BEAN ANTHRACNOSE

BEAN ANTHRACNOSE AND ITS MANAGEMENT

1. COLLEGE OF AGRICULTURAL TECHNOLOGY (Affiliated to Tamil Nadu Agricultural University, Coimbatore-3) Kullapuram (Po), ViaVaigai Dam, Theni-625 562 BEAN ANTHRACNOSE Submitted by Course teacher RAMYA.V Dr. Parthasarathy.S 2015021106 Assistant Professor (Plant Pathology)

2. HISTORY Anthracnose is mainly a seed borne disease caused by a fungus which has a wide host range on many legume species. In 1921, M. F. Barrus of Cornell University demonstrated that bean anthracnose is seedborne .

3. OCCURENCE AND DISTRIBUTION Anthracnose was first described from plant specimens obtained in Germany in 1875. Later it was spread throughout the world. It has been reported in USA, European countries, Canada, Africa, Uganda, Kenya, Tanzania, Rwanda, Burundi, Ethiopia and D.R. Congo.

4. HOST RANGE Lima bean. Scarlet runner beans. Mung bean. Cow pea and black gram. Broad bean. Soybean and pea.

5. ECONOMIC IMPORTANCE The intensity of this disease ranges from 2 to 100 %. Greatly affect the yield, seed quality and marketability of the crop. The disease causes greater losses in North, Central and South America, Europe, Africa, Australia, Asia , Brazil, Mexico, and Colombia .

6. SYMPTOMS Leaves, stems and pods of bean plants are susceptible to infection. Small reddish-brown, slightly sunken spots form on the pods and rapidly develop into large, dark-sunken lesions.

7. In moist weather, masses of pink spores develops on the lesions. Infection of the leaves causes blackening along the veins particularly on the under surface.

8. www.researchgate.com

9. CONIDIA DEVELOPMENT

10. DISEASE CYCLE

11. SYSTEMATIC POSITION Kingdom : Fungi Phylum : Ascomycota Class : Sordaiomycetes Sub class : Incertae sedis Order : Phyllachorales Family : Phyllachoraceae Genus : Colletotrichum Species : C . lindemuthianum

12. CAUSAL ORGANISM Asexual stage : Colletotrichum lindemuthianum . Sexual stage : Glomerella cingulata . The fungus produced hyaline, single celled, oblong, sickle shaped conidia.

13. MODE OF SPREAD Primary spread : Contaminated seed and crop debris. Secondary spread : Rain splash and wind.

14. FAVOURABLE CONDITIONS Temperature – 13-26° C. Relative Humidity – 92%. Moderate rainfall.

15. CULTURAL MANAGEMENT Removal of infected plant debris. Using diseased free seeds. Crop rotation with non host crops like cereals and solanaceous crops. Giving adequate plant spacing. Avoid overhead irrigation.

16. CHEMICAL MANAGEMENT Seed treatment with Mancozeb @ 3g/kg. Carbendazim foliar spray @ 0.5 kg/ha have been suggested to reduce anthracnose severity and incidence. Difenoconazole 87.5g/ha effectively reduce this disease.

17. PHYSICAL MANAGEMENT Practicing soil solarization for one month before sowing resulted in the reduction of both severity and incidence. Hot water seed treating by soaking at 64 to 74ºC for 15 hrs has been reported to kill the fungus in infested seeds without reducing germination.

18. BIOLOGICAL MANAGEMENT Application of Trichoderma viride as seed dipping and soil drenching was effective against this pathogen. Neem seed extract effectively inhibited both germination of conidia and mycelial growth. Lawsonia inermis seed treatment significantly improved seedling emergence .

19. REFERENCES www.researchgate.com www.sciencedirect.com https://www.gardeningknowhow.com www.moaf.gov.bt