This presentation covers the major insect pests of tomato, focusing on their identification, biology, nature of damage, and management strategies. Emphasis is placed on integrated pest management, including biological, cultural, and chemical control methods. Understanding these pests is essential for sustainable tomato production and minimizing crop losses. Key academic terms include Helicoverpa armigera, Tuta absoluta, integrated pest management, vector, and biological control.
Introduction to Tomato Pests
- Tomato is affected by several major insect pests worldwide.
- Pests cause direct damage and act as vectors for viral diseases.
- Effective management is crucial for yield and quality.
Tomato Fruit Borer (Helicoverpa armigera)
Scientific Name: Helicoverpa armigera
Family: Noctuidae
Order: Lepidoptera
Distribution: Tropics, subtropics, and warmer temperate regions
Economic Importance:
- Major pest of tomato and other crops (e.g., pigeon pea, chickpea).
Tomato Fruit Borer – Identification and Life Cycle
Identification:
- Caterpillar: Varies in color, radiating hairs, brown to greenish with dark lines.
- Moth: Medium-sized, light yellowish-brown, forewings with dark spot, hindwings pale with black border.
Life Cycle:
- Eggs laid on tender plant parts.
- Larval stage: 18–25 days.
- Pupates in soil.
- Total life cycle: 30–40 days.
Tomato Fruit Borer – Nature of Damage
- Young larvae feed on foliage; older larvae bore into fruits.
- Creates circular holes in fruits, feeds on inner contents.
- Damaged fruits often infected by secondary pathogens.
- One larva can destroy 2–8 fruits.
Tomato Fruit Borer – Management
Cultural Control:
- Collect and destroy infested fruits and larvae.
- Deep ploughing after harvest to expose pupae.
- Intercrop tomato with marigold (1:16 rows).
Biological Control:
- Release Trichogramma spp. and Chrysoperla carnea.
- Spray Bacillus thuringiensis (2g/lit).
- Use Helicoverpa NPV (HaNPV) @ 250 LE/ha.
Chemical Control:
- Use pheromone traps (Helilure) @ 12/ha.
- Spray recommended insecticides: Azadirachtin, Indoxacarb, Flubendiamide, Novaluron, Phosalone, Quinalphos.
Serpentine Leaf Miner (Liriomyza trifolii)
Scientific Name: Liriomyza trifolii
Family: Agromyzidae
Order: Diptera
Identification:
- Larva: Minute, orange-yellow, apodous maggots.
- Adult: Small, pale yellow flies.
Life Cycle:
- Eggs laid singly on upper leaf surface.
- Larval period: 7–10 days; pupates in soil or leaves.
- Total life cycle: ~3 weeks.
Serpentine Leaf Miner – Damage and Management
Nature of Damage:
- Larvae mine between leaf epidermal layers, creating serpentine trails.
- Severe infestation causes leaf drying and drop.
Management:
- Collect and destroy mined leaves.
- Spray neem seed kernel extract (NSKE) 5%.
Tomato Leaf Miner (Tuta absoluta)
Scientific Name: Tuta absoluta
Family: Gelechiidae
Order: Lepidoptera
Nature of Damage:
- Larvae mine leaves, stems, and fruits.
- Causes leaf necrosis, fruit damage, and yield loss.
Management:
- Use pheromone traps, biological control agents, and selective insecticides.
Whitefly (Bemisia tabaci)
Scientific Name: Bemisia tabaci
Family: Aleyrodidae
Order: Hemiptera
Identification:
- Eggs: Pear-shaped, light yellow.
- Nymphs: Oval, scale-like, greenish-white.
- Adults: Tiny, white, scale-like.
Whitefly – Damage and Management
Nature of Damage:
- Nymphs and adults suck sap, causing chlorosis and leaf curling.
- Vector of tomato leaf curl virus.
Management:
- Uproot and destroy infected plants.
- Remove alternate weed hosts (e.g., Abutilon indicum).
- Use yellow sticky traps (12/ha).
- Apply carbofuran or recommended insecticides: Dimethoate, Malathion, Oxydemeton-methyl, Thiamethoxam.
Aphids (Aphis gossypii, Myzus persicae)
Scientific Names: Aphis gossypii, Myzus persicae
Family: Aphididae
Order: Hemiptera
Nature of Damage:
- Nymphs and adults suck sap, causing yellowing and deformation.
- Honeydew secretion leads to sooty mould, reducing photosynthesis.
Management:
- Seed treatment with imidacloprid or thiamethoxam.
- Use yellow sticky traps.
Thrips (Thrips tabaci)
Scientific Name: Thrips tabaci
Family: Thripidae
Order: Thysanoptera
Identification:
- Nymphs: Yellowish.
- Adults: Dark, fringed wings.
Nature of Damage:
- Silvery streaks on leaves, bud necrosis, flower drop.
- Vector of tomato spotted wilt virus.
Thrips – Management
- Uproot and destroy diseased plants.
- Use yellow sticky traps (15/ha).
- Release Chrysoperla carnea larvae (10,000/ha).
- Spray methyl demeton 25 EC or dimethoate 30 EC @ 1 L/ha.
Red Spider Mite (Tetranychus spp.)
Scientific Name: Tetranychus spp.
Family: Tetranychidae
Order: Acarina
Identification:
- Eggs: Hyaline, globular, laid in masses.
- Nymphs: Yellowish.
- Adults: Small, red.
Nature of Damage:
- Leaves turn reddish-brown, bronzed, and dry.
- Webbing on leaves; reduced flower and fruit formation.
Red Spider Mite – Management
- Spray wettable sulphur 50 WP @ 2g/lit.
- Spray dicofol 18.5 EC @ 2.5 ml/lit.
Summary: Integrated Pest Management in Tomato
- Combine cultural, biological, and chemical methods for effective pest control.
- Monitor pest populations regularly.
- Use resistant varieties and crop rotation.
- Minimize pesticide use to prevent resistance and protect beneficial organisms.
Objective Questions
Q1. Which family does the tomato fruit borer, Helicoverpa armigera, belong to?
A. Noctuidae
B. Gelechidae
C. Agromyzidae
D. Aleurodidae
Answer: A
Q2. What is the recommended ratio of American tall marigold to tomato seedlings for managing tomato fruit borer?
A. 1:10
B. 1:16
C. 1:20
D. 1:25
Answer: B
Q3. Which insecticide is recommended at a dose of 8 ml/10 lit for tomato fruit borer control?
A. Flubendiamide 20 WG
B. Indoxacarb 14.5% SC
C. Novaluron 10% EC
D. Quinalphos 25% EC
Answer: B
Q4. Which pest is a vector of tomato leaf curl disease?
A. Thrips tabaci
B. Bemisia tabaci
C. Aphis gossypii
D. Tuta absoluta
Answer: B
Q5. What is the order of the serpentine leaf miner, Liriomyza trifolii?
A. Lepidoptera
B. Hemiptera
C. Diptera
D. Thysonoptera
Answer: C
Q6. Which biological control agent is released at 1 lakh/ha for tomato fruit borer management?
A. Trichogramma chilonis
B. Trichogramma pretiosum
C. Chrysoperla carnea
D. Bacillus thuringiensis
Answer: B
Q7. Which chemical is applied at 2g/lit for red spider mite management?
A. Dicofol 18.5 EC
B. Wettable sulphur 50 WP
C. Carbofuran 3% G
D. NSKE 5%
Answer: B
Q8. Which pest causes silvery streaks on tomato leaves and is a vector of tomato spotted wilt virus?
