Crop disease and their managemen basic

Defination, Objective, principle, history of Crop disease and their management

1. Crop Disease and their management Presented by – Animesh raj.

2. P l an t P at h ol o gy ( Ph y t o p a t h o lo g y ) : - The term plant pathology is derived from three Greek words: - Phyton + Pathos + logos Plant + suffering/diseases + study/knowledge Definition : - “Plant Pathology is that branch of agricultural, botanical or biological science which deals with the study of the causes, etiology (infected form), resulting losses, management and control of plant diseases.”

3. Objectives Of Plant Pathology To study the biotic, abiotic and environmental causes of plant diseases. To study the mechanism of disease development. To study the interaction between plant and pathogen. To develop the methods of plant disease management or control .

4. H i s to r i c a l D eve l o p m en t Of Plant Pathology Theophrustus (370-286 BC ): - He write a book entitled “Inquiry into Plants” . He wrote the observations regarding diseases in this book. Julius Kuhn (1858): - Write first book of Plant Pathology entitled . “ Disease of Cultivated Crops Their Causes And Their Control” T.J. Burril ( 1878 ): – Reported first plant disease caused by bacteria entitled “Fire Blight of Peach and Apple” Prof. Millaradet (1885 ): - Prepare first time “ Bordeaux Mixture ” Mayer (1886 ): – Worked on Tobacco Mosaic caused by Virus.

5. Plant Pathologist Of India E . J. Butler (1901-1920 ): – First plant pathologist in India . He wrote a book -“Fungi and disease in plant”. He is known - “Father of Plant Pathology in India” D . D. Conninghum & A. Barclay: – Start study and identification of fungi. J . F. Dastur (1886-1971 ): - First Indian Plant Pathologist. He worked on Caster and Potato diseases caused by Phytophthora.

6. Impact Of Plant Disease Losses caused by different pest in crops PEST LOSS (%) Weeds 33 Diseases 26 Insects 20 Storage pests 7 Rodents 6 Other’s 8 Total = 100%

7. Assessment of losses At least 10-30% of global food production Representing a threat to food security According to the report (2004) it is estimated that annual losses by disease cost US$ 220 billion.

8. Pathogen: - “ Any entity which can insite the disease is known as pathogen ” T ypes of pathogenic microorganisms: - (A). Biotic pathogens or Animate Causes: - Fungi Bacteria Phytoplasma or Spiro plasma Nematode (Worm) Algae Protozoa Parasitic Plants

9. (B ). Mesobiotic causes: - Virus Viroid Prion ( C ) . A bio t i c o r I n a n i m at e ca u se s: - Adverse climatic conditions: - Light, Temperature, Humidity, Rain, Hail, Frost, Strom. b) Adverse soil conditions: - Soli moisture, Structure, Nutrition, Texture, Aeration, Soil pH. c) Chemical Injuries: - Pollution, Pesticides. d) Improper Cultural Practices: - Depth of sowing, Improper irrigation, Improper fertilization, Improper harvesting.

10. Survival of Pathogen Soil Seed Plant debris/ crop residues Plants itself Collateral Host Alternate Host

11. Types of plant Diseases Biotic plant disease Disease caused by fungi. Disease caused by prokaryotes Disease caused by parasitic plants and green algae. Disease caused by virus and viroid‘s Disease caused by nematodes Disease caused by protozoan A biotic plant disease Disease caused by too low and too high temperature. Disease caused by lack of oxygen Disease caused by lack of sun light Disease caused by nutrients deficiency Disease caused by mineral toxicity Disease caused by toxicity of pesticide.

12. Disease Scenario Total Plant Diseases in the world - 80,000 In India - 5,000 types of plant diseases Average disease per plant - 100

13. Classification of Plant Disease According to affect on the host plant Localized diseases- Ex.- Rust of Wheat Systemic Diseases-Ex.- Loose Smut of Wheat According to symptoms & sign (i). Smut (ii). Rust (iii). Mildew (iv). Wilt (v). Blight (vi). Canker ( vii). Root rot

14. 3. According to parts of the plant affected Root diseases: - Affect root of plants. Ex. -Root rot of vegetables Stem diseases : - Affect stem of plants. Ex. - Stem gall of coriander . Foliar disease: - Affect foliar parts of plants. Ex. – Leaf spot of Sorghum . Fruit diseases: - Affect fruit of plants. Ex. - Fruit rot of Brinjal

15. 4. According to host plant affected Field crop diseases Vegetables crop diseases Fruit tree diseases Forest trees diseases Forage crop diseases 5. According to mode of perpetuation and spread Seed-borne diseases: - Ex.- Loose smut of wheat Soil-borne diseases: - Ex.- Sheath blight of rice Air-borne diseases: - Ex.- Rust of wheat

16. 6. According to occurrence (i). Endemic disease These disease appear in a ‘Limited area’. Diseases appear ‘Every Year’. These do not cause ‘More Loss’ Ex. - Early blight of potato. (ii). Epidemic or epiphytotic diseases These disease appear in a ‘Large Area’. Diseases appear ‘ Periodically’. These diseases cause ‘More Loss’ Ex. - Late blight of potato

17. (iii). Sporadic diseases These diseases are ‘Sporadic’ Appear on ‘Irregular Intervals’ These diseases cause ‘Less loss than epidemic diseases’ Ex. - Powdery mildew of mango (iv). Pandemic diseases These diseases appear in ‘Whole world/continent / sub continent ’ Appear at ‘Periodic Intervals’ These cause ‘Heavy Loss’ Ex. - Late blight of potato

18. The Disease triangle Disease Development: - The classic disease triangle establishes the conditions for disease development, i.e. the interaction of a susceptible host , a virulent pathogen and a favourable environment .

19. Plant disease triangle No Disease Environment (Unfavorable) Host (Susceptible) P a t ho g en (virulent)

20. Plant disease triangle No Disease Environment (Favorable) No n‐Ho s t (Immune) P a t ho g en (Avirulent)

21. Plant disease triangle Disease Environment (Favourable) Host (Susceptible) P a t ho g en (virulent)

22. Fungi: 10-15,000 Viruses: ~1,000 Nematodes: several 100 sp. Bacteria: ~100 sp. Plant Pathogens

23. Plant disease control: -

24. End Thanks