Why do mango leaves turn yellow?
Written by
Kiana Okafor
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Yellow leaves of mango trees indicate trouble, frequently caused by too much water, nutrient deficiency, or anthracnose fungus. My tree had yellow patches last monsoon season, so I sent in a soil sample. Results showed waterlogged tree roots and a nitrogen deficiency. I made adjustments, and it recovered in a few weeks. If you see yellow leaves, act quickly as this may affect future fruit drop.
Diagnostic Steps
- Check soil moisture with a probe meter, ideal 25-30% saturation
- Inspect leaves for black spots (anthracnose)
- Test soil pH, below 5.5 limits nutrient uptake
- Review recent fertilizer history
Treatment Protocol
- Reduce watering to 1 inch weekly if soggy
- Apply 8-3-9 NPK fertilizer at root zone
- Spray copper fungicide on dry mornings
- Prune infected leaves with sterilized shears
Water logging saturation prohibits roots from breathing air and causes leaf color to pallor. I attempted to fix the issue by amending a clay soil with four parts clay soil and one part 30% perlite. Use a good quality moisture meter for $15 that does not guess your water habits in pots or raised beds. For trees contained in pots, check for clogged holes. Every week, lift the pot to feel the density and compare. If it is light it is probably dry.
Nutrient deficiency, nitrogen specifically, first takes its toll on the older leaves of your tree. A close friend of mine recently had a tree that rebounded after applying two 8-3-9 NPK applications spaced 6 weeks apart. If the problem persists, you may use foliar sprays with fish emulsion, as they are a quick fix. Simply mix 2oz per gallon and apply at dawn so you don't burn the leaf.
Combat anthracnose through the removal of infected branches, remember to sterilize tools with rubbing alcohol between each. I spray with copper fungicide every 21 days in the rainy season. Increase spacing between trees, the increased airflow will help with fungal pressure, if a tree is infected your best line of defense is to remove infected limbs. Promptly remove fallen leaves, as they are a haven for spores.
Read the full article: How to Grow a Mango Tree from Seed in 5 Steps