A. Aphis gossypii
B. Thrips tabaci
C. Tetranychus spp
D. Liriomyza trifolii
Answer: B
Q9. Which of the following is NOT a recommended insecticide for whitefly control on tomato?
A. Dimethoate 30% EC
B. Malathion 50% EC
C. Thiamethoxam 25% WG
D. Flubendiamide 20 WG
Answer: D
Q10. What is the color of the adult red spider mite?
A. Yellow
B. Green
C. Red
D. Brown
Answer: C
This presentation provides an overview of major insect pests affecting tomato crops, focusing on their identification, nature of damage, life cycle, and management strategies. Emphasis is placed on integrated pest management, including biological, cultural, and chemical control methods. Key pests discussed include the tomato fruit borer, serpentine leaf miner, whitefly, aphids, thrips, and red spider mite. The content is essential for understanding pest dynamics, crop protection, and sustainable tomato production. Important academic keywords include pest identification, life cycle, damage symptoms, integrated pest management, and chemical control.
Introduction to Tomato Pests
- Tomato is susceptible to several insect pests causing significant yield loss.
- Pests affect all growth stages: seedling, vegetative, flowering, and fruiting.
- Effective management requires correct identification and integrated approaches.
Tomato Fruit Borer (Helicoverpa armigera)
Family: Noctuidae
Order: Lepidoptera
Distribution: Tropics, subtropics, and warmer temperate regions.
Identification:
- Caterpillars: Varying colors, radiating hairs, brown to greenish with dark lines.
- Moth: Stout, light yellowish-brown, forewings with dark spot, hindwings smoky white.
Tomato Fruit Borer – Life Cycle and Damage
Life Cycle:
- Eggs laid on tender plant parts.
- Larval stage: 18–25 days, pupates in soil.
- Total life cycle: 30–40 days.
Nature of Damage:
- Young larvae feed on foliage; older larvae bore into fruits.
- Circular holes in fruits; internal feeding causes rotting.
- One larva can damage multiple fruits.
Tomato Fruit Borer – Management
- Collect and destroy infested fruits and larvae.
- Intercrop with marigold (1:16 rows) to attract egg-laying adults.
- Deep ploughing after harvest exposes pupae to predators.
- Install pheromone traps (Helilure) at 12/ha.
- Use resistant varieties: Rupali, Roma, Pusa Red Plume.
- Spray Bacillus thuringiensis (2g/lit).
- Release Trichogramma pretiosum or T. chilonis for egg parasitism.
- Spray HaNPV @ 250 LE/ha for larval control.
- Release Chrysoperla carnea larvae for biological control.
Chemical Control:
- Azadirachtin 1% EC: 2 ml/lit
- Indoxacarb 14.5% SC: 8 ml/10 lit
- Flubendiamide 20 WG: 5 g/10 lit
- Novaluron 10% EC: 7.5 ml/10 lit
- Phosalone 35% EC: 13 ml/10 lit
- Quinalphos 25% EC: 1 ml/lit
Serpentine Leaf Miner (Liriomyza trifolii)
Family: Agromyzidae
Order: Diptera
Identification:
- Larva: Minute, orange-yellow, apodous maggots.
- Pupa: Yellowish-brown, found in soil or leaves.
- Adult: Pale yellow, small fly.
Life Cycle:
- Eggs laid singly on upper leaf surface.
- Larval period: 7–10 days; total cycle ~3 weeks.
Nature of Damage:
- Maggots mine between leaf epidermal layers.
- Serpentine mines visible; severe cases cause leaf drying and drop.
Management:
- Collect and destroy mined leaves.
- Spray neem seed kernel extract (NSKE) 5%.
Tomato Leaf Miner (Tuta absoluta)
Family: Gelechiidae
Order: Lepidoptera
Identification:
- Small greyish-brown moth; larvae mine leaves, stems, and fruits.
Nature of Damage:
- Leaf mining, fruit boring, and stem tunneling.
- Leads to leaf necrosis, fruit rot, and yield loss.
Management:
- Use pheromone traps for monitoring and mass trapping.
- Remove and destroy infested plant parts.
- Apply Bacillus thuringiensis or recommended insecticides.
Whitefly (Bemisia tabaci)
Family: Aleyrodidae
Order: Hemiptera
Identification:
- Eggs: Pear-shaped, light yellow.
- Nymphs: Oval, scale-like, greenish-white.
- Adults: Tiny, white, scale-like.
Nature of Damage:
- Nymphs and adults suck sap, causing chlorosis and leaf curling.
- Vector of tomato leaf curl virus.
Management:
- Uproot and destroy diseased plants.
- Remove alternate weed hosts (e.g., Abutilon indicum).
- Install yellow sticky traps (12/ha).
- Apply carbofuran 3% G @ 40 kg/ha or recommended insecticides.
Chemical Control:
- Dimethoate 30% EC: 1 ml/lit
- Malathion 50% EC: 1.5 ml/lit
- Oxydemeton-methyl 25% EC: 1 ml/lit
- Thiamethoxam 25% WG: 4 ml/10 lit
Aphids (Aphis gossypii, Myzus persicae)
Family: Aphididae
Order: Hemiptera
Nature of Damage:
- Nymphs and adults suck sap from leaves and stems.
- Infested plants become yellow, deformed, and may dry up.
- Honeydew secretion leads to sooty mould, reducing photosynthesis.
Management:
- Seed treatment with imidacloprid or thiamethoxam.
- Use yellow sticky traps.
Thrips (Thrips tabaci)
Family: Thripidae
Order: Thysanoptera
Identification:
- Nymphs: Yellowish.
- Adults: Dark, fringed wings.
Nature of Damage:
- Silvery streaks on leaves, flower drop, bud necrosis.
- Vector of tomato spotted wilt virus.
Management:
- Uproot and destroy diseased plants.
- Install yellow sticky traps (15/ha).
- Release Chrysoperla carnea larvae (10,000/ha).
- Spray methyl demeton 25 EC or dimethoate 30 EC @ 1 lit/ha.
Red Spider Mite (Tetranychus spp.)
Family: Tetranychidae
Order: Acarina
Identification:
- Eggs: Hyaline, globular, laid in masses.
- Nymphs: Yellowish.
- Adults: Small, red.
Nature of Damage:
- Leaves turn reddish-brown, bronzed, and dry.
- Webbing on leaves; severe cases affect flowering and fruiting.
Management:
- Spray wettable sulphur 50 WP (2g/lit).
- Spray dicofol 18.5 EC (2.5 ml/lit).
Summary: Integrated Pest Management in Tomato
- Accurate pest identification is crucial for effective management.
- Combine cultural, biological, and chemical methods for sustainable control.
- Monitor pest populations using traps and field scouting.
- Use resistant varieties and timely interventions to minimize losses.
Objective Questions
Q1. Which family does the Tomato Fruit Borer, Helicoverpa armigera, belong to?
A. Noctuidae
B. Gelechidae
C. Agromyzidae
D. Aleurodidae
Answer: A
Q2. What is the recommended ratio of American tall marigold to tomato seedlings for managing Tomato Fruit Borer?
A. 1:10
B. 1:16
C. 1:20
D. 1:25
Answer: B
Q3. Which insecticide and dose is recommended for controlling Tomato Fruit Borer using Flubendiamide?
A. 8 ml/10 lit
B. 5 g/10 lit
C. 7.5 ml/10 lit
D. 13 ml/10 lit
Answer: B
Q4. Which pest is identified by minute orange yellowish apodous maggots as larvae?
A. Helicoverpa armigera
B. Liriomyza trifolii
C. Tuta absoluta
D. Bemisia tabaci
Answer: B
Q5. Which pest acts as a vector for tomato leaf curl disease?
