Fungal Severity: Medium ⚠️ Contagious

Leaf Spot: How to Identify & Treat Fast

Leaf spot is a common fungal disease caused by various pathogens including Alternaria, Ascochyta, Colletotrichum, Septoria, and Venturia. It primarily affects leaves, causing discolored spots that can lead to premature leaf drop if left untreated.

Spread speed

Medium

Recovery time

21 days

🔍 Symptoms

Main Symptoms

! Circular brown, gray, black, or yellow spots on leaves
! Spots with concentric rings or dark margins
! Yellow halo surrounding spots
! Spots may be sunken or punch through the leaf creating holes
! Heavily infected leaves may brown completely and drop prematurely
! Angular or rounded spots with smooth or fringed edges

Visual Signs

Brown, gray, black, or yellow circular spots on leavesSpots with concentric rings or dark marginsYellow halo surrounding spotsSpots may be sunken or punch through the leaf creating holesHeavily infected leaves may brown completely and drop prematurelyAngular or rounded spots with smooth or fringed edgesFungal spores or spore-producing structures visible at spot centersSpots typically appear first on lower, shaded branches

Affected parts: LEAVES

❓ Possible Causes

→ Fungal pathogens (Alternaria, Septoria, Colletotrichum, Venturia)
→ Prolonged high humidity (12-24 hours)
→ Water splashing from rain or overhead irrigation
→ Poor air circulation between plants
→ Wet leaves for extended periods
→ Fungal spores overwintering on fallen leaves
→ Warm temperatures combined with high humidity

💊 Treatment

⚡

Quick Fixes

~11 days

Remove all visibly infected leaves

Dispose in sealed plastic bag

Apply copper-based fungicide following manufacturer instructions

Cover all foliage evenly

Adjust watering practices - water only in morning at base

Avoid wetting leaves

Second fungicide application

Check if infection is controlled

Final evaluation and possible third application if needed

Most cases resolved within 2 weeks

Materials needed:

Copper-based fungicideSpray bottlePruning shearsProtective gloves

🌿

Organic Treatment

~21 days

Remove all infected leaves and dispose away from plants

Wear gloves and sanitize scissors after use

Isolate affected plant from other healthy plants

Maintain minimum 3-foot distance

Prepare neem oil spray (2 tablespoons per quart of water)

Add a few drops of liquid soap as emulsifier

Apply neem oil to all leaves (top and bottom surfaces)

Apply in evening to avoid sun scorch

Improve air circulation around plant

Prune overlapping or overly dense branches

Reapply neem oil

Repeat weekly application

Third neem oil application

Check if new spots have stopped appearing

Final evaluation

If no new spots, plant is recovering

Materials needed:

Neem oilSpray bottleDisinfected pruning shearsMild liquid soapGardening gloves

🔬

Expert Treatment

~32 days

Precise diagnosis of causative pathogen

Send sample to laboratory if possible for exact identification

Surgical removal of all infected material

Cut several inches below visible signs

Application of pathogen-specific systemic fungicide

Strictly follow recommended dosage

Complementary application of contact fungicide (copper or sulfur)

Additional surface protection

Strategic pruning to improve light penetration

Increase spacing and airflow

Second systemic fungicide application

Maintain interval per label instructions

Apply biostimulant to strengthen natural defenses

Salicylic acid or seaweed-based products

Third systemic fungicide application

Evaluate treatment response

Preventive application of protective fungicide

Protect new growth

Complete evaluation and establish preventive program

Seasonal preventive applications as needed

Step by Step

1
Immediately remove all affected leaves and dispose
2
Isolate plant from other healthy plants
3
Relocate to dry location with good air circulation
4
Stop overhead watering, water only at plant base
5
Apply neem oil or appropriate fungicide
6
Prune to increase light penetration and air circulation
7
Remove infected branches several inches below visible signs
8
Monitor daily for new spots over next 2-3 weeks
9
Repeat treatment as needed every 7-14 days

🧪 Solutions

🌱 Natural Solutions

✓ Neem oil applied after removing affected parts
✓ Homemade baking soda spray (1 tablespoon) + horticultural soap (1 teaspoon) in 1 quart water
✓ Copper-based fungicides for severe cases
✓ Sulfur-based fungicides
✓ Garlic extract as natural preventive
✓ Chamomile tea sprayed on leaves
✓ Diluted milk solution (1:10) as preventive