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Similar to Early Blight of Tomato Caused by Alternaria solani
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Early Blight of Tomato Caused by Alternaria solani
- 1. PAT 201-FUNDAMENTALS OF PLANT PATHOLOGY(2+1)
- 2. PGP COLLEGE OF AGRICULTURAL SCIENCE (Affiliated to TamilNadu agricultural university,Coimbatore-3) Senthamangalam Rd, Palani Nagar, Namakkal -637405 SYMPTOMS AND LIFE CYCLE OF Alternaria solani STUDENT COURSE TEACHER Ms.Malathi.P Mr.M.Krishnamoorthi ID.No.2019024051 Assistant professor PGP college of agricultural sciences Course Associate Ms.T.Suganya
- 3. INTRODUCTION • Alternaria solani • Causative agents - early blight in solanum species • The pathogen produces distinctive “bullseye” patterned leaf spots and can also cause stem lesions and fruit rot on tomato and tuber blight on potato.
- 4. Alternaria • It is multicellular pigmented spores are produced in chains or in branching fashion
- 8. Early blight (Alternaria solani) on Tomato (Lycopersicon esculentum)
- 9. SYMPTOMS • Foliar symptoms of Alternaria solani - oldest leaves and smart as small lesions that are brown to black on color. • These leaf spots - concentric rings • Both the area around the leaf spot and the entire leaf may become yellow or chlorotic.
- 15. • Under favorable conditions (e.g., warm weather with short or abundant dews) - significant defoliation of lower leaves , leading to sunscald of the fruit. • Stem lesions - dark, slightly sunken and concentric in shape. • Fruits spots are similar leaves – brown with dark concentric circes. • Mature lesions - a black, velvety mass of fungal spores
- 17. SYSTEMATIC CLASSIFICATION / TAXONOMIC POSITION • Domain : Eukarya • Kingdom : Fungi • Phylum : Ascomycota • Class : Dothediomycetes • Order : Pleosporales • Family : Pleosporaceae • Genus : Alternaria • Species : solani
- 18. PATHOGENIC CHARACTER • The mycelium - septate and branched, hyaline in the beginning and later becomes darker in color • The conidia - 12-20 × 120-296 µm • Conidia - 9-11 transverse septa (cross walls). • Conidiophores are short and produces an obclavate of muriform shaped conidia with horizontal and vertical septation and it is pointed at distal end.
- 19. MYCELLIUM
- 20. MODE OF REPRODUCTION • Alternarias - no sexual or perfect stage. • The multiply asexually - sporulation. • asexual spores - exogenously are the conidia. • The conidia are produced at the tips of ordinary hyphae which are comparatively short and dark coloured .
- 23. • The conidia - large, dark coloured, several celled and beaked. • The number of cells - 8-14 or even more . • The component cells occur packed in muniform, conidal masses. • The septa dividing the spore into cell and both transverse and vertical and their number is not fixed.
- 25. DISEASE CYCLE
- 28. • The fungus can survive in soil and in infested crop and weed residues. • It may be seed-borne and carried by wind, water, insects, workers and farm equipment. • The spores that land on tomato plants will germinate and infect the leaves when they are wet.
- 29. • Spores enter - leaf, steam or fruit. • The fungus more active - mild to warm temperature and wet weather. • The disease worse during - rainy seasons. • Early blight is most severe on plants stressed by a heavy fruit load, nematode attack, or low nitrogen fertility.
- 31. FAVOURABLE WEATHER CONDITIONS • Maximum temperature of 15-29°C • Minimum temperature of 4-12°C • Average relative humidity >60% • RH I (Morning)>76% • RH II (Afternoon)>25%
- 32. MANAGEMENT ASPECTS CULTURAL CONTROL Clear infected debris from field to reduce inoculum from the next year. Rotate to a non-solanaceous crop for atleast three years. Removal and destruction of infected plant debris should be done because the spores lying in the soil are the primary source of infection.
- 33. CHEMICAL CONTROL Very early spraying with zineb or captan 0.2% and repeating it for every 15-20 days gives effective control.
- 34. CONCLUSION • Moreover to determine the levels of genetic varation of alternaria spp. Is important to know the population structure and migration structure of the pathogen.
- 35. • Early blight of tomato,dark black and slightly sunken, sunscald of fruit. • Picture courtesy : J.B.Jones , T.A.Zitter , M.T.Momol, and S.A.Miller , Tomato diseases.
- 36. • Conidia of alternaria solani , blue brightfield conidia, fungus infection. • Picture courtesy : nature picture library conidia