A. Aphis gossypii
B. Thrips tabaci
C. Bemisia tabaci
D. Tetranychus spp
Answer: C
Q6. Which control measure is specifically recommended for Thrips tabaci management?
A. Spray wettable sulphur 50 WP
B. Use yellow sticky traps @ 15/ha
C. Spray Bacillus thuringiensis
D. Release Trichogramma pretiosum
Answer: B
Q7. What is the recommended dose of Dimethoate 30% EC for whitefly control?
A. 1.0 ml/lit
B. 1.5 ml/lit
C. 4.0 ml/10 lit
D. 2.0 ml/lit
Answer: A
Q8. Which pest is managed by spraying wettable sulphur 50 WP at 2g/lit?
A. Tuta absoluta
B. Thrips tabaci
C. Tetranychus spp
D. Liriomyza trifolii
Answer: C
Q9. Which natural enemy is recommended for release at 50,000 eggs/ha from 30 days after planting for Tomato Fruit Borer management?
A. Trichogramma pretiosum
B. Trichogramma chilonis
C. Chrysoperla carnea
D. Bacillus thuringiensis
Answer: C
Q10. Which pest's nymphs and adults secrete honeydew that leads to sooty mould growth on tomato plants?
A. Bemisia tabaci
B. Aphis gossypii
C. Tetranychus spp
D. Thrips tabaci
Answer: B
This presentation covers the major insect pests of tomato, focusing on their identification, biology, nature of damage, and management strategies. Emphasis is placed on the economic impact, life cycles, and integrated pest management (IPM) approaches. Key pests discussed include the tomato fruit borer, serpentine leaf miner, whitefly, aphids, thrips, and red spider mite. The content is essential for understanding pest dynamics, crop protection, and sustainable tomato production. Important academic keywords include Helicoverpa armigera, integrated pest management, vector, life cycle, and economic importance.
Introduction to Tomato Pests
- Tomato is affected by several insect pests causing significant yield losses.
- Pests damage leaves, stems, flowers, and fruits, reducing quality and market value.
- Effective management requires knowledge of pest identification, biology, and control methods.
- Integrated pest management (IPM) is recommended for sustainable control.
Tomato Fruit Borer (<em>Helicoverpa armigera</em>)
Pathogen: Helicoverpa armigera (Family: Noctuidae, Order: Lepidoptera)
Economic Importance:
- Major pest of tomato; also attacks tur, gram, and other crops.
- Widely distributed in tropical and subtropical regions.
Identification:
- Caterpillar: Varying color, radiating hairs, brown to greenish with dark lines.
- Moth: Stout, light yellowish-brown, forewings with dark spot, hindwings smoky white with black border.
Life Cycle:
- Eggs laid on tender plant parts.
- Larval period: 18–25 days; pupates in soil.
- Total life cycle: ~30–40 days.
Nature of Damage:
- Larvae bore circular holes in fruits, feed on inner contents.
- Secondary infection by fungi and bacteria common.
- One larva can damage multiple fruits.
Tomato Fruit Borer – Management
- Collect and destroy infested fruits and larvae.
- Intercrop tomato with marigold (1:16 rows) to attract and trap adults.
- Plough fields post-harvest to expose and destroy pupae.
- Install pheromone traps (Helilure) at 12/ha.
- Grow resistant varieties (e.g., Rupali, Roma, Pusa Red Plume).
- Spray Bacillus thuringiensis 2g/litre.
- Release Trichogramma pretiosum or T. chilonis for egg parasitism.
- Spray HaNPV @ 250 LE/ha for biological control.
- Release Chrysoperla carnea larvae for predator control.
Chemical Control:
- Azadirachtin 1% EC: 2 ml/litre
- Indoxacarb 14.5% SC: 8 ml/10 litres
- Flubendiamide 20 WG: 5 g/10 litres
- Novaluron 10% EC: 7.5 ml/10 litres
- Phosalone 35% EC: 13 ml/10 litres
- Quinalphos 25% EC: 1 ml/litre
Serpentine Leaf Miner (<em>Liriomyza trifolii</em>)
Pathogen: Liriomyza trifolii (Family: Agromyzidae, Order: Diptera)
Identification:
- Larva: Minute, orange-yellow, legless maggots.
- Pupa: Yellowish-brown, found in soil or leaves.
- Adult: Small, pale yellow flies.
Life Cycle:
- Eggs laid singly on upper leaf surface.
- Larval period: 7–10 days; pupates in soil or leaves.
- Total life cycle: ~3 weeks.
Nature of Damage:
- Maggots mine between leaf epidermal layers, creating serpentine trails.
- Severe infestation causes leaf drying and drop.
Management:
- Collect and destroy mined leaves.
- Spray neem seed kernel extract (NSKE) 5%.
Tomato Leaf Miner (<em>Tuta absoluta</em>)
Pathogen: Tuta absoluta (Family: Gelechiidae, Order: Lepidoptera)
Identification:
- Small grey-brown moth; larvae are cream to greenish with dark head.
Nature of Damage:
- Larvae mine leaves, stems, and fruits, causing blotches and galleries.
- Fruit damage leads to secondary infections and yield loss.
Management:
- Use pheromone traps for monitoring and mass trapping.
- Remove and destroy infested plant parts.
- Apply biologicals (e.g., Bacillus thuringiensis).
- Use selective insecticides as per recommendations.
Whitefly (<em>Bemisia tabaci</em>)
Pathogen: Bemisia tabaci (Family: Aleyrodidae, Order: Hemiptera)
Identification:
- Eggs: Pear-shaped, light yellow.
- Nymphs: Oval, scale-like, greenish-white.
- Adults: Tiny, white, scale-like insects.
Nature of Damage:
- Nymphs and adults suck sap, causing chlorosis and leaf curling.
- Vector of tomato leaf curl virus.
Management:
- Uproot and destroy diseased plants.
- Remove alternate weed hosts (e.g., Abutilon indicum).
- Use yellow sticky traps (12/ha).
- Apply carbofuran 3% G @ 40 kg/ha or recommended insecticides.
Chemical Control:
- Dimethoate 30% EC: 1 ml/litre
- Malathion 50% EC: 1.5 ml/litre
- Oxydemeton-methyl 25% EC: 1 ml/litre
- Thiamethoxam 25% WG: 4 ml/10 litres
Aphids (<em>Aphis gossypii</em>, <em>Myzus persicae</em>)
Pathogen: Aphis gossypii, Myzus persicae (Family: Aphididae, Order: Hemiptera)
Nature of Damage:
- Nymphs and adults suck sap from leaves and stems.
- Plants turn yellow, become deformed, and may dry up.
- Honeydew secretion promotes sooty mould, reducing photosynthesis.
Management:
- Seed treatment with imidacloprid or thiamethoxam.
- Use yellow sticky traps.
- Spray recommended systemic insecticides if needed.
Thrips (<em>Thrips tabaci</em>)
Pathogen: Thrips tabaci (Family: Thripidae, Order: Thysanoptera)
Identification:
- Nymphs: Yellowish.
- Adults: Dark with fringed wings.
Nature of Damage:
- Silvery streaks on leaves, premature flower drop, bud necrosis.
- Vector of tomato spotted wilt virus.
Management:
- Uproot and destroy diseased plants.
- Use yellow sticky traps (15/ha).
- Release Chrysoperla carnea larvae (10,000/ha).
- Spray methyl demeton 25 EC or dimethoate 30 EC @ 1 litre/ha.
Red Spider Mite (<em>Tetranychus</em> spp.)
