Management of soil born pathogens PATHO ppt.pptx

How to manage soil borne pathogens

1. Management of soil borne pathogens M. THAMARAISELVAN 2022002192

2. Soil borne pathogens: Soil-borne pathogens are disease-causing agents that live in soil and in plants, and can infect healthy plants growing in that soil. They can cause a variety of diseases, including root rots, damping-off, and wilts.

3. These diseases can reduce the efficiency of water and nutrient uptake, and can have a significant impact on agricultural production and farm productivity. So, management of soil borne pathogens are necessary for crop growth. Rhizopus solani Macrophomina phaseolina Phytopthora infestans

4. Methods of management of soil borne pathogens include: Sanitation Soilless culture Legal Methods Soil amendments Resistant Cultivars /Varieties and Grafting Anaerobic soil digestion • Soil steam sterilization Cropping System Chemical control
Soil Solarization Biological control Biofumigants .

5. SANITATION: •It includes activities which are aimed to prevent the spread of pathogens by removing diseased and infected plant parts, decontamination of tools and equipment and washing hands. •Weeds and volunteer plants should be destroyed as they can function as a host for pathogens as well as increase the relative humidity around the crop canopy, creating an environment in which many pathogens. LEGAL METHODS : •The long distance transfer of soilborneplant pathogens may occur through packing materials, containers, plant material, seeds, plant products,soil , animals or even humans. •Legal methods can be defined as any regulation, law or quarantine that prevents the movement of a disease-causing agent by country, region, state, or county.

6. Resistant Cultivars/Varieties and Grafting: One effective tool in is the development of resistant cultivars/varieties through plant breeding . Grafting is more popular in fruit vegetable crop. So, Grafting of susceptible scions on the compatible disease-resistant rootstocks is an important strategy for the management of soilborne plant pathogens. Some soilborne diseases such as bacterial wilt and root-knot nematode of solanaceous vegetables and Fusarium wilt of cucurbits are managed by grafting techniques Fusarium wilt in tomato Grafting in tomato

7. Cropping system: • Same crop in a field year after year, development and persistence soilborne pathogens is almost certain. Mixed cropping, intercropping and crop rotation are important practices. Crop rotation is a valuable method of plant disease management, but less effective against soilborne pathogens that have a wide host range. So, recommended to use the combination of disease-free planting materials and crop rotation For example, tomato should be rotated with legumes, cole crops, or lettuce but not within the Solanaceae family (eggplant, chili, potato etc.) to reduce Fusarium wilt Fusarium wilt in tomato

8. Soil Solarization : Soil solarization is a method of soil-disinfestation based on its solar heating by mulching a soil with a transparent polyethylene during the hot season, thereby controlling soilborne pathogens.

9. Biofumigantion : A sulfur compound, glucosinolate , is produced by Brassica crops and releases biologically active products upon hydrolysis such as isothiocyanates (ITC), which are found to be toxic to many soil organisms such as P. nicotianae and R. solani . This method has been used effectively against soilborne pathogens and is widely known as biofumigation Soil amendments: Organic manures made up of organic wastes, composts and peats, have been proposed to control soilborne diseases and pests. R. solani , Thielaviopsis basicola , V. dahliae , species of Fusarium,Phytophthora , Pythium and Sclerotium are found to be managed effectively by the application of organic amendments Anaerobic Soil Disinfestation : Anaerobic soil disinfestation (ASD), also known as biological soildisinfestation , is a process of disinfesting the soil by making it anaerobic using easily decomposable amendments such as ricebran , fresh crop residues, soybean flour and vineasses , covering it with plastic film, and irrigating to saturation.

10. Soil steam sterilization: •It is a technique to sterilize the soil by using hot steam in the open field, high tunnels or greenhouses •This method involves the injection of hot water vapors in the soil using boilers and conductors. •Steaming the soil was found to be effective compared to methyl bromide for root-knot nematode control in cut flower production in Florida Root knot nematodes in tuberose

11. Soilless culture: Soilless culture can help manage soil pathogens by separating plant growth from soil-related issues like soilborne diseases, salinity, and poor quality. However, some pathogens can still be found in soilless culture like Pythium and Phytophthora

12. Chemical control: Chemical control of soilborne plant pathogens is generally preferred in large crop production areas due to relatively rapid effect and easy operation. Products in the dicarboximide , benzamidazolr and triazole fungicide groups are known to control certain soilborne fungal disease effectively . Bilogical control: • Biological control involves the application of biocontrol agents in soil such as T. viride , T. harzianum , fluorescent Pseudomonas and B. subtilis • The application of biocontrol agents tothe soil is an alternative to suppress soilborne plant pathogens through parasitism, production of antagonistic chemicals, competition for the host and nutrients, and induction of resistance in plants against disease-causing pathogens

13. Conclusion: Soilborne diseases are among the most destructive elements in crop production. However, soilborne plant pathogens can be managed below the economic threshold level when these methods are applied as a system approach.

14. MCQ’S: Which of the following is the seed- borne disease management strategy? a.)Crop rotation b.)Chemical seed treatment c.)Biological control d.) All the above What is the purpose of seed disinfection? a.)To control fungal diseases b.)To control bacterial diseases c.)To control viral diseases d.) To control all the above Which method is used to detect seed-borne bacteria? a.) PCR b.)ELISA c.)Bioassay d.)Seed isolation What is the benefit of using treated seeds? a.)Increased yield b.) Improved quality c.)Reduced disease risk d.) All the above

15. Which of the following is a seed-borne fungal disease? a.)Damping off b.)Powdery mildew c.)Downy mildew d.) All the above Which includes the activities to prevent spread of pathogens by removing diseased plant part? a.) Sanitation b.) Contamination c.) Infection d.) Inoculation Which is the method of soil disinfestation based on its soil heating? a.)Soil drenching b.) Soil solarization c.) Sanitation d.)Soil contamination

16. Which method involves the injection of hot water vapours in the soil using boilers and conductors? a.) Soil solarization b.)Soil drenching c.) Soil steam sterilization d.)Soil sanitation Which of the following chemical agents is often used in soil fumigation to manage soil borne pathogens? a.)Copper sulphate b.)Glyphosate c.) Chloropicrin d.)Boron Which cultural practice can reduce the build –up soil pathogens? a.)Overwatering b.)Monoculture c.) Mulching and proper drainage d.)Continuous planting of same crop