Blast and leaf spot of finger millet (RAGI)

BLAST AND LEAF SPOT OF FINGER MILLET or RAGI or MANDUWA or NAACHNI, प्राचीन काल से ही हमारे देश में पारम्परिक मोटे अनाज जैसे कि ज्वार, जौं, मक्का आदि का सेवन किया जाता रहा है। इन्हीं मोटे अनाजों में से एक है रागी। यह अनाज सेहत के लिए बहुत ही लाभकारी है

1. Dinesh K. Pancheshwar Assistant Professor Department of Plant Pathology College of Agriculture, JNKVV, Balaghat

2. Blast of Finger millet ( Ragi ) Caused by : Pyricularia oryzae

3. Symptom Infects at any stage of the growth from the seedling to the grain formation stage. The infection appears in the nursery from second week of germination and spread quickly to entire nursery as well as to main field. Small brown circular to elongated spots appear on leaves which eventually develop into large elongated spindle shaped areas in the seedling stage. The spindle shaped spots appear on leaves in the main field. Several spots coalesce and cause drying of foliage

4. Maximum damage is caused by the neck blast . The neck region turns black and shrinks. Infection occurs at the basal portions of the panicle branches including the fingers and the ear head breaks away from the stalk. The affected portions turn brown and ears become chaffy and only few shriveled grains are formed. Some of the fingers are also affected causing finger blast. The fingers become chaffy and only few shriveled grains are formed.

5. INFECTED PLANT BLAST ON LEAF FINGER BLAST

6. Mycelium is intra and inter-cellular. Numerous conidiophores and conidia are produced in the central portion of the spindle shaped spots under humid conditions. As a result, the spot assumes a smoky appearance . Conidiophores emerge through the stomata or through the epidermal cells are simple septate and dark coloured. Etiology of the Pathogen

7. Conidia are borne at the tip of the conidiophores. Conidia are pyriform , three celled, hyaline, two septate . Conidia germinate with germ tubes which infect the leaf wither through epidermal cells or stomata.

8. Management Treat the seed with  Pseudomonas fluorescens  @ 6g/Kg seed and spray the extracts of  Prosopis   juliflora  leaf extract (10%),  Ipomoea   carnea  leaf extract (10 %) or Seed treatment with carbendazim @ 1 gm/Kg of seed. Foliar spray with premixture fungicide ( Carbendazim+Mancozeb ) @ 0.2% concentration at 50% earhead emergence followed by a second spray with   Pseudomonas   fluorescens  (Pf1) at 2g/lit of water 10 days later.

9. leaf spot of Finger millet   Caused by : Helminthosporium nodulosum

10. Symptom The pathogen affects both seedling and the adult plants. Minute, oval, light brown lesions on the young leaves and become dark brown. Several such lesions coalesce to form large patches of infection on the leaf blade. The affected blades wither prematurely and the seedlings may be killed. Linear oblong and dark brown spots appear on the leaves of grown up plants. The leaves give blightening appearance .

11. Prominent brown to dark brown discoloration in the neck region  and followed by weakening of neck tissue that causes it to break and the ears hanging down from the plant. While nursery infection causes heavy damage due to the seedling blight, neck infection causes heavy chaffiness and severe loss in grain yield. It is seed-borne and primary infection is through seed. Secondary infection through air borne conidia and stubbles.

12. INFECTED PLANT LEAF SPOT BLIGHTED SYMPTOMS

13. Etiology of the Pathogen The mycelium is intra and inter-cellular, septate and light brown in colour. Conidia are erect or curved septate and dark brown. They are borne at the tip of  conidiophores. Conidiophores are thick walled cylindrical or obcavate straight or curved and light green in color and 3-10 septate . The spores germinate either through the stomata or epidermal cells. 11 spores may be formed in one conidiophore .

14. Management Treat the seeds with Captan or Thiram @ 4g/Kg seed. Spray Mancozeb @ 1.25Kg/ha or spray 1% Bordeaux mixture or Copper oxychloride or Dithane Z-78 (2g/lit. water ).

15. THANKS Dr. D. K. PANCHESHWAR ASSISTANT PROFESSOR PLANT PATHOLOGY COLLEGE OF AGRICULTURE JNKVV, MURJHAD FARM BALAGHAT