Pat 201 - Mango anthracnose - colletotrichum mangiferae

Symptoms, Taxonomic classification and life cycle of
Colletotrichum mangiferae

Anthracnose is presently recognized as the most important field and post-harvest disease of mango worldwide (Ploetz and Prakash, 1997). It is the major disease limiting fruit production in all countries where mangoes are grown, especially where high humidity prevails during the cropping season. The post-harvest phase is the most damaging and economically significant phase of the disease worldwide. It directly affects the marketable fruit rendering it worthless.
This phase is directly linked to the field phase where initial infection usually starts on young twigs and leaves and spreads to the flowers, causing blossom blight and destroying the inflorescences and even preventing fruit set.
Mango anthracnose is caused by Glomerella cingulata (Stoneman) Spauld. and H. Schrenk (anamorph: Colletotrichum gloeosporoides (Penz.) Penz. var. minor J.H. Simmonds (Fitzel and Peak, 1984) and C. acutatum J.H. Simmonds (Freeman et al., 1998).
The pathogen also causes blossom blight, leaf blight and in some severe cases, tree dieback (Ploetz, 1994; Ploetz et al., 1996). In Australia and India, C. acutatum (teleomorph: Glomerella acutata) has been reported to also play a minor role in causing the disease (Fitzell, 1979; Prakash, 1990).

1. Symptoms, Taxonomic classification and life cycle of Colletotrichum mangiferae Submitted by J. Jeevambigai (2019024036) Course teacher Mr. M.krishnamoorthi Assistant professor Plant pathology PGP College of Agricultural sciences (Affiliated to Tamil Nadu Agricultural university) Palani nagar,Vettambadi,Namakkal 637405

2. Introduction Post harvest losses of mango in several tropical countries. Common name :Mango anthracnose. Dry condition -15% Loss Wet condition -70%loss India &china –15%-25%yield loss In wet condition 100%reached this disease .

3. Varities None of the cultivars of mango was resistant to anthracnose disease . Highly susceptible varieties Amrapali Totapuri Safeda Mallika Moderately susceptible Alphonso Baramasi Samer Bahist Chausa Sindhuri .

4. Casual organism Anamorph stage (Asexual stage ) Colletotrichum gloeosporioides ( penz &sac ) Teleomorph (sexual stage ) Glomerella cingulata .

5. SYMPTOMS The disease affect the leaves, twigs, petiole, flower clusters and fruits. Leaves Small spots, angular, depressed brown to black colour spots with shot hole symptoms. Lesions started at small than it can enlarge to form extensive death .

6. Symptoms on leaves

7. Symptoms on stems &branches Die back symptoms on young twigs ( It affect Tip to downward position ). black colour lesions also present on the twigs .

8. Panicles Small black to dark brown spots, which can enlarge &kill the flowers before fruiting.

9. Sunken , prominent, dark brown to black decay spots before or after picking. Pitting symptoms and also tear stain effect .

10. Linear necrotic regions show alligator skin effect associated with cracking on epidermis .

11. Systematic position Domain : Eukarya Kingdom :Fungi Phylum :Ascomycota Class:Sordariomycetes Order:Glomerellales Family:Glomerellaceae Genus: colletotrichum Spieces : G loeosporioides

12. Pathogenic characters Conideospore is simple , branded hypae on which conidia are produced. Conidia is an asexual non motail fungi spore that develop externally from the cell that formed it.

13. Asexual Reproduction

14. Mode of reproduction Asexual reproduction Conideospores are hyaline , short, simple and aseptate . Conidia-hyaline, single celled, cylindrical – two oil globules –produced singly at the apex of the conidiophore. Setae are common in acervuli on twigs but absent on fruits . Conidia remain embedded in a viscid fluid which swells in moist condition, rupture the epidermis &expose the conidial masses as pink masses .

15. Sexual Reproduction Teleomorph

16. Sexual reproduction The anormph is reproduced more frequently during the growing season &the sexual reproduction occurs mostly in debris . The perthecium contains hyaline, filliform paraphysis and asci . Asci are clavate, eight spored . Ascosposres are hyaline single celled, allantoids (banana shaped ) or elliptical shaped , ejected from the tip of the ascus and are difficult to distinguish from conidia .

17. Life cycle of colletotrichum gloeosporioides

18. Life cycle of colletotrichum gloeosporioides Asexual reproduction Germination of conidia &formation of mycelium . Infection &symptom production. Formation of Acervulus, conidiophore with conidia . Sexual reproduction Formation of perithecium, ascus and ascospores. Ascus releasing the ascospores.

19. Favarouble condition High Humidity Temperature 24°C-32°C. Frequent rain. Moist condition is favourable for the development of Diseas e October to November .

20. Management aspects Site selection Cultivar selection Cultural practises in field (sanitation, plant spacing, inter cropping, etc..) Fungicides sprays in the field Post harvest treatment (physical, chemical).

21. Chemical control Spray p.fluroscens (FP7) at 3weeks interval commencing from October at 5g 5-7times at flower branches Spray twice with carbendiazim 0.1% at 15days during flowering to control blossom infections. Spraying of Mancozeb 2g/lit Thiophanate methyl 1g/lit or chlorothalonil 2g/lit3times at 15days interval .

22. Cont… Spray copper fungicides 0.3% for the control of Foliar infection. Before storage, treat with hot water 50-55°c for 15minutes or dip in benomyl solution (500ppm ) or Thiobendazole (1000ppm ) for 5minutes .

23. Photo courtesy Madhu   Kamle et al Amy grand Helen Tsatsia Charles A. Onyean