Diseases of turmeric

Diseases of turmeric

1. COLLEGE OF AGRICULTURAL TECHNOLOGY (Affiliated to Tamil Nadu Agricultural University, Coimbatore-3) Kullapuram (Po), ViaVaigai Dam, Theni-625 562 DISEASES OF TURMERIC STUDENT COURSE TEACHER Miss. Suraparaju deepthi Dr. PARTHASARATHY S ID NO : 2015021129 Asst.professor ( Plant pathology)

2. Major diseases Diseases Causal organism Leaf spot Colletotrichum capsici Leaf botch Taphrina maculans Rhizome rot Pythium aphanidermatum

3. Occurance Leaf spot disease of turmeric caused by C.capsici was reported for the first time from coimbatore district by Mc Rae in 1917. Disease is a soil borne noticed on the leaves from july to october . In Gujarat, leaf spot of turmeric caused by C.gloeosporioides was first reported by Patel et al. (2005).

4. Leaf spot PATHOGEN Causal organism : Colletotrichum capsici Distribution It is widely distributed in Asia, Africa, Australia, North and Central America.

5. Losses Leaf spot is the most important disease of turmeric resulting in losses of 25.83 – 62.12 % fresh weight and 42 – 62 % dry weight of rhizomes. The incidence of turmeric leaf spot caused by C.capsici reported 50 % yield loss.

6. Conidiophores are hyaline, cylindrical, unicellular or septate . The sexual ascomycete form is rarely found in nature. Pathogen

7. Favourable conditions High soil moisture, temperature of about 25°C and leaf wetness are most important environmental conditions to favour the disease. It requires relative humidity of 80 % temperatures of 21°C – 23°C to favour primary infection. This disease usually appears in October and November.

8. Mode of spread This is a soil borne disease and survives in plant debris upto one year. Primary spread Through rain splash and irrigation water. Secondary spread Through infected soil, farm tools and shoes.

9. Taxonomic position Kingdom : Fungi Phylum : Ascomycota Class : Sordariomycetes Order : Incertaesedis Family : Glomerellaceae Genus : Colletotrichum Species : C. capsici

10. Symptoms In affected leaves, elliptical or oblong spots with yellow halo are seen. The centre of spots are greyish white and then with numerous black dots in centre. As the disease advances, the leaves dry up and give a scorched appearance.

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12. Management Field sanitation Spray with Mancozeb 0.25 % or copper oxy chloride 0.25 % immediately after the appearance of symptom and at 15 days interval.

13. Leaf blotch Causal organism Taphrina maculans Distribution It has been reported in Bangladesh and India.

14. Occurance Leaf blotch disease was reported for the first time(Butler1911) from Gujarat, Saharanpur and Rangapur (East Pakistan ). Later, it was observed from all turmeric growing regions of the country. Severe outbreak of this disease was reported during 1955-57 from Rayalaseema area of Andhra pradesh .

15. Taxonomic position Kingdom : Fungi Phylum : Ascomycota Class : Taphrinomycetes Order : Taphrinales Family : Taphrinaceae Genus : Taphrina Species : T. maculans

16. Pathogen It is a fungal plant pathogen . The fungus was first described scientifically by Irish mycologist Edwin John Butler in 1911.

17. Mode of spread Soil and seed borne and survive in soil on infected plant debris. Favourable conditions High soil moisture, temperature 25°C and leaf wetness.

18. Symptoms The attacked leaf presents a reddish brown appearance instead of the normal green colour . The disease is characterized by the appearance of several spots on both the surface of leaves and more numerous on upper surface. These spots coalesce to form irregular bigger patches.

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20. Management Field sanitation Spray with Mancozeb 0.25 % or copper oxy chloride 0.25 % immediately after the appearance of symptom and at 15 days interval.

21. Rhizome rot Causal organism : Pythium aphanidermatum Distribution It is distributed world wide.

22. Scientific classification Phylum : Heterokontophyta Class : Oomycota Order : Peronosporales Family : Pythiaceae Genus : Pythium Species : P. aphanidermatum

23. Favourable conditions Moist conditions facilitate the most rapid spread of the disease. The pathogen can cause disease in cool temperatures but idea conditions are in between 86°F and 95°F. Excessive nitrogen fertilization will also increase the chance of infection.

24. Pathogen It is a soilborne plant pathogen belonging to the fungus-like organism oomycetes . Asexual P.aphanidermatum produces terminal, inflated, lobate sporangia with hyphal swellings. Sporangia give rise to bifagellate zoospores. Sexual It is homothallic producing both male and female gametangia . Oogonia are terminal, globose, smooth. Antheridia are mostly intercalary, sometimes terminal, broadly sac- shaped.

25. Mode of spread Primary spread It mainly spreads via motile zoospores, because zoospores need to swim in order to infect the host. Secondary spread Moist conditions facilitate the most rapid spread of the disease.

26. Symptoms In infected pants, basal portion of the shoots appear watery and soft. The root system is very much reduced. The leaves exhibit gradual drying along the margin. Infected rhizomes soft, rotted, colour changes into different shades of brown.

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28. Management Use disease free planting material. Providing good drainage facilities. Rhizome dip in copper oxy chloride or zineb (0.3%) for 30 minutes before planting Soil drenching with copper oxy chloride (0.25%) in and around affected plants Soil application of  Pseudomonas fluorescens  talc formulation (2.5 kg/ha)

29. Other minor diseases Leaf blight ( Corticum sasakii ) Dry rot ( Rhizoctonia bataticola ) Brown rot ( Pratyenchus sp and Fusarium sp).

30. References http://agritech.tnau.ac.in Singh.V.B , Kriti singh - Spices, New age International publisher. Saha.L.R , Handbook of plant diseases, 2002, Kalyani publishers, New Delhi.