high severity

Pepper Bacterial SpotIdentification & Treatment Guide 2026

Xanthomonas euvesicatoria · Family: Xanthomonadaceae

Pepper bacterial spot (Xanthomonas euvesicatoria) causes small dark water-soaked leaf spots that turn brown with yellow halos, and raised scab-like fruit lesions. Spread by rain splash and seed. Manage with clean seed, copper + mancozeb sprays, resistant varieties, drip irrigation, and crop rotation. Copper resistance is increasing — rotate management tools.

Scan This Plant Now

Quick Diagnosis

high

Pepper Bacterial Spot

Affects: leavesstemsfruit
Peak Season: Warm wet weather (24-30°C) with frequent rain events
Spread Risk: Fast
Spread By: Rain splash, wind-driven rain, seed-borne, contaminated transplants, overhead irrigation

🔬

Glauben Sie, Ihre Pflanze hat Pepper Bacterial Spot?

Laden Sie ein Foto hoch und unsere AI diagnostiziert sie in Sekunden — mit Behandlungsempfehlungen.

Pflanze jetzt scannen

Scan this crop with our free app

Upload a photo → AI diagnosis in seconds.

Free Scan

Symptoms: What does Pepper Bacterial Spot look like?

Visual identification guide — tap each stage for details

Small dark water-soaked spots on pepper leaf from bacterial spot — Small water-soaked spots — oily appearance when backlit

Brown pepper leaf spots with yellow halos from bacterial spot — Brown spots with yellow halos causing defoliation

Raised scab-like lesions on pepper fruit from bacterial spot — Raised scab-like fruit lesions — unmarketable produce

Frühes Stadium

Small dark water-soaked spots on leaves
Tiny (1-3 mm) dark green, water-soaked, circular spots appear on lower leaves. Spots look greasy or oily when backlit.

Mittleres Stadium

Brown spots with yellow halos and defoliation
Spots enlarge to 3-5 mm, turning dark brown with yellow halos. Spots may become angular when bounded by veins. Severe infections cause extensive defoliation, exposing fruit to sunscald.

Spätes Stadium

Raised scab-like fruit lesions
Fruit develops raised, scab-like, rough-textured brown lesions (2-5 mm). Spots may crack open, allowing secondary rot organisms to enter. Severely spotted fruit is unmarketable.

Causes: Why is my plant getting Pepper Bacterial Spot?

Environmental triggers and disease cycle

Warm rain events splashing bacteria onto leaves
Contaminated seed or transplants
Overhead irrigation providing leaf wetness and splash
Working in fields when foliage is wet
Continuous pepper/tomato cropping

Disease Lifecycle

🌱

Host Plant

Susceptible crop

🦠

Pathogen

Xanthomonas

☁️

Conditions

Warm wet weather (24-30°C) with frequent rain events

🔬

Infection

Penetrates tissue

📍

Symptoms

Visible signs

💨

Spread

Rain splash

Often confused with: Tomato Bacterial Wilt, Cabbage Black Rot. See our comparison guide.

How to Treat Pepper Bacterial Spot

Tick each step as you complete it — works offline too

🌿 OrganicSafe for all farms

Organic Treatment Steps

4 steps

Apply copper hydroxide (Kocide 3000) at 1.5 g/L combined with Bacillus subtilis biocontrol for integrated protection.
Use bacteriophage-based products (AgriPhage) where available — these target Xanthomonas specifically.
Remove heavily infected lower leaves to reduce splash inoculum.
Mulch with plastic or straw to reduce rain splash from soil onto lower leaves.

🧪 ChemicalUse protective equipment

Chemical Treatment Steps

4 steps

Apply copper hydroxide + mancozeb (1.5 g/L + 2 g/L) every 7-10 days during rainy periods. Mancozeb enhances copper efficacy.
Apply acibenzolar-S-methyl (Actigard 50WG) at 0.5 g/L to induce systemic acquired resistance in the plant.
Rotate copper products with acibenzolar-S-methyl to manage copper-tolerant bacterial populations.
Start spray program at transplanting and continue through fruit development during wet weather.

Prevention & Seasonal Calendar

Year-round protection plan for your crops

Pre-Planting

Use certified pathogen-free seed or hot water treat seed (50°C for 25 minutes)
Use clean transplants from sanitary nurseries
Install drip irrigation — eliminate overhead watering

Mid-Season

Mulch to reduce soil splash onto lower foliage
Rotate with non-solanaceous crops for 2-3 years
Avoid working in fields when foliage is wet

Post-Harvest

Remove crop debris promptly after harvest

🛡️ Resistant Varieties

Varieties with Bs2 gene (resistance to most races)Plato (partial resistance)Some commercial hybrids with Bs2

View full seasonal calendar for your region →

Frequently Asked Questions

Common questions about Pepper Bacterial Spot

Why is copper resistance a problem?

Decades of copper-based spraying have selected for copper-tolerant Xanthomonas strains in many production areas worldwide. These strains carry plasmid-borne copper resistance genes (copLAB) that detoxify copper ions. Where copper-tolerant strains dominate, copper sprays provide reduced control. Adding mancozeb or using plant defense inducers (acibenzolar-S-methyl) helps compensate.

Can bacterial spot survive between seasons?

Xanthomonas survives on seed (for 10+ years), in crop debris (for several months), and on volunteer pepper/tomato plants. It does NOT survive long in bare soil without plant material. Crop rotation combined with residue destruction and clean seed effectively breaks the disease cycle between seasons.

How does bacterial spot differ from bacterial wilt?

Bacterial spot (Xanthomonas) causes leaf spots and fruit lesions but does not cause wilting. Bacterial wilt (Ralstonia) causes sudden whole-plant wilting with no leaf spots. They are caused by completely different bacteria, spread differently, and require different management approaches. Both can affect pepper, but their symptoms are distinct.

🔬

Related Disease

Tomato Bacterial Wilt

Ralstonia solanacearum

🔬

Related Disease

Cabbage Black Rot

Xanthomonas campestris pv. campestris

🌿

Affected Plant

Pepper (Capsicum)

Capsicum annuum / C. frutescens / C. chinense

💊

Treatment Guide

Full Treatment Protocol

Detailed spray schedule & dosage guide

Found this helpful?

Share with farmers in your community

Share on WhatsApp

🇩🇪Available in English

Available offline · Free forever

Diagnose Pepper Bacterial Spot right now.

Point your camera at any leaf. Get a diagnosis in seconds — even without internet. Works in the field, in the forest, anywhere.

Works offline

2-second diagnosis

8 languages

Private & free

🧑🏿

👩🏽

👨🏾

🧕🏽

New on Google Play

CuraPlant mobile app — home screen showing Scan Plant, Ask AI, My Plants, and Weather features