Avocado is one of the most appealing and nutritious fruit in different cuisines. It’s a highland plant and that’s why it is a bit sensitive to different climatic and edaphic conditions.
This high-value crop mostly suffers from root problems. Avocado root browning is one of such issues which can be caused by overwatering, Phytophthora rot, improper soil conditions, root nematodes, and root breakage.
However, some management practices can easily solve these. So, if you are looking for the fixes to get rid of brown roots in avocado you are just in the right place.
Keep reading more to know how your avocado roots can be better again. At the end, you would cherish the results. So, let’s start without further ado.
5 Causes of Avocado Roots Turning Brown [Troubleshooting]
Due to the shallow root system, avocados don’t need much water to grow. Most of the time the roots are expanded at a depth of 15 centimeters only. So, you need to be careful about watering avocado plants.
Excessive watering can lead to mushy roots which will develop root rot easily. Smaller and yellower leaves are the common sign in an overwatered plant. Gradually, brown to black roots will appear in such conditions.
Sometimes wilting may appear with leaf curling if your plant is overwatered.
To avoid such problems, proper watering of your avocado plants is very much important. Keep reading to know how you can prevent your avocado roots from turning brown in water.
First of all, you need a humidity detector to keep checking the proper moisture level in the soil. You can check this one. (Our Pick: Atree Soil pH Meter, 3-in-1 Soil Tester Kits with Moisture,Light and PH Test for Garden)
You can also test the soil on your own. Dip your index finger at a depth of 2 centimeters. If you feel the moisture in this range, you may not need to water.
Even watering is needed in avocado plants. For the first few years, before establishment, watering twice or thrice every 7 days is enough. In the case of mature plants, 5 centimeters of irrigation is necessary. You don’t need to water more than this. Follow this schedule to escape the chance of overwatering.
Last but not the least, provide proper drainage to allow runoff of excess water.
2. Phytophthora Root Rot
Weak roots are prone to be attacked by this fungus. Mainly these fungi remain in the soil in a dormant condition. When the soil is waterlogged, the spores germinate and attack the damaged roots. Healthy avocado roots can also be affected if exposed for long.
Common symptoms of root rot are the browning of roots with a soggy appearance. In plants, you may notice stunted growth with small and pale yellow to greenish leaves.
At the initial stage of infection, pruning of roots helps a lot in controlling Phytophthora rot. You have to dig the base soil from the top to the level down where the main root exists. Then you can cut off the affected roots.
After such pruning, it is advised to keep the roots exposed for some time to heal the cuts by drying.
An important caution to mention here, clean your pruning equipment before and after such practice. This will reduce the risk of further infections.
Be careful about the sanitation in your yard. Do not put the infected and pruned-out materials in your compost pile.
As the disease progresses, root rot treatment in avocado becomes an important call out. You need to apply some fungicides to control disease incidents. Here is my recommendation that can be effective with proper cultural practices and field management. (Our Pick: Bonide Revitalize® Bio Fungicide Concentrate)
Streptomyces griseoviridis is a bacteria that is proven to treat phytophthora root rot if inoculated in soil properly. These are available in commercial form.
- One part of 3% hydrogen peroxide.
- Two part of water.
Steps to follow:
- Add hydrogen peroxide and water together.
- Pour this mixture into a spray bottle and spray or pour it directly into the affected root portions to treat root rots effectively.
Prevention is considered to be the most effective in controlling phytophthora root rot. Some easy precautions can save your avocado roots from turning brown. Let’s check what these can be.
First of all, choose your planting materials carefully. Search for disease-free certified rootstocks to prevent any infection. This will save you from a lot of hassles in the future.
Keep checking your roots often. Covering up exposed roots reduces the chances of surface damage. Then you must avoid overwatering. Follow the watering schedule as mentioned before.
Another effective measure is soil solarization. In this process, the soil is covered with clear polythene sheets to capture solar radiation. Fungal pathogens are killed through the trapped heat. However, this method is effective when the uppermost 5 centimeters of the top soil reaches a temperature of 40℃ to 55℃. So, you need to keep checking the temperature.
Last but not the least, try to prune off the broken or damaged roots. Broken roots are even more susceptible to pathogens. So, you need to take care of them on time.
3. Improper Soil Condition
Soil has a close relation to plant health. Improper or heavy soil can easily cause water logging conditions which promote brown roots in avocado.
In waterlogged conditions, plant roots suffer from a lack of oxygen which results in serious root damage. Besides, plants staying in water for long periods can easily develop root rot. These cause the brown root of avocado.
If you are providing all favorable conditions, still your avocados are showing root rot signs; you may need to check the soil. It’s not impossible that the soil is creating all the difficulties even after a certain growth of the plants.
So, let’s check what you can do with an inappropriate soil issue to combat brown roots in avocados.
Well-composted soil is very much needed to grow avocado. As the roots have to spread around finely, a bit loose yet rich and well-manured soil is suggested to be chosen for growing avocados.
If your soil is too hard to a certain depth, you can add garden manure at an initial stage. Before that, you may need to loosen the hard soil with spade. Then add the manure.