Pathogen: Tetranychus spp. (Family: Tetranychidae, Order: Acarina)
Identification:
- Eggs: Hyaline, globular, laid in masses.
- Nymphs: Yellowish.
- Adults: Small, red.
Nature of Damage:
- Leaves become reddish-brown, bronzed, and dry.
- Webbing on leaves; severe infestations reduce flower and fruit set.
Management:
- Spray wettable sulphur 50 WP @ 2 g/litre.
- Spray dicofol 18.5 EC @ 2.5 ml/litre.
Summary: Integrated Pest Management in Tomato
- Monitor pest populations regularly using traps and field scouting.
- Adopt cultural, mechanical, biological, and chemical control methods in combination.
- Use resistant varieties and maintain field hygiene.
- Apply pesticides judiciously to avoid resistance and residue problems.
- Promote natural enemies and minimize ecological disruption.
Objective Questions
Q1. Which family does the tomato fruit borer, Helicoverpa armigera, belong to?
A. Noctuidae
B. Gelechidae
C. Agromyzidae
D. Thripidae
Answer: A
Q2. What is the recommended ratio of American tall marigold to tomato seedlings for managing tomato fruit borer?
A. 1:10
B. 1:16
C. 1:20
D. 1:25
Answer: B
Q3. Which insecticide and dose is recommended for chemical control of whitefly on tomato?
A. Indoxacarb 8 ml/10 lit
B. Dimethoate 1.0 ml/lit
C. Flubendiamide 5 g/10 lit
D. Azadirachtin 2.0 ml/lit
Answer: B
Q4. Which pest is a vector of tomato leaf curl disease?
A. Tuta absoluta
B. Bemisia tabaci
C. Liriomyza trifolii
D. Aphis gossypii
Answer: B
Q5. What is the scientific name of the serpentine leaf miner?
A. Tuta absoluta
B. Liriomyza trifolii
C. Helicoverpa armigera
D. Thrips tabaci
Answer: B
Q6. Which biological control agent is released at 1 lakh/ha for tomato fruit borer management?
A. Chrysoperla carnea
B. Trichogramma pretiosum
C. Trichogramma chilonis
D. Bacillus thuringiensis
Answer: B
Q7. Which pest's larvae are described as minute orange yellowish apodous maggots?
A. Tomato fruit borer
B. Serpentine leaf miner
C. Red spider mite
D. Aphids
Answer: B
Q8. Which chemical is recommended at 2g/lit for controlling red spider mite?
A. Dicofol 18.5 EC
B. Wettable sulphur 50 WP
C. Flubendiamide 20 WG
D. Novaluron 10% EC
Answer: B
Q9. Which pest is identified by dark coloured adults with fringed wings?
A. Aphids
B. Thrips
C. Whitefly
D. Red spider mite
Answer: B
Q10. Which pest causes silvery streaks on tomato leaf surfaces and is a vector of tomato spotted wilt virus?
A. Thrips tabaci
B. Bemisia tabaci
C. Tetranychus spp
D. Myzus persicae
Answer: A
This presentation provides an overview of major insect pests affecting tomato crops, focusing on their identification, nature of damage, life cycle, and integrated management strategies. Emphasis is placed on the economic impact, pest biology, and effective control measures, including biological, cultural, and chemical methods. Key topics include the tomato fruit borer, leaf miner, whitefly, aphids, thrips, and red spider mite, which are critical for understanding pest management in tomato cultivation. Important academic keywords include pest identification, life cycle, damage symptoms, integrated pest management, and chemical control.
Introduction to Tomato Pests
- Tomato is susceptible to several insect pests causing significant yield loss.
- Major pests include fruit borer, leaf miner, whitefly, aphids, thrips, and red spider mite.
- Effective management requires correct identification and understanding of pest biology.
Tomato Fruit Borer (Helicoverpa armigera)
Taxonomy:
- Family: Noctuidae; Order: Lepidoptera
Economic Importance:
- Serious pest in tropical and subtropical regions.
- Damages tomato, tur, gram, and other crops.
Identification:
- Caterpillar: Varying color, radiating hairs, brown to greenish with dark lines.
- Moth: Medium-sized, light yellowish brown, forewings with dark spot, hindwings pale with black border.
Tomato Fruit Borer – Life Cycle & Damage
Life Cycle:
- Eggs laid on tender plant parts.
- Larval stage lasts 18–25 days; pupates in soil.
- Total life cycle: 30–40 days.
Nature of Damage:
- Young larvae feed on foliage; older larvae bore into fruits.
- Circular holes in fruits; internal feeding leads to secondary infections.
- One larva can damage 2–8 fruits.
Tomato Fruit Borer – Management
Cultural & Mechanical:
- Collect and destroy infested fruits and larvae.
- Deep ploughing after harvest to expose pupae.
- Intercrop with marigold (1:16 rows) to attract adults.
Biological:
- Release Trichogramma spp. and Chrysoperla carnea.
- Spray Bacillus thuringiensis (2g/lit) or HaNPV (250 LE/ha).
Chemical:
- Use pheromone traps (Helilure) at 12/ha.
- Spray recommended insecticides: Azadirachtin, Indoxacarb, Flubendiamide, Novaluron, Phosalone, Quinalphos.
Serpentine Leaf Miner (Liriomyza trifolii)
Taxonomy:
- Family: Agromyzidae; Order: Diptera
Identification:
- Larva: Minute, orange-yellow, apodous maggots.
- Adult: Pale yellow, small fly.
Life Cycle:
- Eggs laid singly on upper leaf surface.
- Larval period: 7–10 days; pupates in soil or leaves.
- Total life cycle: ~3 weeks.
Damage:
- Larvae mine between leaf epidermis, causing serpentine trails.
- Severe cases cause leaf drying and drop.
Serpentine Leaf Miner – Management
- Collect and destroy mined leaves.
- Spray neem seed kernel extract (NSKE) 5%.
- Practice crop rotation and avoid overuse of insecticides to conserve natural enemies.
Tomato Leaf Miner (Tuta absoluta)
Taxonomy:
- Family: Gelechiidae; Order: Lepidoptera
Identification:
- Small, greyish-brown moth; larvae mine leaves, stems, and fruits.
Damage:
- Leaf mines, galleries in stems, and fruit damage.
- Can cause severe yield loss if unmanaged.
Management:
- Use pheromone traps for monitoring.
- Release natural enemies (Trichogramma spp.).
- Apply Bacillus thuringiensis or selective insecticides as needed.
Whitefly (Bemisia tabaci)
Taxonomy:
- Family: Aleyrodidae; Order: Hemiptera
Identification:
- Eggs: Pear-shaped, light yellow.
- Nymphs: Oval, scale-like, greenish white.
- Adults: Tiny, white, scale-like.
Damage:
- Nymphs and adults suck sap, causing chlorosis and leaf curling.
- Vector of tomato leaf curl virus.
Whitefly – Management
- Uproot and destroy infected plants.
- Remove alternate weed hosts (e.g., Abutilon indicum).
- Use yellow sticky traps (12/ha).
- Apply carbofuran 3% G @ 40 kg/ha or recommended insecticides: Dimethoate, Malathion, Oxydemeton-methyl, Thiamethoxam.
Aphids (Aphis gossypii, Myzus persicae)
Taxonomy:
- Family: Aphididae; Order: Hemiptera
Identification:
- Small, soft-bodied insects, green or black.
Damage:
- Nymphs and adults suck sap, causing yellowing, deformation, and drying.
- Honeydew secretion leads to sooty mould, reducing photosynthesis.
Management:
- Seed treatment with imidacloprid or thiamethoxam.
