Diseases Rosa grass

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1. SAM HIGGINBOTTOM UNIVERSITY OF AGRICULTURE, TECHNOLOGY AND SCIENCES, ALLAHABAD DEPARTMENT OF PLANT PATHOLOGY SUBMITTED TO Dr. Mrs. Abhilasha A.Lal Asst. Professor Dept. of Plant Pathology SUBMITTED BY Mr. K. Sachin 16 MSPP 018 Presentation Topic : Diseases of Rosa Grass

2. Diseases of Rosa Grass Scientific Name :- Cymbopogon nardus

3. Introduction Oil obtained from the leaves and stems of different species of  Cymbopogon . The oil is used extensively as a source of perfumery chemicals such as  citronellal , citronellol, and geraniol. These chemicals find extensive use in soap , candles and incense, perfumery, cosmetic, and flavouring industries throughout the world . O il is also a plant-based insect repellent and has been registered for this use in the United States since 1948 .  The United States Environmental Protection Agency considers oil as a  biopesticide with a non-toxic mode of action.

4. Leaf Blight- Curvularia andropogonis The fungus affects the crop in the beginning of monsoon. Small brownish spots appear initially during the month of july,which enlarge into long patches along the tips and marigins of the leaves. In case of serious infections,the entire leaves dry up resulting in considerable decrease in leaf and oil production. Black dots in from of sporulation of the fungus have been seen on dead spots of the leaves.

5. Leaf Blight of Rosa G rass

6. Classification Kingdom : Fungi Division : Eumycota Sub-division : Deuteromycotina Class : Hyphomycetes Order : Moniliales Family : Dematiaceae Genus : Curvularia Species : andropogonis

7. The conidiophores were emerging signally or in groups. They were erect, simple straight or flexuous, sometimes geniculate, 2-17 septate, brown,smooth. The conidia were sometimes straight but more commonly curved, clavate, obconic. The third cell from the base was longer and usually darker than others, middle two cells were brown and dark brown, cells at each end were paler, smooth . Microscopic Character of Pathogen

8. Conidia Sympodial development of Conidia on conidiophore

9. Management Crop rotation. Use of proper sanitation. The disease can be controlled by prophylatic spraying Dithane M-45 or Dithane Z-78@ 20 g/10 litres of water at an interval of 10-15 days during the growing period.

10. Red Leaf Spot : Colletotrichum graminicola Red leaf spot appears in rainy season. Under warm and humid conditions, the disease spreads rapidly and may cause up to 35% reduction in the oil production. The disease perpetuates on left-out stumps and stubbles on the field. The symptom can be seen as small brownish spots, scattered all surface of leaves.

11. Classification Kingdom : Fungi Division : Eumycota Sub-division : Deuteromycotina Class : Coelomycetes Order : Melanconiales Family : Melanconiaceae Genus : Colletotrichum Species : graminicola

12. Microscopic Character of Pathogen The conidiophores are hyaline to brown,septate,branched at base, and smooth. The conidia are hyaline, unicellular ,sickle shaped or cylindrical. The setae are straight,unbranched and tapered toward apex. Setae are brown,smooth,thick-walled and septate .

13. Colletotrichum graminicola

14. Management Two sprays of Bavistin (0.1%) just after the first appearance of disease at an interval of 20 days and three sprays of Dithane M-45(0.3%) at an interval of 10-20 days controls the disease.

15. REFERENCE TOYOZO SATO and HIROTO OHKUBO-Newly Discovered Leaf Blight of Citronella Grass Caused by Curvularia andropogonis in the Philippines. Division of Microbiology, National Institute of Agro-Environmental Sciences ( Tsukuba, Ibaraki, 305 Japan) BOOK- AN INTRODUCTION TO MYCOLOGY R.S.MEHROTRA AND K.R.ANEJA .