Organic manure is a great option when it comes to making soils fluffier. Citrus manure is often used in avocado plants to recover soil issues. For the first year of growth, you can put this in your soil once in every 60 days. In pot grown avocados, plants are directly grown in such manure to retain proper soil conditions.
Adding a certain amount of sand to heavy clay soil will loosen them up a bit and also will allow better drainage. These will discard the chances of water stagnant conditions in your plant base.
Soil pH is also a sensitive criterion for growing avocados. pH ranging from 5 to 7 is favorable in most cases. High alkaline soils damage plant roots which can cause brown roots.
So, you need to keep checking the soil pH constantly. A pH meter can help you in this. You can check this one. (Our Pick: Atree Soil pH Meter, 3-in-1 Soil Tester Kits with Moisture,Light and PH Test for Garden)
To reclaim alkaline soil you can add sphagnum peat, elemental sulfur, aluminum, iron sulfate, and organic mulches. 180 kg to 220 kg per 10 square meters is the most suggested dose.
Did you know that you can manipulate soil texture with some easily available ingredients? These are great in an emergency. Check this one out.
- Grass cuttings
- Leaf molds
- Shredded newspapers
Steps to follow
- Add water to newspaper cuttings and grasses.
- Keep them overnight.
- Incorporate this with leaf molds and add this to the surrounding soil.
Caution – Avoid using diseased plant parts in preparing such a mixture.
Nematodes can also cause serious damage to the plant roots. The Meloidogyne genus is the most common in such cases.
If you notice root nodules in your avocados, nematodes can be the reason. Even root lesions are also formed in brown to black color due to the attack. The upper plant parts may also show symptoms like wilting, yellowing of leaves, plant stunting, and a gradual decline in avocado yield.
To control nematodes and reduce further root browning and damage, you can take a look at what I got for you. Keep going through the suggestions.
The primary control is tilling up the soil. This will expose the nematodes to the sun and these will be killed by sun drying. You may need to repeat this process twice or thrice for desired results.
This process is closely related to soil solarization. In the case of pot planted avocadoes, you can put the soil in the oven at a temperature of 60°C for 15 to 20 minutes. This will reduce the nematode population.
In garden soil, the same process can be done by covering up the soil with plastic sheets on hot summer days to trap heat to kill nematodes. It may take almost a week to see good results. So, have a bit of patience.
If all the cultural methods fail in controlling nematodes, you may need to simply go for a nematicide. You can use this one specially formulated for fruits. (Our Pick: Growers Trust Nematode Control Non-Toxic, Biodegradable – Natural Nematode)
5. Root Breakage
Avocados grow well in well-drained soil where their aggressive roots can easily spread to look for water and nutrients. Due to such competition, roots can break down with growth. If there is some kind of infrastructure near your avocado plants, the chances of surface damage increase.
Broken roots are very much susceptible to any kind of pathogen attack. As you already know these pathogens are the main culprit behind brown roots in avocado, so it’s important to take care of such issues as soon as possible.
To reduce root damage due to breakage, the best measure is to plant your avocado plants away from any buildings and boundary walls. This will allow the roots to distribute properly.
You may need to cut the broken roots. Use sterilized scissors for such purposes. Then you have to apply some bleach solution to eliminate the chances of any pathogen attack.
Plant sealers are very much popular now. You can use them in any kind of root damage caused by physical injury.
Question- Why are my avocado roots turning brown?
Answer- The most common reason can be root rot. Most of the time rot causes initial brown spots which are later developed into black to brown mushy rots.
Other possible reasons that influence such browning are unsuitable soil conditions and nematode and pathogen attacks. All of the treatments to combat such issues are mentioned above, so you don’t need to worry about these much.
Question- How do you know if an avocado plant has root rot?
Answer- Avocado root rots can be detected by some upper portion symptoms. Plant parts like leaves, twigs, and fruits show such signs which will tell you that you might dig down to the roots and check whether they are rotting or not.
The most common symptoms are pale green to yellow leaves, wilting, smaller foliage development, and reduction in fruit size and yield. So, if these are prominent, start treating your plant roots quickly.
Question- How do you fix root rot in avocado?
Answer- Proper watering and drainage can save your plant in most of the cases. Besides these, look for treating any sort of pathogen attacks as they appear.
Potassium phosphate containing fungicides are very much effective in withstanding root rots in avocados. The one I have mentioned in the previous case will work the same as well. So, don’t hesitate to use such chemicals in severe rots.
In this article, I have tried my best to help you in dealing with avocado root browning. It needs a bit of patience and some effort to combat such issues. As I have already discussed the fixes, it won’t be that hard for you.
Just provide proper irrigation and drainage, treat pathogen attacks as mentioned, and keep monitoring your plants. You can ask for any information or queries related to avocados in the comment section. So keep working on it and stay connected.
- What to Plant With Indian Hawthorn? – 9 Exclusive Plant Ideas - May 28, 2023
- 3 Reasons For Hawthorn Leaves Turning Black – [Remedy Guide] - May 24, 2023
- 5 Causes Why Brunnera Jack Frost Leaves Turning Brown? - May 23, 2023