nematodes nematodes feed on insider part of plant roots and form galls. root-knot nematodes cause up...

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