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Nematodes
• Nematodes feed on insider part of plant roots and form galls.
• Root-knot nematodes cause up to 30% losses in tomato crop yield.
Root Galls formed by Root-knot Nematodes
• Field sanitation and crop rotation
with non-Solanaceous crops can
reduce survival of nematodes.
• Solarization of growth media/soil for
4 to 8 weeks before use or
application of carbofuran or oxamyl
can reduce infestation of
nematodes.
• Addition of organic matter to soil
reduces nematode population.
Diseases
Fungi and bacteria cause foliar, fruit, stem or root diseases while virus
infection leads to stunted growth and reduced fruits production.
Bacterial Wilt:
•Ralstonia solanacearum causes
bacterial wilt disease in humid
climate with higher temperature.
•Bacteria enter roots of seedlings
through injuries and wounds and
spread through irrigation water,
soil movement or transplantation
of infected seedlings.Affected Plants and Section of Stem
Bacterial Wilt
• Wilting of terminal leaves, followed by a sudden permanent
wilting of seedlings in 2-3 days without yellowing of leaves.
• Adventitious roots develop on main stems. The vascular system
of infected plants appears light brown in transverse section
Management of Disease:
• Avoid growing tomato nursery in infected fields. Eradicate weed
hosts, remove wilted plants, root debris and burn them.
• Disinfest tools used in infected field by bleach or flame. Sterilize
the soil with fumigants like methyl bromide.
Septoria Leaf Spot
Septoria lycopersici causes small and water-soaked leaf spots in
tomato which are later become circular about 3 mm in diameter.
Lesions gradually develop grayish white centers with dark edges is a
distinctive symptom of Septoria leaf spot disease.
Septoria Leaf Spot of Tomato
Management of Disease:
• Crop rotation in nursery site.
•Use of copper, potassium
bicarbonate based fungicides or
bio-fungicide like QST 713 strain of
Bacillus substilis .
Early Blight of Tomato
Alternaria solani fungus causes early blight disease resulting in to
shedding of lower leaves along with brown to black spots with dark
edges on lower leaves. The spots merge to form irregular blotches.
Dark, concentric rings visible on the blotches.
Disease Management:
•Use disease resistant varieties and disease free seeds for nursery.
•Optimum nutrition should be provided to nursery. Crop residue
must be removed and destroyed.
•Copper fungicide like Azoxystrobin, pyraclostrobin, chlorothalonil
are used for spraying.
Early Blight of Tomato
Early blight disease symptoms on leaves Rotting of Tomato fruits
• Tomato spotted wilt virus (TSWV) disease caused due to virus
transmitted by insects like Thrips, where the growing tips of the
plant die off.
• Young leaves of infected plants turn bronze colored and develop
numerous small dark spots and shiny, dark brown streaks
appear on infected stems and petioles.
Disease Management:
• Monitor, manage and reduce thrips population in infected field by
using yellow sticky cards. Infected plants must be destroyed.
• Use TSWV resistant tomato varieties like, Amelia, BHN 601,
BHN 640, Crista, Nico, Red Defender, Quincy and Talladega.
Tomato Spotted Wilt virus
Tomato Plants infected by Tomato Spotted Wilt Virus
Tomato Spotted Wilt virus