Brown leaves on a mango tree signal an underlying health issue. Understanding the browning pattern helps pinpoint the cause, which can range from environmental stressors to biological agents.
Identifying the Type of Browning
How mango leaves brown offers clues for diagnosis. Browning at leaf tips may indicate water or salt issues. Brown edges or margins can point to nutrient imbalances or environmental stress. Distinct spots or patches suggest disease or localized damage.
An entire brown leaf could signal severe problems like root rot or cold damage. Note if new or older leaves are affected to narrow causes. Browning on one side might suggest excessive sun exposure or wind damage.
Watering Problems
Both too little and too much water cause mango leaves to brown, with distinct symptoms. Underwatering makes leaves crispy, dry, and shriveled, starting at tips and edges, due to insufficient moisture. Establish a consistent, deep watering schedule and check soil moisture before irrigating.
Overwatering leads to root rot, depriving roots of oxygen and causing decay. Symptoms include yellowing leaves turning brown and general wilting despite wet soil. The soil might also develop a foul odor. Improve drainage by allowing soil to dry completely between waterings or, in severe cases, repotting into a well-draining mix.
Nutrient Deficiencies and Soil Issues
Imbalances in soil nutrients or pH, and salt accumulation, cause mango leaves to brown. Excess salts from fertilizers or irrigation water build up, leading to tipburn (browning at leaf tips and edges). Flush the soil with plain water to remove accumulated salts, and use rainwater or distilled water for irrigation to prevent future buildup.
Specific nutrient deficiencies cause browning. A lack of magnesium can contribute to tipburn. Deficiencies in micronutrients (zinc, potassium, calcium) can lead to browning. Soil testing identifies precise deficiencies, allowing targeted fertilization to correct imbalances and ensure proper nutrient uptake, which is influenced by soil pH.
Environmental Stress and Damage
Environmental factors can stress mango trees, causing leaves to brown. Sunburn or heat stress results in scorched or bleached patches, especially on leaves exposed to intense sunlight or reflected heat. Provide temporary shade during peak sun hours or plant the tree in a location with afternoon protection to mitigate damage.
Cold damage, especially frost, can blacken and shrivel leaves. Protect young trees with covers or blankets when temperatures drop to prevent harm. Strong winds can desiccate leaves, causing windburn where leaves dry and brown. Low humidity can crisp leaf tips, and reflected heat or compacted soil also stress the tree.
Diseases and Pests
Fungal and bacterial diseases, and certain pests, commonly cause browning mango leaves. Anthracnose, a fungal disease, presents as irregular black or brown spots that expand and merge, leading to blighted areas and leaf browning. Management includes fungicides, pruning infected branches for air circulation, and removing fallen debris.
Other diseases like brown spot (Fusarium species) manifest as small, dark brown spots merging into larger necrotic areas. Powdery mildew causes whitish growth on leaves, leading to discoloration and browning. Pests like thrips, mites, or aphids feed on sap or damage leaf tissue, resulting in discoloration, stippling, browning, or leaf drop. Identifying the specific pest or disease is essential for treatment, which may involve insecticidal soaps, neem oil, or targeted fungicides.
Preventative Care and Long-Term Health
Maintaining a consistent watering schedule prevents leaf browning. Deep watering encourages robust root development, helping the tree absorb nutrients efficiently.
Apply balanced fertilizer based on soil test results to ensure necessary nutrients without toxic buildups. Plant in well-draining soil to prevent waterlogging and root issues. Regular pruning of dead or diseased branches improves air circulation, reducing fungal risk. Monitor for early signs of pests or diseases for prompt intervention. A planting location with adequate sunlight and protection from extreme conditions contributes to long-term health.