1. COLLEGE OFAGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
POWDERY MILDEW OF RED GRAM
Student Course teacher
Samrithilakshmi.M Dr. S. Parthasarathy
2016021039 Assistant Professor., (Plant Pathology)
2. SIGNIFICANCE
• Red gram is found to be one of the important crop in
India.
• Powdery mildew is also an important disease of Red
gram.
• This disease has been rarely reported to cause severe
losses.
4. OCCURRENCE
• The disease in India is reported to be prevalent during
Nov to March at Coimbatore.
• The disease occurs in all the Red gram growing areas
of India.
5. SYMPTOMS
• White powdery patches on the under surface of the
leaf.
• The corresponding upper portions just above the
patches will show yellow discolouration.
• Severe infection result in heavy defoliation.
• The disease causes stunting of young plants, followed
by the visible symptoms of white powdery growth.
12. 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.
13. • 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.
15. • 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.
• The secondary infection is by air-borne conidia.
DISEASE CYCLE
17. 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.
18. • But, a warm humid climate is good for sporulation
and spore dispersal.
• Survives on perennial pigeonpeas and volunteer
plants growing in the shade, and on the ratoon
growth of harvested stubbles.
• Early sowing and irrigation encourage disease
development.
19. MANAGEMENT
• Select fields away from perennial pigeonpeas affected
with the disease.
• The stubbles of previous crop and disease affected
plants should be collected and destroyed by burning.
• Late sowing should be avoided.
• Spraying wettable sulphur @ 2g /lit of water
effectively controls the disease.
20. • Dusting sulphur 80 WP @ 30.0 kg/ha checks the
spread of the disease.
The disease can be controlled by spraying any one of
the following fungicides starting just on the
appearance of the disease.
Carboxin 75 WP
Carbendazim 50 WP
Hexaconazole 5 EC
Myclobutanil 10 WP
Flucilazole 40 EC
