Leveillula taurica

Leveillula

1. Powdery mildew of Chilli,Onion and Cucurbits Janaharshini R 2018006015 II-Yr B.Sc.,( Hons )Horticulture HC&RIW, Trichy . Leveillula taurica

2. Systematic position Domain : Eukarya Kingdom : Fungi Phylum : Ascomycota Class : Leotiomycetes Subclass : Leotiomycetidae Order : Erysiphales Family : Erysiphaceae Genus : Leveillula Species : L. taurica

3. Leveillula taurica is an obligate fungal pathogen, from the Phylum Ascomycota . It causes powdery mildew on chilli,onion , redgram , tomato and castor. This disease prefers warm, dry environment. It is relatively easy to control through basic sanitation and reducing water stress. INTRODUCTION

4. SYMPTOMS Whitish fungal growth on the under surface of the leaf and the corresponding upper surface show yellow discolouration or chlorotic patches, later the disease spreads to entire leaf surface cause yellowing and defoliation of leaves . The disease progresses from the older to younger leaves and shedding of foliage is prominent symptom .

5. PARASITE CHARACTER Mycelium is endophytic , hyaline, septate and branched. Conidiophores emerge through stomata, single or in groups, simple or branched, septate and bear single conidium . Conidia are hyaline, single celled and clavate . Cleistothecia are with myceloid appendages, many asci per cleistothecium . Each ascus contains two curved ascospores .

6. FAVOURABLE CONDITION The disease is favored when large day/night temperature and humidity fluctuations occur, which promote periods of leaf wetness. Development of L. taurica is favored by warm (25°C) and dry (less than 80% RH) days followed by humid (greater than 85% RH) nights. Temperatures of 25°C are associated with a higher rate of disease development than temperatures of 18–20°C. Young plants are less susceptible than older plants.

7. MODE OF SPREAD AND SURVIVAL The main method of spreading the fungus is by wind , but rain splash will also spread the spores. Insects such as thrips , aphids and whiteflies are considered minor sources of spread. Workers handling affected plants may cause spores to be disseminated to neighboring plants.

8. MANAGEMENT Sanitation practices (removing and destroying infected crop debris and weed control) are not always sufficient to control the disease. Spray wettable sulphur 0.25% or Dinocap ( Karathane ) 0.05% Ensure good spray coverage witg protectant fungicides, particularly on the undersurface of the foliage and the llower plant canopy. Plant resistant plant material.

9. REFERENCE https://avrdc.org/wpfb-file/powdery%20mildew-pdf/ agritech.tnau.ac.in/ crop_protection /chilli_disease_3.html Leveillula taurica -Wikipedia