1) Powdery mildew is a fungal disease that causes considerable yield loss in the important oilseed crop castor. 2) The disease is caused by the fungus Leveillula taurica, which appears as white powdery growth on the lower leaf surface that can spread to the upper surface. 3) The fungus survives in soil and infects plants through airborne conidia spores, favoring humid conditions between 20-35 degrees Celsius for growth.

1. COLLEGE OFAGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
POWDERY MILDEW OF CASTOR
Student Course teacher
Samrithilakshmi.M Dr. S. Parthasarathy
2016021039 Assistant Professor., (Plant Pathology)

2. POWDERY MILDEW OF CASTOR
• Castor is one of the important oilseed crop.
• Powdery mildew disease causes considerable yield
loss in castor.

3. SYMPTOMS
• White patches of powdery growth appears on the
lower surface of the leaf.
• In severe infection the upper-surface is also covered
by the whitish growth of the fungus.
• Later, the leaves will turn yellow and dries up.

4. https://encrypted-tbn0.gstatic.com
POWDERY GROWTH ON CASTOR LEAF

5. SYSTEMATIC CLASSIFICATION
Kingdom Fungi
Phylum Ascomycota
Class Leotiomycetes
Subclass Leotiomycetidae
Order Erysiphales
Family Erysiphaceae
Genus Leveillula
Species L.taurica

6. PATHOGEN
• ANAMORPH – Oidiopsis taurica
• TELEOMORPH – Leveillula taurica

7. PATHOGEN CHARACTERS
• It is an obligate fungal pathogen from the phylum
Ascomycota.
• It is an endophytic pathogen and consists of hyphae
which are intercellular.
• The haustoria penetrate into some of the
parenchymatous cells.

8. • The conidiophores of the fungus are branched and
usually emerge through stomata in aggregation.
• The conidia are hyaline, varying in shape, bear
minute papilla-like projection at the broad end, and
are borne singly at the tip of each branch.
• These germinate readily in water producing a germ
tube from one end.

9. CONIDIA OF LEVEILLULA
https://www.researchgate.net/

10. CONIDIOPHORE EMERGING THROUGH STOMA
https://www.researchgate.net/

11. • This is a polycyclic disease, i.e., there is an initial
infection and secondary spread.
• The fungus survives in the soil through cleistothecia
and ascospores from asci infect the first lower most
leaves near the soil level.
• Secondary infection is by air-borne conidia.
DISEASE CYCLE

12. FAVOURABLE CONDITION
• Dry humid weather following rainfall.
• The disease develops at temperatures ranging from 20
to 35 ˚C, but 25 ̊ C is the optimum.
• A cool, humid climate is congenial to fungal infection
and colonization.

13. MANAGEMENT
• Resistant variety
Jawala
• Cultural method
The disease affected parts and plants
should be collected and burnt after harvest.

14. • Biological method
Spraying the crop with bio-control agent like
Trichoderma viride @ 5.0 g /lit of water.
• Chemical method
Dusting the crop with finely powdered
sulphur (Sulfex) @ 20-25 kg/ha.

15. • Spraying the crop with any one of the following
fungicides.
Tridemorph 80 EC – 0.5 ml/lit of water
Wettable sulphur 80 WP- 2.0-3.0 g/lit of water
Carbendazim 50 WP – 1.0 g/lit of water

16. REFERENCES
• Saha,L.R. (2015). “Handbook of Plant Diseases”.
Kalyani Publishers. Pp - 102.
• Das,P.C. (2018) “Plant Diseases”. Kalyani Publishers.
Pp - 135.
• https://link.springer.com>article