Anthracnose on a berry bush

How to Treat Anthracnose in Berries, Mangos, Grapes and Avocadoes

African Pegmatite is a leading supplier of a broad array of herbicides, viruses and pesticides for the most pernicious problems in agriculture. Copper oxychloride Demildex is a highly potent treatment for the anthracnose disease affecting berries, mangoes, grapes avocados and many other crops - and is available from African Pegmatite.

 

In the early stages of the new growing season, food producers may notice some strange growth or spots on the leaves of their deciduous shrubs, crops or trees. These are the symptoms of anthracnose fungal infections.

The most common symptoms of this fungus are irregular shaped and cooured leaves with brown spots, which are especially distinctive on the underside of the leaf. This anthracnose is a fungal disease that can affect almost every type of plant, vegetable and/or fruits, ornamental plants and grains. Generally, this problem is not fatal in most cases to every plant. However, it can progress into a huge problem via secondary infections in the future if left untreated.

What is Anthracnose Disease and Which Fruit Does It Mainly Affect?

Anthracnose is a disease which occurs globally and is a common problem. It is one of the most serious and well-known diseases in horticulture. Due to its high level of damage, it normally requires both pre-harvest and post-harvest treatments. This is a problem that can affect various yields. The most commonly affected crops with anthracnose disease are mangoes, grapes, avocados and berries.

Anthracnose fungal disease goes by many names; on the twigs of avocados is also known as ‘pepper spot’, while in mangoes it is called ‘blossom blight’ and ‘degreening burn’ in citrus. Anthracnose is a general term which is being used for these diseases because all of these are affecting plants in quite a similar way and are caused by the same genus of fungi.

Anthracnose on mango plant leaf

What Does it do to Crops?

Anthracnose is basically a group of different varieties of diseases which are causing similar kinds of symptoms and problems in various plants or trees, especially in damp/humid and warm areas. Anthracnose disease can cause withering, dying, and wilting of plants in more pronounced cases. More commonly, this disease affects the developing leaves and shoots, with the most common symptoms of anthracnose fungicide including lesions of various colours (though often brown) or sunken spots in the stems, flowers, fruits or leaves of the plant. It is crucial, however, to distinguish between anthracnose and other similar leaf spot diseases. One of the simplest methods of distinguishing anthracnose is the presence of many small tan and/or brown dots on the underside of the leaf, approximately the size of a pin head.

Anthracnose is rarely fatal, and in milder cases appears only as superficial, i.e. has little to no impact on the quality of the fruit, grain or vegetable. It is true, however, that produce buyers select the best products by eye, and so the presence of spots, stains or other discolouration caused by anthracnose may result in poor take up of a producer’s crop by retailers. Some infections can also affect the branches and twigs of the trees. These can cause canker (fungal disease) on branches and twigs that result in damage of the bark, which can lead to secondary infections. However, the severity of infection normally depends on two major factors. These are the types of infected species and the causative agent. The severity of this problem can range from meager unsightliness to the death of the trees in the most extreme and highly developed cases. Secondary infections are oftentimes more seriously damaging than the anthracnose itself.

Anthracnose on grape leaves

What Causes Scab/Anthracnose?

The term anthracnose is normally used to describe the specific symptoms which are being caused by a complete genus of fungi called Colletotrichum. This is a specifically problematic species which can impact hundreds of types of plants. It can cause damage to cereal crops, grasses, vegetables, and fruits perennial crops, trees and legumes.

The fungus responsible for anthracnose across a variety of crops is from the genus Colletorichum, with species as follows:

  • Plant or plant type Anthracnose is caused by
    Tomato C. coccodes
    Cotton C. gossypii
    Cucurbits C. lagenarium
    Peppers C. capsici
    Banana C. musae
    Beans/legumes C. lindemuthianum
    Cereals C. graminicola
    Mango C. gloeosporioides
    Onion C. circinans
avacado leaf with anthracnose

Noteworthy, too, is that C. coccodes is also responsible for the similar ‘black dot’ disease in potatoes and other tubers.

The fungi that are associated with anthracnose tend to attack plants in the spring, doing so by attacking low level leaves and stems. The added moisture and elevated temperature of the spring is ideal to spread the fungal spores of genus Colletorichum which have spent their winter in the fallen twigs and leaves of the previous year’s growing season.

Anthracnose Control

The selection of proper seeding and planting materials, in addition to following planting and growing best practices are some of the most effective ways of preventing fungi of the genus Colletorichum from taking hold in the first instance. It is always important to purchase disease free seeds. It is crucial to remove any parts of the plant which appear to be infected as soon as possible.

