride

How to Prevent Scab on Apples & Pears?

Like blight for potatoes and black spots on roses, scab on apples and pears can render an entire growing season’s crop unsellable. Prevention of scab can be achieved using Demildex, available exclusively from African Pegmatite.

Introduction To Apple And Pear Scab

Apple and pears scab are serious diseases which can cause infections and can destroy the young and emerging leaves badly. This is a problem which is occurring everywhere in the world wherever apples are being grown and cause a major loss for growers as compared to any other disease which can affect apples. It is often reported that around 70% of all fungicides used on apple crops are expressly intended for the prevention of scab. Scab in many cases is mostly superficial - a discolouring of the skin, providing fruit which is less visually appealing. In worse cases, scab and its related phenomena can lead to fruit falling from trees prematurely, the cracking of skin which can lead to spoiling or rotting during storage, and other detrimental impacts. These factors combined can easily lead to a fruit crop that is unsellable, as many commercial buyers will select only the best crop examples to sell in their stores. Fruit producers may be operating on tight margins, and whilst complete crop failure is highly unlikely, a crop that cannot be sold can prove fatal for some businesses operating on narrow margins. As farming is already highly affected by climate and weather, fruit producers will seek to remove the possibility of scabbing as a variable as best they can.

What is scab apple disease on apples & pears?

Apple scab is a disease that is produced by the fungus, “Venturia inaequalis”. The fungus is transmitted by airborne spores that can survive the winter with fallen leaves.Moist and warmer conditions in the spring cause the release of V. inaequalis’s spores which land on the surface of a tree, where a germ tube is formed through the plant’s cuticle. At this stage, a fungal mycelium forms, asexually producing more spores. These spores germinate on the plant, asexually producing more spores. Secondary infections then persist through much of the rest of the growing season.

In this disease, you can see prominent scab marks can be observedon the leaves of apple trees. These marks normally appear from mid-spring normally and stay until the time leaf falls in the Autumn.

hand holding two apples with scabs
pear with scab not treated with copper oxychloride

Scab is a serious kind of disease which is not only limited to apple trees but can also attack some other trees such as Pyracantha, Sorbus, and Cotoneaster. A closely related fungus attack can also happen on pear plants which is also known as pear scab. This normally affects multiple pear varieties from ornamental and through to fruiting.

Scab can cause fruit and leaves loss because of untreated surface blemishing of leaves and fruits. It is mostly being caused in the areas where early summer and spring seasons are cool and moist. Fungal spores are carried by the wind or rain to the leaves, fruits, and flowers from the ground, with newly opened leaves and flowers are more susceptible to this problem.

What does it do to apples?

Apple and pear scab is not only going to impact the fruit surface but in serious conditions, scab can also cause cracking and distortion on the fruit surface which can damage the growth of the fruits in an unsavable way. Scab can put the pears and apples at high risk of developing multiple brown rots on them. However, the mild attack of the scab on the apples is superficial and will not significantly affect the quality of eating fruit. While a scab attack on the apple trees has the ability to result in misshapen and small fruits and can affect the storage quality of the fruit too. At the places where scab is affecting young shoots, it is possible for blistering and puckering to occur. One of the effects of scab is that leaves may turn yellow and will then drop permanently. As a result, scab can also weaken the structure of the tree.

Cracking is caused by restricted expansion of the skin, itself caused by the browning and/or blemishing and is characterised by the appearance of fine lacerations across the surface of the fruit and/or bark. As cracks are essentially ‘open wounds’, the presence of cracking will lead to an increased chance of the fruit rotting during storage via increased likelihood of oxidation and also as an entry point for bacteria or other living organisms. Additionally, cracking may provide for the ingress of Neonectria ditissima and causes apple canker, a fungal disease affecting the bark of the tree which results in the death of the affected branch and thus the associated loss of fruit.

apple with scab that should have been treated with copper oxychloride

What causes scab disease on apples?

Normally, apple scab is caused by the fungus Venturia inaequalis, which is related to Venturia pirina fungus which is responsible for scab on pears. Despite being caused by different pathogens, the epidemiology and symptoms of both diseases are quite similar for both pears and apples. On the flower stalks, the scab will develop as black patches. These dark patches can soon cover the entire flower and will lead to death. However, on the leaves, this disease will cause brown and dark green spots and in severe cases, it will cause a permanent fall of the leaves. On the fruit's surface, brown or black scabs will appear when the fruit is young. As it starts to mature scab will lead to a distortion in the fruit shape and will cause skin cracking. This can also provide an entry point for the various other diseases and will lead to severe loss.

Prevention Of Scab Disease On Apples And Pears

Although choosing a more resistant variety of trees can be an effective option to choose, it is also important to eliminate the current infection in a more effective way too.

