🦠 Disease Diagnostic Tool

Disease Diagnostic Tool | The Trend Vault Blog

Three Types of Plant Diseases

Type	How It Spreads	Key Signs	Can You Cure It?
FUNGAL	Water splash, wind, tools	Spots, mold, powder, wilting	✅ Yes, with fungicides
BACTERIAL	Water, insects, wounds	Water-soaked spots, oozing, smell	⚠️ Difficult, remove infected parts
VIRAL	Insects (aphids), tools, hands	Mosaic, distortion, stunting	❌ No cure, prevent spread

Fungal Diseases (Most Common)

🟤 Powdery Mildew

Fungal

Symptoms

White powdery coating on leaves, stems
Starts as small white spots, spreads to cover leaf
Leaves may curl, yellow, drop
Common on cucurbits, roses, beans

Causes

High humidity + poor air circulation
Warm days (20-25°C) + cool nights
Crowded plants

Treatment

Method	Recipe/Application	Effectiveness
Baking Soda Spray	1 tsp baking soda + 1 tsp dish soap per 1L water. Spray weekly.	75-85%
Neem Oil	5ml neem + 2ml soap per 1L water. Spray every 7 days.	80-90%
Sulfur Fungicide	Follow package directions. Best prevention.	90-95%
Milk Spray	1 part milk + 9 parts water. Spray weekly.	70-80%

Prevention

Space plants for airflow
Water at soil level (not leaves)
Remove infected leaves immediately
Apply sulfur preventatively

🟫 Early & Late Blight

Fungal

Symptoms

Early Blight: Brown spots with concentric rings (target pattern) on lower leaves
Late Blight: Dark brown/black water-soaked patches, white mold underneath
Rapid spread, can kill plant in days
Common on tomatoes, potatoes

Treatment

Remove affected leaves immediately, bag and dispose
Apply copper fungicide (follow directions, wear protection)
Spray weekly until 2 weeks after symptoms stop
Late blight: May need to remove entire plant to save others

Products: Copper sulfate spray (₹300-500), Chlorothalonil (₹400-600)

⚫ Black Spot (Roses)

Fungal

Symptoms

Black circular spots with yellow halo
Leaves yellow and drop
Plant weakens over time

Treatment

Remove ALL infected leaves (even on ground)
Spray neem oil or fungicide every 7-10 days
Apply in spring before symptoms appear

💦 Root Rot

Fungal

Symptoms

Wilting despite wet soil
Yellow leaves
Soft, mushy, brown/black roots
Foul smell from soil

Treatment

Remove plant from pot
Cut away all brown/mushy roots with sterile scissors
Rinse remaining roots in 3% hydrogen peroxide solution
Repot in fresh, well-draining soil
Water sparingly until plant recovers

⚠️ If >50% roots affected: Plant may not survive. Try to propagate healthy cuttings.

Bacterial Diseases

💧 Bacterial Leaf Spot

Bacterial

Symptoms

Small brown/black spots with yellow halo
Spots may have water-soaked appearance
Spots grow and merge
Leaves may drop

Treatment

Remove infected leaves immediately
Apply copper-based bactericide (₹300-500)
Improve air circulation
Water at soil level only
Disinfect tools with rubbing alcohol

Prevention: Don’t work with plants when wet. Bacteria spread easily in water.

🥀 Bacterial Wilt

Bacterial

Symptoms

Sudden wilting of entire plant
Wilting doesn’t recover at night
Cut stem oozes milky/sticky sap
Common in tomatoes, cucumbers

Test

Cut stem and place in glass of water. If milky streams ooze out = bacterial wilt.

Treatment

⚠️ NO CURE. Remove and destroy entire plant immediately to prevent spread to other plants. Do not compost.

Prevention

Control cucumber beetles (they spread it)
Use resistant varieties
Rotate crops

Viral Diseases

🎨 Mosaic Virus

Viral

Symptoms

Yellow/light green mottled pattern on leaves (mosaic)
Distorted, curled, or puckered leaves
Stunted growth
Reduced fruit production
Common: Tomato, cucumber, tobacco

How It Spreads

Aphids (main vector)
Contaminated hands/tools
Infected seeds
Handling tobacco then plants (tobacco mosaic virus)

“Treatment” (No Cure)

Remove infected plant immediately, bag and trash (do NOT compost)
Control aphids aggressively
Disinfect tools with 10% bleach solution
Wash hands thoroughly before handling plants
Use resistant varieties for future planting

🌊 Leaf Curl Virus

Viral

Symptoms

Severe leaf curling
Thick, leathery leaves
Yellow veins
Stunted plant
Common in tomatoes

“Treatment”

Remove plant. Spread by whiteflies – control them to prevent re-infection.

Fungicide & Treatment Guide

Product	Type	Use For	Cost	Safety
Neem Oil	Organic	Most fungal, some bacterial	₹200-400/250ml	✅ Safe
Copper Fungicide	Inorganic	Fungal & bacterial	₹300-500/250g	⚠️ Wear protection
Sulfur Dust/Spray	Inorganic	Powdery mildew, rust	₹200-400/500g	⚠️ Don’t inhale
Baking Soda	Organic	Powdery mildew (mild)	₹40-80/kg	✅ Very safe
Chlorothalonil	Synthetic	Blights, spots	₹400-600/500ml	⚠️ Wear protection

Application Tips

Spray in early morning or evening (not midday sun)
Cover all leaf surfaces (top AND bottom)
Repeat as directed (usually every 7-14 days)
Rotate fungicides to prevent resistance
Always wear gloves when handling chemicals

Disease Prevention (Better Than Treatment!)

✅ Daily/Weekly Habits

Inspect plants daily – Catch diseases early
Remove dead/diseased material immediately
Water at soil level – Wet leaves spread disease
Water in morning – Leaves dry quickly
Disinfect tools after each use (rubbing alcohol)

✅ Setup & Planning

Space plants properly – Good airflow prevents fungal diseases
Mulch soil – Prevents soil splash (spreads diseases)
Rotate crops – Don’t plant same family in same spot yearly
Choose resistant varieties – Check seed packets
Use drip irrigation – Keeps leaves dry

✅ Soil Health

Good drainage – Prevents root rot
Don’t overwater – Most diseases love moisture
Add compost – Beneficial microbes fight disease
Check pH – Correct pH = healthier plants

When to Remove a Plant

🚫 Remove Immediately If:

Viral disease confirmed (no cure, will spread)
Bacterial wilt (wilting + oozing sap)
Severe blight covering >70% of plant
Root rot with >50% roots mushy/black

✅ Try to Save If:

Early-stage fungal disease (<30% affected)
Bacterial spot with few leaves affected
Powdery mildew (very treatable)
Root rot caught early (<30% roots affected)

Disposal

DO NOT compost diseased material
Bag in plastic and put in trash
OR burn if allowed in your area
Disinfect area where plant was growing