RUBBER LEAF FALL

1. COLLEGE OFAGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
RUBBER LEAF FALL
STUDENT COURSE TEACHER
Miss . GLORY K S Dr. PARTHASARATHY.S
ID No : 2015021037 Asst. Professor ( Plant Pathology)

2. RUBBER LEAF FALL
• Abnormal leaf fall
• Secondary leaf fall

3. ABNORMAL LEAF FALL
CAUSATIVE AGENT
Phytophthora palmivora
ECONOMIC IMPORTANCE
Most destructive annually recurring disease
in India causing a loss of 38-50% in latex
yield.
High rainfall in the states of Kerala, Tamil
nadu and Karnataka favors the disease.

4. OCCURENCE
Malaysia
Indonesia
Brazil
China
Sri Lanka
Vietnam
Phillipines
Nigeria
Thailand
Liberia

5. SCIENTIFIC CLASSIFICATION
• Phylum : Heterokontophyta
• Class : Oomycota
• Order : Peronosporales
• Family : Peronosporaceae
• Genus : Phytophthora
• Species : P. palmivora

6. PATHOGEN CHARACTER
• Mycelium non septate,
hyaline and produces
sporangiophores which
bears numerous pear shaped
sporangia which releases
zoospores.
• Sexual spores are oospores
• Chlamydospores are resting
spores.

7. MODE OF SPREAD
Primary spread: Oospores and chlamydospores
Secondary spread: Wind borne zoospores from
sporangia.
FAVOURABLE CONDITIONS
High moisture favors the disease.

8. SYMPTOMS
• It occurs during june-august, while general leaf
fall occurs during december.
• On leaves dull grey, circular spots appear
which enlarge and become irregular.
• The petiole exhibit sunken spot. Affected fruits
rot. Leaves shed prematurely either green or
after turning coppery red.
• Affected leaf form a thick carpet of rotting
foliage which emits bad smell.

9. SYMPTOMS
Leaf fall Fruit rot

10. LIFE CYCLE
• Sporangia germinate directly by forming a
germtube or invasive hyphae, or it
differentiates into biflagellate zoospores.
• The zoospores move or swim actively in water
for short distances with the aid of their
flagella.
• Zoospores come in contact with the host.
• The settled zoospores germinate to give rise to
a germ tube and develops an appresorium for
penetrating into the plant epidermis.

11. • Vegetative hyphae grow and rapidly occupy
the intercellular spaces of plant tissues.
• Then bulb like structures called haustoria
develops as lateral branches from intercellular
hyphae for translocating nutrients to fungal
hyphae.

12. MANAGEMENT
• Prophylatic sprays prior to onset of south west
monsoon with bordeaux mixture 1%.
• Addition of ZnSo4 @ 0.2% improves the
efficacy.
• Spraying of oil based copper oxy chloride.

13. SECONDARY LEAF FALL
CAUSATIVE AGENT
Glomerella cingulata (Teleomorph)
Colletotrichum gloesporioides (Anamorph)

14. SCIENTIFIC CLASSIFICATION
• Kingdom : Fungi
• Division : Ascomycota
• Class : Sordariomycetes
• Order : Glomerellales
• Family : Glomerellaceae
• Genus : Colletotrichum
• Species : G. cingulata

15. PATHOGEN
• Mycelium septate and
hyaline at first and
later becomes light
brown .
• Conidiophores bear
single celled oblong
conidia .
• Perithecia bear ascus
which contains eight
ascospores

16. MODE OF SPREAD
• Primary : Ascospores.
• Secondary :Wind borne conidia.
FAVOURABLE CONDITION
• High humidity favors the disease.

17. SYMPTOMS
• Infects tender leaves, mostly at the leaf tip
region.
• Spots are small, brown in colour and is
surrounded by an yellow halo.
• Numerous spots coalesce and dry up leading to
defoliation.
• The infested leaves often crinkle and become
distorted before shedding.

18. Drying at the leaf tip

19. MANAGEMENT
• Spraying with bordeaux mixture 1% or copper
oxychloride 0.125% or carbendazim 0.05% at
10-15 days intervals is effective.

20. REFERENCES
• Thomas Petch .,The Diseases and Pests of the
Rubber tree., page no 98-121.
• M.R.Sethuraj., Ninan Mathew., Natural
Rubber., Elsinoe Science., page no 49-52.