- Use yellow sticky traps.
- Encourage natural predators (ladybird beetles, lacewings).
Thrips (Thrips tabaci)
Taxonomy:
- Family: Thripidae; Order: Thysanoptera
Identification:
- Nymphs: Yellowish; Adults: Dark with fringed wings.
Damage:
- Silvery streaks on leaves, bud necrosis, flower drop.
- Vector of tomato spotted wilt virus.
Management:
- Uproot and destroy diseased plants.
- Use yellow sticky traps (15/ha).
- Release Chrysoperla carnea larvae (10,000/ha).
- Spray methyl demeton or dimethoate as needed.
Red Spider Mite (Tetranychus spp.)
Taxonomy:
- Family: Tetranychidae; Order: Acarina
Identification:
- Eggs: Hyaline, globular, laid in masses.
- Nymphs: Yellowish; Adults: Small, red.
Damage:
- Leaves turn reddish-brown, bronzed, and dry.
- Webbing on leaves; reduced flower and fruit set.
Management:
- Spray wettable sulphur 50 WP (2g/lit) or dicofol 18.5 EC (2.5 ml/lit).
Summary: Integrated Pest Management in Tomato
- Combine cultural, biological, and chemical methods for effective pest control.
- Monitor pest populations regularly using traps and field scouting.
- Promote use of resistant varieties and natural enemies.
- Apply insecticides judiciously to avoid resistance and conserve beneficial insects.
Objective Questions
Q1. Which family does the tomato fruit borer, Helicoverpa armigera, belong to?
A. Noctuidae
B. Gelechidae
C. Agromyzidae
D. Aleurodidae
Answer: A
Q2. What is the recommended ratio of American tall marigold to tomato rows for managing tomato fruit borer?
A. 1:10
B. 1:16
C. 1:20
D. 1:25
Answer: B
Q3. Which insecticide is recommended at a dose of 7.5 ml/10 lit for tomato fruit borer control?
A. Indoxacarb
B. Flubendiamide
C. Novaluron
D. Phosalone
Answer: C
Q4. Which pest is identified by minute orange yellowish apodous maggots as larvae?
A. Tomato fruit borer
B. Serpentine leaf miner
C. Whitefly
D. Aphids
Answer: B
Q5. Which pest is a vector of tomato leaf curl disease?
A. Thrips tabaci
B. Bemisia tabaci
C. Liriomyza trifolii
D. Tuta absoluta
Answer: B
Q6. Which control measure is NOT recommended for aphid management in tomato?
A. Seed treatment with imidachloprid
B. Use of yellow sticky trap
C. Spray methyl demeton
D. Thiamethoxam 5 kg/seed
Answer: C
Q7. Which pest causes silvery streaks on leaf surface and is a vector of tomato spotted wilt virus?
A. Red spider mite
B. Thrips tabaci
C. Whitefly
D. Aphids
Answer: B
Q8. Which chemical is recommended at 2g/lit for controlling red spider mite?
A. Dicofol 18.5 EC
B. Wettable sulphur 50 WP
C. Dimethoate 30% EC
D. Malathion 50% EC
Answer: B
Q9. Which order does the tomato leaf miner, Tuta absoluta, belong to?
A. Hemiptera
B. Diptera
C. Lepidoptera
D. Thysonoptera
Answer: C
Q10. Which pest's nymphs and adults suck sap, causing yellowing and deformation of tomato plants?
A. Whitefly
B. Aphids
C. Thrips
D. Red spider mite
Answer: B
This presentation provides an overview of major insect pests affecting tomato crops, focusing on their identification, nature of damage, life cycles, and integrated management strategies. Emphasis is placed on the economic impact, pest biology, and effective control measures, including biological, cultural, and chemical methods. Key concepts include pest identification, damage symptoms, life cycle, integrated pest management, and chemical control.
Introduction to Tomato Pests
- Tomato is affected by several major insect pests causing significant yield loss.
- Pests attack various plant parts: leaves, stems, flowers, and fruits.
- Effective management requires understanding pest biology and damage symptoms.
Tomato Fruit Borer (Helicoverpa armigera)
Taxonomy:
- Family: Noctuidae; Order: Lepidoptera
Economic Importance:
- Serious pest in tropical and subtropical regions.
- Also attacks other crops like pigeon pea and chickpea.
Identification:
- Caterpillar: Variable color, radiating hairs, greenish with dark lines.
- Moth: Medium-sized, light brown, forewings with dark spot, smoky hindwings.
Tomato Fruit Borer – Biology and Damage
Life Cycle:
- Eggs laid on tender plant parts.
- Larval stage lasts 18–25 days; pupates in soil.
- Complete life cycle: 30–40 days.
Nature of Damage:
- Young larvae feed on foliage; older larvae bore into fruits.
- Bore circular holes, feed inside fruits, causing secondary infections.
- One larva can damage multiple fruits.
Tomato Fruit Borer – Management
Cultural Control:
- Collect and destroy infested fruits and larvae.
- Deep ploughing after harvest to expose pupae.
- Intercrop with marigold (1:16 ratio) to attract egg-laying adults.
Biological Control:
- Release Trichogramma spp. and Chrysoperla carnea.
- Spray Bacillus thuringiensis or HaNPV.
Chemical Control:
- Use pheromone traps (Helilure) at 12/ha.
- Apply insecticides: Azadirachtin, Indoxacarb, Flubendiamide, Novaluron, Phosalone, Quinalphos as per recommended doses.
Serpentine Leaf Miner (Liriomyza trifolii)
Taxonomy:
- Family: Agromyzidae; Order: Diptera
Identification:
- Larva: Minute, orange-yellow, apodous maggots.
- Adult: Pale yellow, small fly.
Life Cycle:
- Eggs laid singly on upper leaf surface.
- Larval period: 7–10 days; pupation in soil or leaves.
- Total life cycle: ~3 weeks.
Nature of Damage:
- Larvae mine between leaf epidermis, creating serpentine trails.
- Severe infestation leads to leaf drying and drop.
Management:
- Remove and destroy mined leaves.
- Spray neem seed kernel extract (NSKE) 5%.
Tomato Leaf Miner (Tuta absoluta)
Taxonomy:
- Family: Gelechiidae; Order: Lepidoptera
Nature of Damage:
- Larvae mine leaves, stems, and fruits, causing blotches and galleries.
- Leads to fruit damage and yield loss.
Management:
- Use pheromone traps for monitoring and mass trapping.
- Release natural enemies (Trichogramma spp.).
- Apply Bacillus thuringiensis or selective insecticides as needed.
Whitefly (Bemisia tabaci)
Taxonomy:
- Family: Aleyrodidae; Order: Hemiptera
Identification:
- Egg: Pear-shaped, light yellow.
- Nymph: Oval, scale-like, greenish-white.
- Adult: Tiny, white, scale-like.
Nature of Damage:
- Nymphs and adults suck sap, causing chlorosis and leaf curling.
- Vector of tomato leaf curl virus.
Management:
- Remove and destroy infected plants and weeds.
- Use yellow sticky traps (12/ha).
- Apply carbofuran or recommended insecticides: Dimethoate, Malathion, Oxydemeton-methyl, Thiamethoxam.
Aphids (Aphis gossypii, Myzus persicae)
Taxonomy:
- Family: Aphididae; Order: Hemiptera
Nature of Damage:
- Nymphs and adults suck sap, causing yellowing and deformation.
- Honeydew secretion leads to sooty mould growth, reducing photosynthesis.
Management:
- Seed treatment with imidacloprid or thiamethoxam.
- Use yellow sticky traps.
