IMPORTANT PESTS AND DISEASES OF TOMATO

Serpentine leaf miner: Liriomyza trifolii

Symptoms of damage:

• Leaves with serpentine mines

• Drying and dropping of leaves

Identification of pest:

• Larva: Minute orange yellowish apodous maggots

• Pupa: Yellowish brown pupates within mines

• Adult: Pale yellow in colour

Management:

• Collect and destroy mined leaves

• Spray NSKE 5%

Symptoms of damage:

• Young larvae feed on tender foliage

• Mature larvae bore circular holes

Thrust only a part of its body into fruit and eat the inner content

Identification of pest:

• Eggs: Eggs are sculptured and creamy white in colour, laid singly

• Larva: Shows colour variation from greenish to brown. It has dark brown grey lines on the body with lateral white lines and also has dark band

• Pupa: Brown in colour, occurs in soil, leaf, pod and crop debris

• Adult: Female light pale brownish yellow stout moth, Male – Pale greenish moth V shaped speck.

  • Forewing: olive green to pale brown with a dark brown circular spot in the centre

  • Hindwing: is pale smoky white with a broad blackish outer margin

Management:

• Collect and destroy the infected fruits and grown up larvae

• Spray Bacillus thuringiensis 2g/lit or any one of the following insecticide

Whitefly: Bemisia tabaci Symptoms of damage:

• Chlorotic spots

• Yellowing

• Downward curling and drying of leaves

• Vector of tomato leaf curl disease

Identification of pest

• Egg: Pear shaped, light yellowish, stalked

• Nymph: On hatching - Oval, scale-like, greenish white

• Adult: White, tiny, scale-like adults

Management:

• Uproot and destroy the diseased leaf curl plants

• Use nitrogen and irrigation judiciously.

• Remove alternate weed host Abutilon indicum

• Use yellow sticky traps at 12/ha to attract and kill insects.

• Apply carbofuran 3% G @ 40 kg /ha or spray any one of the following insecticides

Leaf curl: Tomato leaf curl virus (ToLCV)

Symptom

• The new growth of plants with tomato yellow leaf curl has reduced internodes, giving the plant a stunted appearance

• The new leaves are also greatly reduced in size and wrinkled, are yellowed between the veins, and have margins that curl upward, giving them a cup-like appearance

• Flowers may appear but usually will drop before fruit is set

Management

• Keep yellow sticky traps @ 12/ha to monitor the white fly.

• Raise barrier crops-cereals around the field.

• Removal of weed host. Protected nursery in net house or green house.

• Spray Imidachloprid 0.05 % or

• Dimethoate 0.05% @ 15, 25, 45 days after transplanting to control vector.

Spotted wilt: Tomato spotted wilt disease (TSWV), Groundnut bud necrosis virus

Symptom

• It causes streaking of the leaves, stems and fruits. Numerous small, dark, circular spots appear on younger leaves.

• Leaves may have a bronzed appearance and later turn dark brown and wither.

• Fruits show numerous spots about one-half inch in diameter with concentric, circular markings. On ripe fruit, these markings are alternate bands of red and yellow.

• The spotted wilt virus is transmitted through thrips (Thrips tabaci, Frankliniella schultzi and F.occidentalis).

Management

• The affected plants should be removed and destroyed.

• Alternate or collateral hosts harboring the virus have to be removed.

• Raise barrier crops – Sorghum, Maize, Bajra 5-6 rows around the field before planting tomato.

• Spray Imidachloprid 0.05% or any systemic insecticide to control the vector.

Bacterial wilt : Burkholderia solanacearum

Symptom

• This is one of the most serious diseases of tomato crop. Relatively high soil moisture and soil temperature favour disease development.

• Characteristic symptoms of bacterial wilt are the rapid and complete wilting of normal grown up plants.

• Lower leaves may drop before wilting. Pathogen is mostly confined to vascular region; in advantage cases, it may invade the cortex and pith and cause yellowbrown discolouration of tissues.

• Infected plant parts when cut and immersed in clear water, a white streak of bacterial ooze is seen coming out from cut ends.

• The spreads through wounds, soil and implements.

• Avoid damage to seedling while transplanting

• Apply bleaching powder @ 10kg/ha and inrate.

Management

• Crop rotations, viz., cowpea-maize-cabbage, okra-cowpea-maize, maize- cowpea-maize and finger millet-egg plant are reported effective in reducing bacterial wilt of tomato.

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