coconut stem bleeding

PAT 401

1. COLLEGE OF AGRICULTURAL TECHNOLOGY (Affiliated to Tamil Nadu Agricultural University, Coimbatore-3) Kullapuram (Po), ViaVaigai Dam, Theni-625 562 COCONUT STEM BLEEDING STUDENT Miss Yenugula Pravallika ID. No. 2015021141 COURSE TEACHER Dr. PARTHASARATHY S Asst. Professor (Plant Pathology)

2. COCONUT STEM BLEEDING Causal Organisms : Thielaviopis punctulata Ceratocystis paradoxa (perfect stage) Thielaviopsis paradoxa (imperfect stage)

3. HISTORY The disease was first reported from Srilanka and serious infection lead to yield reduction ( Nambier & Sastry , 1988). In Indonesia stem bleeding causes severe damage PB121 hybrid and affects yield ( Kartika et al.,1984 ).

4. HOSTS All palm species are considered potential hosts of  Thielaviopsis paradoxa .   The only known hosts of  Thielaviopsis punctulata  are  Cocos nucifera  and  Phoenix dactylifera .

5. DISTRIBUTION Thielaviopsis paradoxa   has a worldwide distribution. Thielaviopsis punctulata  appears to be limited to Kuwait, Mexico, South Africa and the USA. In India, most commonly seen in north parts of Kerala .

6. SYMPTOMS Stem Bleeding is characterized by the exudation of a dark reddish brown liquid from the longitudinal cracks in the bark and wounds on the stem. The lesions spread upward as the disease progresses. The liquid oozing out dries up and turns black. The tissues below the lesions become rotten and turn yellow first and later black.

7. In advanced cases, the inner portions of affected trunks are hollow due to decay of inner tissues. As a result of extensive damage in the stem tissue, the outer whorl of the leaves turn yellow, dry and shed prematurely. The production of bunches is affected adversely. Nut fall is also noticed.

8. Figure 1: Figure 2: http://agritech.tnau.ac.in/crop_protection/images/coconut_diseases/N6.1.jpg http://agritech.tnau.ac.in/crop_protection/images/coconut_diseases/N6.2.jpg

9. Figure 3: http://agritech.tnau.ac.in/crop_protection/images/coconut_diseases/N6.3.jpg

10. SCIENTIFIC CLASSIFICATION KINGDOM : Fungi PHYLUM : Ascomycota CLASS : Pezizomycotina SUB CLASS: Sordariomycetes ORDER : Microascales FAMILY : Ceratocystidaceae GENUS : Thielaviopsis SPEICES : T. paradoxa , T . punctulata

11. Pathogen : Fungus produces macro conidia and micro conidia. Macro conidia are spherical and dark green produced on conidiophores singly or in chains. Micro conidia are hyaline and cylindrical form.

12. Figure 4: https://en.wikipedia.org/wiki/File:Thielaviopsis_basicola_1.JPG

13. Favourable conditions: The progress of the disease is faster during July to November. Growth of cracks on the trunk followed by heavy rains is the favourable condition to spread. Poor maintenance of garden.

14. Mode of Spread and Survival: The fungus is air borne. Fungus survives in plant debris. Irrigation and rain water also helps in disease spread. Beetles which feed on the diseased plants also help in transmission.

15. Management : Physical: Destroy the chiseled materials by burning. Avoid any mechanical injury to trunk. Provide adequate irrigation during summer and drainage during rainy season along with recommended fertilizer.

16. Chemical: Chisel out completely the affected tissues and paint the wound with trifloxystrobin 0.5% or Bordeaux paste 10%. Apply coal tar after 1-2 days on the treated portion. Root feed with trifloxystrobin 0.5% in water , thrice a year during April-May, September-October and January-February to prevent further spread of lesions.

17. Biological: Along with FYM 50kg , apply neem cake 5kg containing the antagonistic fungi,  Trichoderma at   200g / palm/ year culture to the basin during September.

18. References: https://en.wikipedia.org/wiki/Thielaviopsis http://www.scielo.br/pdf/tpp/v34n3/v34n3a07.pdf http://agritech.tnau.ac.in/crop_protection/coconut_ diseases_4.html