Thrips (Thrips tabaci)
Taxonomy:
- Family: Thripidae; Order: Thysanoptera
Identification:
- Nymphs: Yellowish; Adults: Dark with fringed wings.
Nature of Damage:
- Silvery streaks on leaves, bud necrosis, flower drop.
- Vector of tomato spotted wilt virus.
Management:
- Uproot and destroy diseased plants.
- Use yellow sticky traps (15/ha).
- Release Chrysoperla carnea larvae.
- Spray methyl demeton or dimethoate as per recommendations.
Red Spider Mite (Tetranychus spp.)
Taxonomy:
- Family: Tetranychidae; Order: Acarina
Identification:
- Eggs: Hyaline, globular, laid in masses.
- Nymphs: Yellowish; Adults: Small, red.
Nature of Damage:
- Leaves turn reddish-brown, bronzed, and dry.
- Webbing on leaves; affects flower and fruit formation.
Management:
- Spray wettable sulphur (50 WP, 2g/lit) or dicofol (18.5 EC, 2.5 ml/lit).
Summary: Integrated Pest Management in Tomato
- Combine cultural, biological, and chemical methods for effective pest control.
- Monitor fields regularly for early pest detection.
- Use resistant varieties and crop rotation.
- Promote natural enemies and minimize pesticide use.
Objective Questions
Q1. Which family does the tomato fruit borer, Helicoverpa armigera, belong to?
A. Noctuidae
B. Gelechidae
C. Agromyzidae
D. Thripidae
Answer: A
Q2. What is the recommended ratio of American tall marigold to tomato rows for managing tomato fruit borer?
A. 1:10
B. 1:16
C. 1:20
D. 1:25
Answer: B
Q3. Which insecticide is recommended at a dose of 8 ml/10 lit for tomato fruit borer control?
A. Flubendiamide 20 WG
B. Indoxacarb 14.5% SC
C. Novaluron 10% EC
D. Azadirachtin 1.0% EC
Answer: B
Q4. Which pest is identified by minute orange yellowish apodous maggots as larvae?
A. Helicoverpa armigera
B. Liriomyza trifolii
C. Tuta absoluta
D. Bemisia tabaci
Answer: B
Q5. Which pest is the vector of tomato leaf curl disease?
A. Aphis gossypii
B. Bemisia tabaci
C. Tuta absoluta
D. Thrips tabaci
Answer: B
Q6. Which chemical is recommended for spraying against red spider mite at 2g/lit?
A. Dicofol 18.5 EC
B. Wettable sulphur 50 WP
C. Dimethoate 30% EC
D. Malathion 50% EC
Answer: B
Q7. Which pest's nymphs and adults cause silvery streaks and bud necrosis on tomato?
A. Aphis gossypii
B. Tetranychus spp
C. Thrips tabaci
D. Liriomyza trifolii
Answer: C
Q8. Which biological control agent is released at 1 lakh/ha for tomato fruit borer management?
A. Trichogramma chilonis
B. Trichogramma pretiosum
C. Chrysoperla carnea
D. Bacillus thuringiensis
Answer: B
Q9. Which order does the tomato leaf miner, Tuta absoluta, belong to?
A. Diptera
B. Hemiptera
C. Lepidoptera
D. Acarina
Answer: C
Q10. Which pest's infestation leads to sooty mould growth due to honeydew secretion?
A. Thrips tabaci
B. Tetranychus spp
C. Aphis gossypii
D. Liriomyza trifolii
Answer: C
This presentation provides an overview of major insect pests affecting tomato crops, focusing on their identification, life cycle, nature of damage, and management strategies. Emphasis is placed on integrated pest management, including biological, cultural, and chemical control methods. Key pests discussed include the tomato fruit borer, serpentine leaf miner, whitefly, aphids, thrips, and red spider mite. Understanding pest biology and damage symptoms is essential for effective crop protection and sustainable tomato production. Important academic keywords include integrated pest management, life cycle, damage symptoms, biological control, and chemical control.
Introduction to Tomato Pests
- Tomato is susceptible to several insect pests causing significant yield loss.
- Major pests include fruit borer, leaf miner, whitefly, aphids, thrips, and red spider mite.
- Effective management requires understanding pest biology and damage symptoms.
- Integrated pest management (IPM) combines cultural, biological, and chemical methods.
Tomato Fruit Borer (Helicoverpa armigera)
Taxonomy:
- Family: Noctuidae; Order: Lepidoptera
Identification:
- Caterpillars: Varying color, radiating hairs, brown to greenish with dark lines.
- Moth: Medium-sized, light yellowish brown, forewings with dark spot, hindwings pale with black border.
Life Cycle:
- Eggs laid on tender plant parts.
- Larval period: 18–25 days; pupates in soil.
- Total life cycle: ~30–40 days.
Tomato Fruit Borer – Nature of Damage & Symptoms
- Young larvae feed on foliage; mature larvae bore into fruits.
- Circular holes on fruits; larvae feed inside, causing internal damage.
- Damaged fruits often infected by secondary pathogens.
- One larva may damage multiple fruits (2–8).
Tomato Fruit Borer – Management
Cultural & Mechanical:
- Collect and destroy infested fruits and larvae.
- Deep ploughing after harvest exposes pupae to predators.
- Intercrop with marigold (1:16 ratio with tomato).
Biological:
- Release Trichogramma spp. and Chrysoperla carnea.
- Spray Bacillus thuringiensis (2g/litre) or HaNPV @ 250 LE/ha.
Chemical:
- Use pheromone traps (Helilure) @ 12/ha.
- Spray recommended insecticides: Azadirachtin, Indoxacarb, Flubendiamide, Novaluron, Phosalone, Quinalphos (as per label rates).
Serpentine Leaf Miner (Liriomyza trifolii)
Taxonomy:
- Family: Agromyzidae; Order: Diptera
Identification:
- Larva: Minute, orange-yellow, apodous maggot.
- Adult: Pale yellow, small fly.
Life Cycle:
- Eggs laid singly on upper leaf surface.
- Larval period: 7–10 days; pupation in soil or leaves.
- Total life cycle: ~3 weeks.
Serpentine Leaf Miner – Damage & Management
Nature of Damage:
- Larvae mine between leaf epidermal layers, creating serpentine trails.
- Severe infestation causes leaf drying and drop.
Management:
- Collect and destroy mined leaves.
- Spray neem seed kernel extract (NSKE) 5%.
Whitefly (Bemisia tabaci)
Taxonomy:
- Family: Aleyrodidae; Order: Hemiptera
Identification:
- Eggs: Pear-shaped, light yellow.
- Nymphs: Oval, scale-like, greenish-white.
- Adults: Tiny, white, scale-like.
Nature of Damage:
- Nymphs and adults suck sap, causing chlorosis and leaf curling.
- Vector of tomato leaf curl virus.
Whitefly – Management
- Uproot and destroy virus-infected plants.
- Remove alternate weed hosts (e.g., Abutilon indicum).
- Use yellow sticky traps (12/ha).
- Apply carbofuran 3% G @ 40 kg/ha.
- Spray insecticides: Dimethoate, Malathion, Oxydemeton-methyl, Thiamethoxam (as per label rates).
Aphids (Aphis gossypii, Myzus persicae)
Taxonomy:
- Family: Aphididae; Order: Hemiptera
Nature of Damage:
- Nymphs and adults suck sap, causing yellowing and deformation.
- Honeydew secretion promotes sooty mould, reducing photosynthesis.
Management:
- Seed treatment with imidacloprid or thiamethoxam.
- Use yellow sticky traps.
