Avocado Anthracnose Treatment: What To Do For Anthracnose Of Avocado Fruit
By: Kristi Waterworth
Good things come to those avocado growers who wait, at least, that’s more or less how the saying goes. When it comes to harvesting and handling avocado fruit post-harvest, many avocado growers get a lot more of a surprise than they bargained for when they discover anthracnose of avocado fruit covering their bounty. What’s an avocado lover to do? Read on for more information about anthracnose on avocado trees.
Anthracnose Symptoms in Avocado
Unlike many avocado diseases that are basically cosmetic, anthracnose is often difficult to see and can selectively ruin fruits, leaving all other plant parts untouched. You might notice some leaf spots, but it’s far more likely your first brush with this fungal pathogen will occur while your fruits are ripening.
Avocados will suddenly sport small dark spots that expand rapidly, within just one or two days, as the fruit ripen. Because the skin of the immature avocado fruit is largely protective against anthracnose infection, it’s easy to have a bad case of anthracnose without even knowing it.
Although this fungus isn’t dangerous for humans to consume, it can affect fruit quality dramatically, with the damaged areas of the avocado discoloring and producing a sour flavor. Home growers can simply cut these spots out, but if you’re selling your produce, you may need to take greater steps to ensure that your avocados are marketable in the future.
Treating Anthracnose on Avocado
Avocado anthracnose treatment requires keeping several things in mind at once. First, your goal is to reduce the amount of anthracnose spores in and around your tree. This means removing all dead fruits, leaves, and branches at the end of the year and cleaning up any debris or dropped fruits that might accumulate underneath. Prune your trees so the insides are more open and allow the wind to penetrate, reducing life-giving humidity in the canopy.
Secondly, you can treat your tree as a precaution. Spraying the tree with copper fungicide every two weeks after blossom drop will ensure that your fruit is protected throughout its development. Also, treating or remedying other diseases, pests, or handling problems will also help tremendously.
Thirdly, your fruit should be carefully handled post-harvest. Cooling ripening fruits immediately and holding them at 41 degrees Fahrenheit (5 degrees C.) is vital. Temperatures of 75 degrees Fahrenheit (24 degrees C.) will accelerate the growth of any anthracnose that managed to evade your spraying efforts. Harvesting during dry conditions can help avoid contaminating fruits that were otherwise perfect.
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How to Cure Anthracnose
Sulfur and copper sprays are organic. They won’t kill anthracnose but will help to keep it under control by not allowing its spores to germinate. The Pacific dogwood tree is susceptible to a form of anthracnose. You can help to prevent this disease if you do not water them overhead. Also, keep trees pruned to allow good air circulation. In tropical climates, a type of anthracnose can affect papayas, avocados, mangoes, bananas and other fruit trees. Control is the same as described for other plants.
Treat anthracnose as soon as you notice spots on plant leaves or fruit. Your county agricultural extension office, University Extension service or Master Gardener Program can help you to identify anthracnose.
Anthracnose is a fungal disease that affects plants by forming dead areas on leaves and fruit. It can attack many different types of plants, from grasses to flowering trees such as dogwood. Found mainly in the eastern United States, the disease causes “dark, water soaked lesions on stems, leaves or fruit,” according to Planetnatural.com. It can spread quickly and cause extensive damage in less than one week after it appears. Moisture and cool temperatures are responsible for its development, so it is important to keep garden areas clean. You won’t be able to eliminate anthracnose after it enters your garden, but if you follow these simple steps you can help to reduce and control its spread.
Phytophthora fruit rot is caused by Phytophthora spp., usually P. mengei, the same fungus that causes Phytophthora trunk canker and crown rot. Phytophthora fruit rot is usually of minor importance in California. Most damage occurs after prolonged wet conditions, the same situation that favors anthracnose. In contrast to anthracnose, which is primarily a postharvest problem, Phytophthora fruit rot infections often become obvious while fruit is still hanging on the tree, as well as causing decay after harvest.
The most common cause of infection is likely the splashing of Phytophthora propagules from the soil surface to the fruit during heavy rain or sprinkler irrigation.
- Prune lower limbs so they are 2 to 3 feet from the ground.
- Maintain a thick layer of mulch to hasten decomposition of the pathogen in soil.
- Consider removing and disposing of old fruit or fruit lying on the ground because the fungus sporulates on dropped fruit.
Prune out dead limbs and twigs, and dispose chip large pieces of dead wood. Move and old fruitwood away from avocado trees.
UC IPM Pest Management Guidelines: Avocado
UC ANR Publication 3436
Avocado is a perfect addition to your home. With its oval leaves and shiny texture, it will surely complement the interior of your house.
Though this plant is known to have brown spots occasionally, dealing with it is relatively feasible if you have the right understanding and proper treatment.
If you’re Avocado is having these brown spots, check the symptoms first before applying any solutions.
Always remember that your Avocado plant requires attention and lots of patience to thrive.