Because of how the spores of genus Colletorichum spend winter, it is crucial to remove fallen leaves and twigs often both before and during the spring. Failure to do so will leave the door open to the spreading of the spores in the newly warm and moist climate.

bunch of grapes on the vine during sunset

Overall, it can be said that manual removal of affected fruits, leaves and shoots is the limit of non-chemical treatment of anthracnose across all plant species. Although removal of the pathogen via physical methods will result in less fungus surviving the winter and able to reproduce and infect other plants, any remaining spores may still cause damage in the next growing season. This is the case even if plants are well isolated from one another, as the fungal spores are transmitted by the wind.

Copper oxychloride Demildex, available from African Pegmatite, is the best treatment for anthracnose and scab which can protect yields for a longer period of time and in a more effective way than many other treatments. Copper oxychloride Demildex may be used to treat any plant prone to anthracnose, including, but not limited to, grape vines, mangos, avocados and apples.

What is Copper Oxychloride Demildex?

Copper oxychloride Demildex is one of the most highly effective anthracnose control options. It is a superior choice for bacterial and fungal diseases in vegetables, fruits, crops, stone fruits, ornamentals and citrus. Via its use in highly dilute treatment, it can provide better and economical control of a wide array of diseases in the crops in various situations - not just for the treatment of anthracnose affected plants. Demildex can be applied with a selection of other fertilisers or chemicals in a tank as part of a standard watering regime or pesticide treatment programme. However, be careful and avoid using any alkaline products. This can keep the plants from infection in a more effective way. It can also treat the symptoms of scab and anthracnose which you can find on the leaves, stems, flowers or fruits on the trees.

Copper oxychloride Demildex is a bactericide and fungicide which can be used to efficiently protect plants from infections such as those caused by fungi of the genus Colletorichum. Copper based fungicides have the ability to treat attacks by fungi in an effective way, in many cases without causing a loss of productivity in crops. Excess copper treatment is associated with physiological changes to plants and a commensurate loss in productivity. Demildex is applied in a very low quantity as standard.

avacadoes arranged in a peacock shape

How it is Used to Treat the Disease?

Fungal diseases such as anthracnose are more prone to attack at the beginning of the growing season - i.e. the spring - due to the enhanced moisture in the air and higher temperatures promoting the fungus’s transmission. However, to get rid of any stressed situation in a better way, it can be a better option to rely on this product which can protect the plants, fruits, and flowers from this serious disease.

farm fields

Demildex is based on a perfectly reduced amount of copper oxychloride, which will not negatively affect the yield of plants but rather it will help plants to stay protected from any of the fungal or bacterial diseases for a longer period of time with few applications. Demildex creates an effective chemical barrier which will undoubtedly protect against fungal and bacterial invasion. Most importantly, this product does not contain lead and heavy metal particles to ensure the healthy and safe condition of the plants.

With the highly labour intensive and poorly effective manual means of control, the commercial grower may prefer to protect their crops using chemical means.

Copper oxychloride Demilidex is a highly effective fungicide supplied by African Pegmatite for the control of pathogens like those of genus Colletorichum as well as other fungal species such as Venturia inaequalis, which can cause other harmful effects on similar plants.

As directed, copper oxychloride Demildex is applied to plants in an aqueous solution at up to 0.25% by volume - this equates to 2,500 ppm and an equivalent metallic copper amount of 50%. Commercial growers will find that Demildex is best applied at an early and late stage in the growing season, and again post-harvesting to maximise the prevention of fungi from surviving the winter.

Copper oxychloride is the sole active ingredient in Demilidex and the product is supplied as a fine light green powder containing the copper oxychloride active ingredient at a concentration of 850 g kg-1. Particle size is 40% smaller than 2 μm and 95% smaller than 5 μm, meaning solubility in water is not a problem. Surface area is approximately 30,000 cm2 g-1.

In terms of the mechanism of action, the way that copper ions interact with fungal cells is not fully understood. The leading theory is that copper ions interact with negatively charged portions of the cell wall on the fungi, leading to a change in shape. This change in shape modulates the membrane’s permeability, leading to an altered homeostasis component - the cell simply cannot get the nutrients it requires anymore(1). Copper oxychloride is an effective way of delivering these copper ions to the plant and fungus growing on it. Copper ions are also thought to interfere with enzymes on the spores of the fungi, causing the prevention of germination(2). Generally, the more soluble fungicides are less toxic to the surrounding soils(3).

Use Cases Of Copper Oxychloride Against Anthracnose

In real world tests against mango anthracnose, copper oxychloride was found to be effective(4) at low concentrations. For mangoes, it is also effective in the prevention of black spot diseases(5). Data also shows that the Kent cultivar of mango is more resistant than the Keitt cultivar(6). In vitro testing on coffee berry plant samples in Papua New Guinea have shown promising results for copper oxychloride, with data showing that applications across the 1 to 12 g L-1 rangesare highly effective at prevention of C. acutatum and C. gloeosporioides(7), even at the very dilute end.

