Early blight of tomato

Causal organism, Symptoms, Epidemiology, Etiology, Life cycle and Management of Early Blight of tomato

1. Diseases of Vegetable and Spice Crops
(PTH 527)
Early Blight of
Tomato
Pansuriya Dhaval

2. Early blight of tomato
Causal organism: Alternaria solani
Symptoms
Symptomsgenerallyoccuronalltheplantpartleaves,stem,fruit.
FoliarsymptomsofA.solanigenerallyoccuronoldestleavesandstartas
smallbrowntoblacklesions,enlargeinacharacteristicallyconcentric
ringsit'ssurroundedbyyellowincolour.
Stemlesionsdark,slightlysunkenandconcentricinshape.
Fruitsportsbrownwithdarkconcentriccircles,maturelesionstypically
coveredbyblackvelvetymassoffungalspore.

3. Target-like Spot
on leaves
Black sunken lesions
on stems
Black sunken areas
on fruit

4. Epidemiology
Dry and warm weather with temperature 25 -30°C of and high relative humidity.
Generally infection during rainy season.
Etiology
Myceliumishyaline,septet,branchedand
laterbecomedarkincolour.
Conidiophoreareshortandproduced
muriformshapedconidia.
Conidiaare12-20x120-296µminsize.
Conidiaaresinglyorinchainoftwowith9-
11transverseptation.

5. Disease Cycle

6. Management
Long crop rotation.
Removed weeds and volunteer solanaceouscrop plants.
Remove and destroy crop residue at the end of the season.
Use pathogen free seed and transplant.
Maintain plant vigorthrough proper fertilization and adequate irrigation.
Use resistant varieties Juliet F1, Old brooks, CLN-2071-C, CLN-2070-A
and BSS-174.
Spraying with Copper oxychloride50% WP@25gm/10 lit. of water or
captan50% WP @ 25gm/10 lit. of water.