Algal leaf spot
Fuzzy round green to orange spots on the upper side of the leaves, and black rough spots on guava fruit.
Crops it strikes
What you see
When to act
In the wet season, check low and shaded branches. Act when the fuzzy orange spots spread over many leaves or show on guava fruit. A few spots on old leaves need no action.
What to spray
Active ingredients only, never brands. The FRAC group tells how it works: switch to a different group next time, so the disease does not learn to survive it. Spray only when the damage is worth the cost, and only with products registered with the Fertilizer and Pesticide Authority for your crop. Follow the label. The Shopee and Lazada links only show who sells something with that active ingredient, not a recommendation of any seller or product.
Spraying is seldom worth it. Prune low branches, open the canopy to light and air, drain wet ground and feed the trees well.
How to prevent it
- Prune low hanging branches and thin the canopy so light and air reach the inner leaves.
- Drain waterlogged ground and keep weeds down around the trees to lower the damp.
- Feed weak trees. The alga hits poorly growing trees hardest.
- Thin shade trees that keep cacao and coffee too dark and wet.
- In wet areas, space guava trees wide, with rows that let the wind pass.
Where this comes from
Not sure it is this one?
Many diseases look alike. Send a photo to Anee, the smart farm technician in anee.io. She reads it with your crop, its age and the weather, and tells you what it most likely is and what to do first. In Tagalog or English.