CITRUS ANTHRACNOSE

CITRUS ANTHRACNOSE AND ITS MANAGEMENT

1. CITRUS ANTHRACNOSE SUBMITTED BY, COURSE TEACHER DEEPTHI.S, Dr. PARTHASARATHY.S, 2015021027. Asst.Prof .,(Plant Pathology)

2. CAUSAL ORGANISM Anamorph stage (asexual stage) Colletotrichum gloeosporioides Teleomorph (sexual stage) Glomerella cingulata

3. SIGNIFICANCE Post harvest loses in citrus in several tropical countries ranges from 15%. In China and Brazil it recorded first – Sao Paulo state (Brazil). The incidence of this disease reach 100% in fruit under wet conditions.

4. DISTRIBUTION World Pakistan, Brazil, China, India and also worldwide in distribution. India Himachal Pradesh, Tamil Nadu, Karnataka, Andhra Pradesh etc.,

5. SYMPTOMS ON LEAVES Common symptoms are a more or less circular, flat area, light tan in color with a prominent purple margin that at a later phase of infection will show the fruiting bodies of the fungus (tiny dispersed black flecks).

6. SYMPTOMS ON LEAVES

7. SYMPTOMS ON FLOWERS Infections on the flowers ( form clusters) start as small black or dark- brown spots. These can enlarge, coalesce and kill the flowers. They starts disintegration.

8. SYMPTOMS ON FLOWERS

9. SYMPTOMS ON FRUITS Fruit - anthracnose usually only occurs on fruit that have been injured by other agents . The  lesions are brown to black spots of 1.5 mm or greater diameter. The decay is usually firm and dry but if deep enough can soften the fruit. 

10. SYMPTOMS ON FRUITS

11. PATHOGEN CHARACTERS Conidiophore is simple, hyaline, branched hypha on which conidia are produced. Conidia is thin walled with large number of oil globules.

12. CONIDIA OF Colletotrichum gloeosporioides

13. DISEASE CYCLE OF Colletotrichum gloeosporioides

14. Dissemination Conidia are dispersed passively by splashing of rain or irrigation water. Symptoms and disease development Black , sunken, rapidly expanding lesions develop in fruiting bodies ( Acervuli ). Pathogen survival The pathogen survives between seasons on infected and defoliated branch terminals and mature leaves.

15. MODE OF INFECTION Primary spread Air borne conidia and innoculums present in the seeds are source of primary infection. Secondary spread Spores spread through rain splashes and irrigation water and also by infected debris.

16. FAVOURABLE CONDITIONS High humidity Temperature of 24°C – 28°C. Frequent rains. Moist conditions favours the development of disease (October to November ).

17. INTEGARATED DISEASE MANAGEMENT Pruning of infected leaves, twigs and fruits. Fruit bagging at fruit set stage ( late O ct – early Nov ) Spray twice with Carbendazim ( 0.1%) at 15 days interval during flowering to control blossom infection.

18. Spraying of Mancozeb 2 g/lit Thiophanate methyl 1 g/lit or chlorothalonil 2 g/lit 3 times at 15 days interval. Spray copper fungicides (0.3%) for the control of foliar infection. Post harvest treatment with Benzimidazole may reduce fruit loss.

19. REFERENCES Saha.L.R , ’Handbook of plant Diseases’ 2002, Kalyani publishers, New Delhi. Thind.T.S , “Disease of fruits and vegetables and their management”, Kalyani publishers second edition 2016,New Delhi. https://www.plantnatural.com>anthracnose idtools.org>citrus>diseases>factsheet