While avocado trees are cherished for their lush foliage and delicious fruits, they can be challenging to maintain due to their sensitivity to minerals, salinity, and fertilizers. Moreover, susceptibility to various root rot types adds to the potential problems. If you notice signs of infection or distress in your avocado tree, prompt action is crucial. Here’s a guide to addressing common symptoms based on the specific issues your tree may be facing.
Drooping Leaves and Leaf Loss
- Water the tree when the soil is completely dry, avoiding a fixed watering schedule.
- If drooping persists despite proper watering, investigate potential root damage.
How to Fertilize an Avocado Tree
- Avoid watering with salt or hard water to prevent root burns.
- Refrain from fertilizing a recently transplanted tree; wait until it’s established.
- Use a fertilizer with extra nitrogen and zinc, such as a 16-4-8, for established and healthy trees.
Brown Leaves and Branches Turning Black
Identification:
- Rosellina root rot: White patches on trunk or limbs, purple growths near the soil.
- Oak root rot: Clusters of small yellow or brown mushrooms near the soil line.
- Common avocado root rot: Brown leaf tips, black/rotting feeder roots, potentially dead branches.
Action:
- Rosellina root rot: Considered fatal; replace the tree and infected soil.
- Oak and Common root rot: Apply Agri-fos fungicide immediately and biannually for prevention. Incorporate gypsum into the soil to inhibit spread.
- For severe infections, expose roots to sunlight by carefully removing the topsoil, allowing them to dry, and replacing it with new, uninfected soil.
Sunburn
- Protect sensitive bark by painting the trunk and larger limbs white.
- Dilute white latex paint with equal parts water and apply generously.
- Alternatively, use Fosetyl-Al (Aliette®) fungicide as trunk paint.
After implementing these treatments, closely monitor your avocado tree for signs of recovery. With proper care, you can expect it to regain its upright stance and display healthy new growth.