Thrips (Thrips tabaci)
Taxonomy:
- Family: Thripidae; Order: Thysanoptera
Identification:
- Nymphs: Yellowish; Adults: Dark with fringed wings.
Nature of Damage:
- Silvery streaks on leaves, bud necrosis, flower drop.
- Vector of tomato spotted wilt virus.
Management:
- Remove and destroy diseased plants.
- Use yellow sticky traps (15/ha).
- Release Chrysoperla carnea larvae (10,000/ha).
- Spray methyl demeton or dimethoate (as per label rates).
Red Spider Mite (Tetranychus spp.)
Taxonomy:
- Family: Tetranychidae; Order: Acarina
Identification:
- Eggs: Hyaline, globular, laid in masses.
- Nymphs: Yellowish; Adults: Small, red.
Nature of Damage:
- Leaves turn reddish-brown, bronzed; webbing present.
- Severe infestation leads to leaf drying and reduced fruit set.
Management:
- Spray wettable sulphur 50 WP (2g/litre).
- Spray dicofol 18.5 EC (2.5 ml/litre).
Summary: Integrated Pest Management in Tomato
- Combine cultural, mechanical, biological, and chemical methods for sustainable pest control.
- Monitor pest populations regularly for timely intervention.
- Promote use of resistant varieties and natural enemies.
- Minimize pesticide use to prevent resistance and protect beneficial organisms.
Objective Questions
Q1. Which family does the tomato fruit borer, Helicoverpa armigera, belong to?
A. Noctuidae
B. Gelechidae
C. Agromyzidae
D. Thripidae
Answer: A
Q2. What is the recommended row ratio for growing American tall marigold and tomato seedlings for fruit borer management?
A. 1:10
B. 1:16
C. 1:20
D. 1:25
Answer: B
Q3. Which insecticide is recommended at a dose of 8 ml/10 lit for tomato fruit borer control?
A. Flubendiamide 20 WG
B. Indoxacarb 14.5% SC
C. Novaluron 10% EC
D. Phosalone 35% EC
Answer: B
Q4. Which pest is identified by minute orange yellowish apodous maggots as larvae?
A. Tomato fruit borer
B. Serpentine leaf miner
C. Whitefly
D. Thrips
Answer: B
Q5. Which pest is a vector of tomato leaf curl disease?
A. Aphids
B. Whitefly
C. Red spider mite
D. Thrips
Answer: B
Q6. Which chemical is recommended for spraying at 2g/lit to control red spider mite?
A. Dicofol 18.5 EC
B. Wettable sulphur 50 WP
C. Carbofuran 3% G
D. Dimethoate 30% EC
Answer: B
Q7. Which pest's nymphs and adults suck sap and secrete honeydew leading to sooty mould?
A. Whitefly
B. Aphids
C. Thrips
D. Red spider mite
Answer: B
Q8. Which order does Thrips tabaci belong to?
A. Hemiptera
B. Lepidoptera
C. Thysonoptera
D. Diptera
Answer: C
Q9. Which biological control agent is released at 1 lakh/ha for tomato fruit borer management?
A. Trichogramma chilonis
B. Trichogramma pretiosum
C. Chrysoperla carnea
D. Bacillus thuringiensis
Answer: B
Q10. Which insecticide is applied at 1.0 ml/lit for whitefly control?
A. Malathion 50% EC
B. Oxydemeton-Methyl 25% EC
C. Dimethoate 30% EC
D. Thiamethoxam 25% WG
Answer: C
This presentation covers major diseases of okra, focusing on their cause, etiology, symptoms, disease cycle, and management. Key diseases include Powdery Mildew, Fusarium Wilt, Alternaria Leaf Spot, and Yellow Vein Mosaic. Understanding the pathogens, epidemiology, and integrated management strategies is essential for effective disease control and sustainable okra production.
Introduction to Okra Diseases
- Okra (Abelmoschus esculentus) is affected by several fungal and viral diseases.
- Major diseases: Powdery mildew, Fusarium wilt, Alternaria leaf spot, Yellow vein mosaic.
- Effective management requires knowledge of pathogens, symptoms, and control measures.
Powdery Mildew – Pathogen, Symptoms, Disease Cycle, Management
Pathogen: Erysiphe cichoracearum
Symptoms:
- White or grayish powdery growth on upper leaf surfaces, later covering entire leaf.
- Lower leaf surfaces may also be infected.
- Affected leaves dry and fall prematurely, reducing yield.
Disease Cycle:
- Overwinters as dormant mycelium or cleistothecia on infected leaves.
- Secondary spread by wind-borne conidia.
- Favored by 60–80% relative humidity and dry conditions.
Management:
- Spray fungicides: wettable sulphur (0.25%), dinocap (0.1%), carbendazim (0.1%), hexaconazole (0.05%), or difenoconazole (0.05%).
- Repeat sprays at 10–14 day intervals.
- Biocontrol: Ampelomyces quisqualis, Trichoderma spp., Bacillus subtilis.
- Use azadirachtin (0.03% EC) as needed.
Fusarium Wilt – Pathogen, Etiology, Symptoms, Disease Cycle, Management
Pathogen: Fusarium oxysporum f. sp. vasinfectum
Symptoms:
- Yellowing, stunting, wilting, and rolling of leaves.
- Dark brown vascular discoloration in stems.
- Severe cases: stem blackening and plant death.
Etiology:
- Produces hyaline mycelium, microconidia (single/two-celled), macroconidia (3–4 septa), and chlamydospores.
Disease Cycle:
- Survives as chlamydospores in soil and infected seeds.
- Optimum temperature for growth: 25°C; disease develops at 22–28°C.
Management:
- Use healthy, treated seed (carbendazim 0.2%).
- Practice crop rotation and soil solarization.
- Remove and destroy affected plants.
- Grow resistant varieties: CS-3232, CS-8899, IS-6653, IS-7194, Pusa Makhameli, Pusa Sawani.
Alternaria Leaf Spot – Pathogen, Etiology, Symptoms, Disease Cycle, Management
Pathogen: Alternaria alternata
Symptoms:
- Brown leaf spots with pale margins and yellow halos.
- Lesions enlarge, show concentric rings, and coalesce.
- Severe infection causes leaf drying and defoliation.
Etiology:
- Produces cylindrical conidiophores and brown, muriform conidia with transverse and longitudinal septa.
Disease Cycle:
- Survives in infected plant debris, weed hosts, and seeds.
- Secondary spread by wind-borne conidia.
Management:
- Remove and destroy infected debris and weeds.
- Seed treatment with Thiram (6 g/kg).
- Spray Mancozeb (0.2%) after disease appearance.
Yellow Vein Mosaic – Pathogen, Symptoms, Disease Cycle, Management
Pathogen: Yellow Vein Mosaic Virus (YVMV)
Symptoms:
- Vein yellowing and thickening, forming a network pattern.
- Leaves become chlorotic and yellow under severe infection.
- Plants are stunted with small, pale fruits.
Disease Cycle:
- Transmitted by whitefly (Bemisia tabaci) in a persistent manner.
- Wild and cultivated plants act as inoculum sources.
- Favored by dry, hot weather with low rainfall.
Management:
- Destroy wild hosts and avoid mixed cropping with pumpkin.
- Adjust sowing dates to avoid peak whitefly populations.
- Remove infected plants up to 55 days after sowing.
- Grow resistant cultivars: Punjab Padmini, Punjab-8, Prabhani Kranti, Hissar Unnat.
- Spray systemic insecticides (cypermethrin, deltamethrin, triazophos) to control vectors.
Summary: Integrated Disease Management in Okra
- Use disease-free, treated seeds and resistant varieties.