Non-chemical means of treatment are limited to manual removal of affected fruits, leaves and shoots. Removal via this method will result in less fungus being available for the next growing season, however unless the trees are well isolated from each other, this treatment is of limited value owing to how easily the fungus is transmitted by the wind. As such, chemical means of treatment are preferred by the commercial grower. Copper oxychloride Demilidex is a highly effective fungicide supplied by African Pegmatite for the control of pathogens like Venturia inaequalis.

apple orchard

What is copper oxychloride?

Copper oxychloride Demildex® is one of the most amazing bactericide and fungicide which can be used to protects plants from infections in the best possible way. Although the excess amount of copper in the plants has the ability to cause physiological alterations which may lead to productivity loss in various crops but most amazingly, cupric fungicides have the ability to be used to treat the fungi attacks in a highly effective way. Copper oxychloride fungicide can be used to treat brown and black spots which can be found in fruits and leaves of apple trees which are suffering from scab disease.

Demildex is a formulation of copper oxychloride specifically tailored to agricultural production. Copper compounds are known for their antimicrobial properties. During the production of Demildex, heavy metals such as lead can be reduced by eliminating copper joiners from the process. Excess heavy metals can have a detrimental effect on plant growth.

How it is used to treat the problem?

Copper oxychloride Demildex is applied in aqueous solution at up to 0.25 volume % (2,500 ppm), which represents an equivalence of approximately 50% metallic copper. Demilidex is applied at the early green tip stage on apples and the early to advanced green tip phase for pears.

Demilidex is supplied as a fine light green powder containing copper oxychloride at a concentration of 850 g kg-1. Copper oxychloride is the sole active ingredient. Particle size is 40% less than 2 μm and 95% smaller than 5 μm. Surface area is on the order of 30,000 cm2 g-1.


Moist and warm environments, of various areas, can cause scab problems in the apple and pear trees, as these are the most common and favorable situations for the fungal disease to attack. To get rid of these stressful problems copper oxychloride Demildex can be relied upon as treatment for apple and pear scab, and has the ability to protect the fruit and foliage from infection. It is because it contains a reduced copper chloride amount in the end product, which is never going to affect the productivity level of the plants or trees. Ultimately, this can lead to effective and highly successful scab disease management.

Copper oxychloride Demildex is a scab apple treatment which will interfere with the spores and mycelium enzymes systems that are causing irreversible damage to the plants. It will also create a chemical barrier that is highly protective against fungal invasion. The smaller size of the particles can adhere to the surface of the plant significantly better as compared to industry standards and will lead to an effective increase in antibacterial and antifungal activities.

apples in a crate that were protected with copper oxychloride

Many highly effective fungicides are manufactured with the use of scrap copper, however Demildex is produced from well refined, highly pure copper. The copper oxychloride is dissolved slowly in the moisture of the plant on the leaf in the presence of a weak organic acid. As the scab plant disease takes hold to a greater extent during rainy weather, copper in a small amount will be released on the surface of the plant which can inhibit or kill microorganisms’s reproduction, it is this which acts as the prevention mechanism against scab . Demildex copper oxychloride is a superior quality fungicide that provides encouraging results that controls the problem in a short time frame and will prevent fruit and leaves from more damage in a most effective way.

Considerations For The Use Of Copper-Based Chemical Fungicides

Excess copper levels passing into the soil and eventually into other plants can lead to lower productivity levels in those plants, and as such, the application of any copper-based fungicide must be carefully calculated and controlled so as not to apply too much copper to the soil. Additionally, such calculations will reduce the likelihood of eutrophication occurring from runoff. Additionally, copper is toxic to aquatic life. A time not less than 14 days should pass before any harvesting takes place. Care should be taken to avoid human or animal ingestion and/or contact, and drift of spray mist onto other crops, fields or animals should be avoided, with extra care taken if utilising aerial spraying.


  • Scab is a disease that causes surface blemishes and discolouration on the surface of apples and pears, and is caused by the fungus Venturia inaequalis
  • Transmitted as spores by wind, the effects inaequalis will be observed from the springtime and all throughout the growing season
  • Chemical prevention of scab is achieved using a copper-based fungicide such as Demildex
  • Demildex neutralises the reproduction of the fungus and forms a chemical barrier against fungal infection


Demildex is a highly effective antimicrobial and fungicide for the prevention against scab in apples and pears - amongst a whole host of other diseases associated with fruiting plants. African Pegmatite is a leading producer and supplier of Demildex, as part of a wide selection of products designed to make agriculture more effective.

copper oxychloride demildex used to treat black spots on roses