This presentation covers the major diseases affecting pea (Pisum sativum), focusing on their causal agents, symptoms, disease cycles, and management strategies. Emphasis is placed on accurate identification, epidemiology, and integrated management practices. Key concepts include pathogen identification, symptomatology, disease cycle, epidemiology, and integrated disease management.
Introduction to Pea Diseases
Pea (Pisum sativum) is susceptible to several fungal diseases.
Major diseases include Fusarium wilt, powdery mildew, downy mildew, rust, and Ascochyta blight.
Effective management requires understanding pathogen biology and disease epidemiology.
Fusarium Wilt – Pathogen and Symptoms
Caused by Fusarium oxysporum f. sp. pisi.
Initial symptoms: drooping, yellowing, and premature leaf drop.
Pod formation is severely affected; collar region shows necrosis and discoloration.
Dark brown vascular discoloration visible in stem cross-section.
Fusarium Wilt – Disease Cycle and Management
Pathogen survives in soil for long periods; infects via root hairs.
Primary infection: soil, seed, water; secondary: conidia via rain splash.
Favored by soil temperatures of 23–27°C and warm weather.
Seed treatment with carbendazim (2 g/kg) and soil drenching with copper oxychloride (0.25%) recommended.
Powdery Mildew – Pathogen and Symptoms
Caused by Erysiphe pisi.
Appears as white powdery spots on leaves, stems, and pods.
Severely infected leaves become chlorotic, distorted, and may fall.
Pods may be small and malformed.
Powdery Mildew – Disease Cycle and Management
Spread by airborne spores; thrives in warm (15–25°C), humid (>70%) conditions.
Cultural control: use resistant varieties, destroy infected stubble, avoid adjacent sowing to previous pea fields.
Chemical control: sprays of benomyl, carbendazim, sulphur, or triadimefon as per recommended doses and intervals.
Downy Mildew – Pathogen and Symptoms
Caused by Peronospora viciae.
Grayish-white mold on lower leaf surface; yellowish area on upper side.
Infected leaves turn yellow, die; stems may be stunted and distorted.
Brown blotches and mold may develop on pods.
Downy Mildew – Disease Cycle and Management
Primary infection: soil, seed, water; secondary: sporangia via rain splash or wind.
Favored by high humidity and low temperatures (5–15°C).
Remove and burn diseased plants promptly to reduce inoculum.
Rust – Pathogen and Symptoms
Caused by Uromyces pisi.
Initial symptoms: leaf flecking, progressing to reddish-brown pustules.
Pustules merge, burst, and release brown spores; severe cases cause plant drying and yield loss.
Rust – Disease Cycle and Management
Survives on infected plant debris and alternate hosts (e.g., Euphorbia).
Favored by frequent precipitation, dew, and temperatures of 20–25°C.
Cultural control: destroy debris, crop rotation with non-legumes, mixed cropping.
Chemical control: sulphur or triadimefon sprays as per recommendations.
Ascochyta Blight – Pathogens and Symptoms
Caused by Ascochyta pisi, A. pinodes, and A. pinodella.
Symptoms: purplish-brown flecks on lower leaves, stems, tendrils; lesions enlarge and coalesce.
Severe infection causes foot rot (purplish-black lesions at soil line), lodging, and pod lesions.
Pod infection leads to small, discolored, or shrunken seeds.
Ascochyta Blight – Disease Cycle and Management
Ascospores spread by wind; conidia by rain splash.
Primary infection from diseased seed or soil debris.
Favored by warm, humid conditions (15–25°C).
Use resistant varieties (e.g., B-90, CDC Frontier, CDC Luna), seed treatment with thiabendazole, and crop rotation.
Summary: Integrated Disease Management in Pea
Combine cultural, chemical, and genetic resistance strategies for effective control.
Use certified disease-free seed and resistant varieties.
Practice crop rotation and field sanitation.
Apply fungicides judiciously based on disease monitoring and recommendations.
This presentation covers major diseases of cucurbits, including their symptoms, etiology, disease cycles, and management strategies. Emphasis is placed on accurate identification and integrated management of fungal, bacterial, and viral pathogens affecting cucurbit crops. Key concepts include disease diagnosis, pathogen biology, epidemiology, and control measures. Important academic keywords: pathogen, symptoms, disease cycle, management, cucurbits.
Introduction to Diseases of Cucurbits
Cucurbits include cucumber, melon, watermelon, pumpkin, squash, and gourds.
Major diseases: Downy mildew, Powdery mildew, Fusarium wilt, Angular leaf spot, Cucumber mosaic, and Tospovirus.
Diseases caused by fungi, bacteria, and viruses.
Effective management requires accurate diagnosis and integrated control strategies.
This presentation covers major diseases of brinjal (eggplant), focusing on their causal agents, symptoms, disease cycles, and management strategies. Emphasis is placed on identification, epidemiology, and integrated disease management. Key topics include little leaf, bacterial wilt, Phomopsis fruit rot, and Cercospora leaf spot. Important academic keywords: Phytoplasma, Ralstonia solanacearum, Phomopsis, epidemiology, management.
Introduction to Brinjal Diseases
Brinjal (Solanum melongena) is affected by several major diseases.
Diseases reduce yield and fruit quality significantly.
Understanding pathogens and symptoms is crucial for effective management.
Little Leaf Disease of Brinjal
Pathogen: Phytoplasma, localized in phloem sieve tubes.
This presentation covers the major diseases affecting tomatoes, including early blight, late blight, and various bacterial and viral diseases. Understanding these diseases is crucial for effective management and maintaining healthy crops.
Introduction to Tomato Diseases
Overview of diseases affecting tomatoes.
Importance of disease management in agriculture.
Focus on early blight, late blight, and bacterial diseases.
Causal Organisms of Tomato Diseases
Early Blight: Alternaria solani
Late Blight: Phytophthora infestans
Bacterial Wilt: Ralstonia solanacearum
Leaf Curl Virus: Tomato leaf curl virus
Early Blight Symptoms
Dark spots on older leaves, stems, and fruits.
Yield losses can reach 79% in severe cases.
Weakens plants, reducing fruit set.
Favorable Conditions for Early Blight
Temperatures between 15 to 27°C.
High humidity (>90%) and rainy weather.
Weak plants from June-July sowing are more susceptible.
Management of Early Blight
Use pathogen-free seeds and remove infected debris.
Water in the morning to minimize leaf wetness.
Implement crop rotation with non-Solanaceous crops.
Late Blight Overview
Caused by Phytophthora infestans.
Can infect leaves, stems, and fruits rapidly.
Historically linked to the Irish potato famine.
Symptoms of Late Blight
Dark brown blotches on leaves with green-gray edges.
Fruits develop dark, mushy spots.
High humidity leads to white fungal growth.
Favorable Conditions for Late Blight
High humidity (>90%) and low temperatures (10-25°C).