- Practice crop rotation, field sanitation, and timely removal of infected plants.
- Apply recommended fungicides and insecticides judiciously.
- Adopt biological control agents where feasible.
- Monitor fields regularly for early detection and management.
Objective Questions
Q1. Which causal organism is responsible for powdery mildew in okra?
A. Erysiphe cichoracearum
B. Fusarium oxysporum f. sp. vasinfectum
C. Alternaria alternata
D. Yellow Vein Mosaic Virus
Answer: A
Q2. What is the optimum temperature range for Fusarium wilt disease development in okra?
A. 15–20°C
B. 22–28°C
C. 30–35°C
D. 10–15°C
Answer: B
Q3. Which structure allows Fusarium oxysporum to survive in soil for long periods?
A. Cleistothecia
B. Chlamydospores
C. Conidiophores
D. Sclerotia
Answer: B
Q4. Which of the following is NOT a recommended management practice for yellow vein mosaic in okra?
A. Spraying systemic insecticides
B. Mixed cropping with pumpkin
C. Removal of wild hosts
D. Use of resistant cultivars
Answer: B
Q5. Which symptom is characteristic of Alternaria leaf spot in okra?
A. White powdery growth on leaves
B. Brown spots with concentric rings
C. Vein yellowing and thickening
D. Blackening of stem
Answer: B
Q6. Which fungicide is recommended for seed treatment against Alternaria leaf spot in okra?
A. Carbendazim
B. Mancozeb
C. Thiram
D. Wettable sulphur
Answer: C
Q7. What is the main vector for transmission of yellow vein mosaic virus in okra?
A. Aphid
B. Thrips
C. White fly
D. Leafhopper
Answer: C
Q8. Which of the following is a biological control agent used against powdery mildew in okra?
A. Bacillus subtilis
B. Thiram
C. Cypermethrin
D. Deltamethrin
Answer: A
Q9. Which symptom is NOT associated with Fusarium wilt in okra?
A. Yellowing and stunting
B. Dark brown vascular discoloration
C. Brown spots with yellow halo
D. Wilting and rolling of leaves
Answer: C
Q10. Which of the following is a resistant variety for Fusarium wilt in okra?
A. Punjab Padmini
B. CS-3232
C. Prabhani Kranti
D. Hissar Unnat
Answer: B
This presentation covers major diseases affecting cabbage and cauliflower, focusing on their identification, causal organisms, symptoms, and integrated management. Emphasis is placed on effective integrated pest management (IPM) strategies, including cultural practices, chemical control, biological control, and resistant varieties. Understanding these aspects is essential for sustainable crop production and minimizing yield losses.
Introduction to Cabbage and Cauliflower Diseases
- Cabbage and cauliflower are susceptible to several fungal, bacterial, and viral diseases.
- Diseases can cause significant yield and quality losses.
- Integrated Pest Management (IPM) combines multiple strategies for effective disease control.
- Accurate identification is crucial for selecting appropriate management methods.
Damping-off
Pathogen: Pythium spp., Rhizoctonia solani, Fusarium spp.
Nature: Soil-borne fungal pathogens affecting seedlings.
Symptoms:
- Seedlings rot at soil level and collapse.
- Poor germination and patchy stands in nursery beds.
Management:
- Use well-drained, sterilized nursery beds.
- Avoid overwatering.
- Treat seeds with fungicides (e.g., Thiram, Captan).
- Practice crop rotation.
Downy Mildew
Pathogen: Hyaloperonospora parasitica
Nature: Oomycete fungus, favored by cool, moist conditions.
Symptoms:
- Yellow spots on upper leaf surface.
- White, downy growth on lower leaf surface.
- Stunted plant growth.
Management:
- Use resistant varieties.
- Ensure good field drainage and air circulation.
- Apply fungicides (e.g., Metalaxyl, Mancozeb) as needed.
Black Rot
Pathogen: Xanthomonas campestris pv. campestris
Nature: Bacterial disease, spread by water and infected seed.
Symptoms:
- V-shaped yellow lesions at leaf margins.
- Blackening of veins.
- Wilting and stunted growth.
Management:
- Use certified disease-free seeds.
- Practice crop rotation (2–3 years).
- Remove and destroy infected plants.
- Apply copper-based bactericides if needed.
Alternaria Leaf Spot (Alternaria Blight)
Pathogen: Alternaria brassicae, Alternaria brassicicola
Nature: Fungal disease, favored by humid conditions.
Symptoms:
- Dark brown to black concentric spots on leaves.
- Leaf blight and defoliation in severe cases.
Management:
- Use disease-free seeds and resistant varieties.
- Remove crop debris after harvest.
- Apply fungicides (e.g., Mancozeb, Chlorothalonil).
Clubroot
Pathogen: Plasmodiophora brassicae
Nature: Soil-borne protist, persists for years in soil.
Symptoms:
- Swollen, club-shaped roots.
- Wilting and stunted growth, especially in acidic soils.
Management:
- Practice long crop rotation (4–7 years).
- Apply lime to raise soil pH above 7.0.
- Use resistant varieties where available.
Integrated Disease Management Strategies
- Use certified, disease-free seeds and resistant varieties.
- Practice crop rotation and field sanitation.
- Monitor fields regularly for early disease detection.
- Apply biological control agents (e.g., Trichoderma spp.).
- Use chemical control judiciously, following recommended guidelines.
Summary of Major Diseases and Management
| Disease |
Pathogen |
Key Management |
| Damping-off |
Pythium, Rhizoctonia, Fusarium |
Seed treatment, drainage, crop rotation |
| Downy Mildew |
Hyaloperonospora parasitica |
Resistant varieties, fungicides |
| Black Rot |
Xanthomonas campestris |
Clean seed, sanitation, copper sprays |
| Alternaria Leaf Spot |
Alternaria spp. |
Resistant varieties, fungicides |
| Clubroot |
Plasmodiophora brassicae |
Crop rotation, liming, resistant varieties |
Objective Questions
Q1. Which crops are the focus of the discussed IPM strategies?
A. Tomato and potato
B. Cabbage and cauliflower
C. Onion and garlic
D. Pea and bean
Answer: B
Q2. What does IPM stand for in the context of crop production?
A. Integrated Plant Management
B. Integrated Pest Management
C. Intensive Pest Management
D. Improved Plant Management
Answer: B
Q3. The diseases discussed are related to which type of crops?
A. Cereals
B. Pulses
C. Vegetables
D. Fruits
Answer: C
Q4. Which of the following is NOT a language option mentioned in the text?
A. French
B. Hindi
C. Bengali
D. Tamil
Answer: A
Q5. The text is primarily concerned with which aspect of agriculture?
A. Harvesting techniques
B. Disease management
C. Irrigation methods
D. Fertilizer application
Answer: B
Q6. Which vegetable is paired with cabbage in the IPM strategies?
A. Broccoli
B. Cauliflower
C. Carrot
D. Spinach
Answer: B
Q7. What is the main goal of IPM in vegetable crops?
A. Increase pesticide use
B. Manage pests and diseases
C. Improve taste
D. Enhance color
Answer: B
Q8. Which of the following is NOT mentioned as a crop in the text?
A. Cabbage
B. Cauliflower
C. Potato
D. None of the above
Answer: C
Q9. The discussed IPM strategies are specifically for which group?
A. Fruits
B. Vegetables
C. Grains
D. Oilseeds
Answer: B
Q10. The text refers to management strategies for diseases in which crops?
A. Cabbage and cauliflower
B. Wheat and rice
C. Tomato and brinjal
D. Maize and sorghum
Answer: A