Citrus canker ppt
- 2. Contents • What is the disease? • Symptoms • Causal organism • Disease Cycle • Control measures
- 3. What is the disease? • A disease is a particular abnormal condition that aff ects part or all of an organism and that consists of a disorder of a structure or function. • A condition of the living animal or plant body or of one of its parts that impairs normal functioning and is typically manifested by distinguishing sings and sy mptoms.
- 4. Symptoms • It is the most serious bac terial disease. • The disease affects the le aves, twigs, thorns and frui ts. • All green parts and matu ring fruits become more or less covered with brown sc abby spots surrounded by dark-brown glossy margins.
- 5. • The lesions appear as s mall yellowish spot, which enlarge to a diameter of 3 or 4 mm. and become rais ed and rough or spongy an d turn brown. • The market value of the fruits is reduced, because of the appearance of scabb y lesions.
- 6. Causal organism • Citrus canker is caused by Xanthomonas citri. • It is a gram negative, monotrichous, capsulated bac illus which is strictly aerobic in nature. • It is 1.5-3 micrometer in length and 0.5-1.5 microm eter in breadth. • The bacteria does not produce endospores and can not reduce nitrates.
- 7. • It is aerobic. • Colonies on beef agar are circular, straw yellow to a mber yellow. • Nitrates are not reduced. • The bacterium enters through stomata and wounds.
- 8. • The disease is favoured by mild temprature and we t weather. • From the cankers, disease spreads by driving rains and insects. • Man is also an important agent of dissemination th rough infected nursery stock.
- 9. Classification of pathogen Kingdom: Bacteria Phylum: Proteobacteria Class: Gammaproteobacteria Order: Xanthomonadales Family: Xanthomonadaceae Genus: Xanthomonas Species: Citri
- 10. Disease Cycle
- 11. Control measures • Various methods are adopted for the control of citr us canker. • Some important measures are as follow : 1) Complete destruction of diseased plant by burning them. 2) Use of disease free nursery stock for planting.
- 12. 3)Spraying the plant before planting with 1% Bordea ux mixture. 4)Antibiotic spray with streptomycin, phytomycin. 5)Spraying leaves with neem-cake (160 lbs/acre). 6)Disease resistant varieties.
- 13. References • The DBS Handbook of Botany by : Lalit Kum ar Dwivedi. • Fungi and Allied organisms by : P.D. Sharma •Plant pathology by : B.P.Pandey https://en.m.wikipedia.org https://www.slideshare.net