Orabanche

symptoms,pathogen and management

1. STUDENT COURSE TEACHER NISHA. S Dr. S. PARTHASARATHY ID. No. 20160210024 Asst . Prof. , (Plant Pathology ) COLLEGE OF AGRICULTURAL TECHNOLOGY Affiliated to Tamil Nadu Agricultural University, Coimbatore Kullapuram , Via Vaigai dam, Theni-625 562 ORABANCHE

2. Orabanche © bioref.lastdragon.org

3. INTRODUCTION It is a total root parasite. Serious phanerogamous parasite of tobacco. It also attacks other crops than tobacco. A single plant carries 10 – 100 flowers and hence, may produce 1,00,000 or more seeds . There are more than 150 species.

4. IMPORTANT SPECIES OF ORABANCHE Orabanche aegyptiaca (Egyptian broomrape) O. ramosa (Branched broomrape) O. crenata (Bean broomrape) O. cernua (Nodding broomrape) O. cumana (Sunflower broomrape) O. minor (Common broomrape )

5. Sunflower parasitized by orabanche ©researchgate.net

6. Orabanche in Legume crops ©link.springer.com

7. Orabanche in Mustard and Tomato ©bjpponline.com

8. PRIMARY HOSTS Tobacco, Tomato, Potato, Pepper, Mustard, Groundnut, Cowpea, Sunflower, Safflower, Cabbage, Cauliflower, Broad bean, Sunhemp , etc.

9. SIGNIFICANCE Orabanche is popularly known as broomrape in English speaking countries, Tokra in North India, Vakumba in Gujarat, Bambaku in Maharashtra, Pokayilaikalan in Tamil Nadu, Bodu or Malle in Andhra Pradesh.

10. It is a flowering parasite on tobacco roots in all tobacco tracts in India. Its is a holoparasite and draws its nourishment from tobacco by means of haustoria attached to the roots of tobacco.

11. ECONOMIC LOSS The loss in the yield and quality of leaf is very much variable from 30 - 70 % in Tamil Nadu and 10 - 50 % in other states.

12. GLOBAL DISTRIBUTION WORLD Mediterranean region Southern, Northern and Eastern Europe Africa New Zealand Australia North, Central and South America

13. INDIA Haryana Punjab Madhya Pradesh Andhra Pradesh Tamil Nadu Karnataka Maharashtra

14. ©plantwise.org

15. SYMPTOMS In the early stages of infection, symptoms of wilting, drooping and ribbing of leaves are observed. These symptoms are the first indication of underground infection of tobacco roots by the parasite.

16. Five to six weeks after planting, young orabanche sprouts emerge from the soil from the base of tobacco plants. Presence of numerous orabanche shoots around the plants in the field is themost important visible symptom.

17. Plants attacked in the early season are generally stunted showing typical wilting of leaves. Plants attacked late in the season do not show visible symptoms of infection but the yield and quality of leaves are reduced .

18. SYMPTOMS ©nofa.in

19. SYMPTOMS ©plantvillge.psu.edu ©forestryimages.org

20. SYSTEMATIC POSITION Kingdom : Plantae Division : Tracheophyta Subdivision : Spermatophytina Class : Magnoliopsida Superorder : Asteranae Order : Lamiales Family : Orabanchaceae Genus : Orabanche L. Species : O. cernua Loefl .

21. CHARACTERS It is an annual, fleshy flower plant, growing up to a height of about 30 cm with cylindrical stem, pale in colour , thickened at base, and covered with scaly leaves that end in spikes. It carries many seeds. The seeds are minute, ovoid and reticulate. They germinate in the presence of the roots of any host.

22. ORABANCHE SEEDS ©idtools.org

23. DISEASE CYCLE The seeds of orabanche remain dormant in the soil for several years, and when tobacco is planted, they are stimulated to germinate by the roots. On germination the plant attaches itself to the roots, establishing a parasitic relationship and then growing rapidly to produce the shoot and flowers.

24. When the seeds are set, they are shed to the ground to become mixed with the soil or at harvest, the shoots are left in the field, after which the seeds are mixed in the soil and the cycle is completed.

25. Life cycle of o rabanche R

26. MODE OF SURVIVAL PRIMARY SPREAD Seeds remain dormant in soil for many years upto 10 – 13 years. SECONDARY SPREAD Agricultural tools used in infested fields.

27. FAVOURABLE CONDITIONS Optimum temperature for germination is 15⁰ - 20⁰C for at least 18 days. It can get fail to parasitize if the soil temperature is too high. Seed germinates in presence of roots of host plant (Root exudates contain growth regulators like IAA, GA₃ and kinetin stimulates germination).

28. MANAGEMENT PREVENTIVE METHODS Use healthy and certified planting materials of improved varieties free from weed seed contamination. Clean farm machinery and equipments to prevent the movement of infested soil to newer areas.

29. Practice deep tillage during summer months. Collect the parasitic weeds prior to flowering and burn. Use well-rotten decomposed green manure, if needed.

30. CULTURAL METHOD Crop rotation with non-host crops like wheat, barley, chickpea, rice etc. Trap and catch crops found effective and may help to reduce seed bank of Orabanche spp.

31. Trap crops - P epper, Sorghum, Cowpea, Sunhemp , Mungbean , Alfalfa, Soybean and Chickpea. Delaying sowing dates - Two weeks after the optimal date of sowing. Increased cropping density may reduce competition.

32. PHYSICAL METHOD Hand pulling before flowering followed by burning. Tillage – deep tillage during summer months. Deep inversion plowing and fire – placement of seeds at 20 cm depth cause little emergence of orabanche and the buried seeds could be brought up by subsequent tillage.

33. Soil solarization – covering moist soil with white or black polythene sheet for a month can increase the soil temperature by almost 10⁰C results in killing orabanche seeds.

34. BIOLOGICAL METHODS Management of orabanche through biological perpetuation of a fly, Phytomyza orabanchia . Inoculation of fungus Fusarium oxysporum f. sp. o rthoceras in the field results in 90% control.

35. CHEMICAL METHODS Soil fumigants like M etham sodium or Dazomet is very effective. Residual soil applied herbicides belonging to dinitroanilines and sulfonyl ureas used for better control. Seed treatment with imidazolinones is found effective.

36. s REFERENCE Singh, R. S., 2009. Plant Diseases. Oxford and IBH Publishing Co. Pvt. Ltd. New Delhi Rangaswami , G and Mahadevan , A. 2014. Diseases of Crop Plants in India. PHI Learning Pvt. Ltd. New Delhi. https://www.itis.gov/servlet/singleRpt/ singleRpt?search_topic = TSN&search _ value=34277#null.