Nematodes

1. Nematodes • Nematodes feed on insider part of plant roots and form galls. • Root-knot nematodes cause up to 30% losses in tomato crop yield. • 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. Root Galls formed by Root-knot Nematodes

2. Diseases Fungi and bacteria cause foliar, fruit, stem or root diseases while virus infection leads to stunted growth and reduced fruits production. • Bacterial Wilt: • Ralstoniasolanacearumcauses 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

3. 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.

4. 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. • 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 . Septoria Leaf Spot of Tomato

5. Early Blight of Tomato Alternariasolani 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.

6. Early Blight of Tomato Early blight disease symptoms on leaves Rotting of Tomato fruits

7. Tomato Spotted Wilt virus • 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.

8. Tomato Spotted Wilt virus Tomato Plants infected by Tomato Spotted Wilt Virus