In the production of olives, copper oxychloride may be used at concentrations up to 0.2 wt% and are more effective than other commercial herbicides including carbendazim, thiophanate-methyl and thiabendazole(8). Research has shown that for the treatment of anthracnose affecting avocado production, significant rains during early fruit development will have an impact on the efficacy of the fungicide(9).

Researchers have shown that copper oxychloride - applied at concentrations of up to 300 g L-1 - is a highly effective fungicide across a broad range of targets, especially grape vines, and compares favourably in performance to the traditional ‘Bordeaux mixture’ that has been used for centuries in vineyards(10). Bordeaux mixture is a combination of copper sulfate and quicklime and is applied as a preventative treatment, meaning it must be applied before any signs of fungal damage are observed. Typically requiring large quantity application, the amount of residual copper that builds up in soils is known to be a pollutant. As such, it is banned in the European Union. ‘Burgundy mixture’ is a related product which is known to have the same problems.

Soil Impact

When plants are sprayed, a proportion of the copper oxychloride solution will be taken up by the soil. While copper oxychloride is toxic to fungi, it is also toxic to organisms in/on the soil such as earthworms and snails. Even relatively dilute doses can be detrimental to earthworm reproduction(11) and snails(12). Research has shown that there is an inverse relationship between burrowing intensity of worms and soil density(13), so care should be taken to apply only the required amount of fungicide as excess amounts could lead to detriment to soil quality via reduced earthworm activity. The impact on basic soils by copper oxychloride is minimal, compared to acidic ones(14).

How it Saves Money in the Long Run by Preventing Problems and Saving Crops?

In a word, yes. Without any doubt, copper oxychloride is one of the most effective chemical solutions which is being used to treat various fungal infections in plants for a lengthy period of time. Copper based compounds have been used as the highly potent fungicides and bactericides for many decades. The use of copper oxychloride Demildex can prevent and treat the diseased areas of the plants. It will be dissolved slowly into the plant with watering and will keep the plants protected for a long period. Demildex provides a highly effective solution because of its ability to provide efficient and reliable results, without the need for continual reapplication and without the need to use it in high volumes. Demildex can help keep critical crops protected for the long run.

mango

Considerations For The Use Of Copper-Based Chemical Fungicides

Copper is a toxic material to plants in high quantities and excess copper can leach into local watercourses and potentially cause eutrophication - copper is toxic to aquatic life. As such, the use of any copper-based fungicide must be carefully considered and the quantities of the same calculated in detail. Between application and harvesting, at least 14 days must pass. As with any plant treatment, great care should be taken so as to avoid accidental ingestion and/or contact with humans or animals, with special care taken when the proposed application method is aerial spraying.

Summary

  • Anthracnose is a fungal disease that causes browning of plant leaves, wilting and potentially plant death
  • Traditional prevention methods are time consuming and are largely limited to widespread pruning and post-harvest fruit treatments
  • Copper oxychloride is a systemic, highly effective antifungal treatment that prevents the fungi responsible for anthracnose from causing harm

 

Copper oxychloride is a highly effective treatment for anthracnose disease, which can be catastrophic for certain fruiting plants. African Pegmatite is a trusted partner for agriculture, providing a wide range of herbicides and other products for optimal farming efficiencies.

copper oxychloride demildex powder in a pot

References

1          G. Borkov et al., Curr. Med. Chem., 2005, 12, 2163

2          F. D. Chester, J. Mycol., 2980, 6, 21

3          E. C. Hislop, Annal. Appl. Biol., 1966, 57, 475

4          K. Singh et al., Curr. J. Appl. Sci. Tech., 2017, 23, 1

5          A. Willis, Acta. Hotric., 2009, 820, 535

6          S. A. Oosthuyse, S. Afr. Mango Growers Yearbook, 1999, 19, 40

7          M. K. Kenny et al., Plant Prot. Qtr., 2012, 27, 2

8          R. L. Sharma and J. L. Kaul, Ind. J. Mycol. Plant Pathol., 1993, 20, 185

9          L. Coates, Production, formulation and application of biological control agents for avocado anthracnose, Queensland Department of Agriculture and Fisheries, Brisbane, 1996

10       Z. DeYong et al., J. S. Chin. Agri. U., 2009, 30, 36

11       B. Helling et al., Ecotoxicol. Env. Safety, 2000, 46, 108

12       M. S. El Sadany et al., J. Plant Protect. Pathol., 2009, 34, 5243

13       H. Eijsackers et al., Ecotoxicol. Env. Safety, 2005, 62, 99

14       E. Pose et al., Agri. and Food Chem., 2009, 57, 2843