Jute & cotton diseases. Collected and edited by Syed zahid. Read book for details.

1. Jute & Cotton diseasesSyed Zahid Hasan, SAU, Sylhet

2. Stem rot of Jute
CO: Macrophomina phaseolina

3. Symptoms
 Premature fall of leaves and black
colored hard stem are seen in the field
 Fibers are rotten and exposed
 Small dot like pycnidia present all over
the stem and they also infect the seeds
 Infected seeds are discolored and
loss viability
 Pycnidiospores do not adhered if fingers
are rubbed over the infected stem

4. Black colored
rot on stem
Stem rot
affected
field
Rotten
fiber
Small dot like
pycnidia
Conidia of M.
phaseolina

5.  Moist weather and warm temperature
(above 300C)
 Use excess nitrogenous and low
potash fertilizer
Factors favoring disease
development

6. Disease cycle
1)-Infected seeds collateral
hosts and crop residues
serving as primary sources
infection
2)-Infected plant with
pycnidia (p) on the stem
3)-A portion of stem showing
pycnidia (p) & ostiole (os)
4)-Section of stem showing
pycnidium & pycnidiospores
5)-Capsule & seed infection
by air-borne pycnidiospores

7. Management principles
 Collection of seeds from healthy plants
 Collection and destruction of plant debris
and stubbles
 Rouging out the infected plants
 Use of balanced fertilizers
 Use resistant varieties like D-154, CVL-1,
CC-45, O-4, O-9897
 Seed treatment with Vitavax 200 and
Homai @ 0.3% of seed weight
 Application of Blitox-50 is @ 0.2% or
Dithane M-45 @ 0.2-0.3% for 2-3 times
at 15 days interval

8. Black band of jute
CO: Botryodiplodia theobromae

9.  Mostly mature plants are affected
 Black colored band girdled the stem
 The bark may split open longitudinally
at the later stage
 Numerous dots (pycnidia) like structures
formed all over the surface of the stem
 Pycnidiospores are adhered if fingers
are rubbed over the black band
Symptoms

10. Black colored
band on stem
Black colored
band girdled
the stem
Conidia of
Botryodiplodia
theobromae
Bark split open
longitudinally

11. Life cycle
 Same as Stem rot of Jute
Management principles
 Same as Stem rot of Jute
Factors favoring disease
development
 Same as Stem rot of Jute

12. Anthracnose of jute
CO: Colletotrichum corchori

13. Symptoms
 Anthracnose first appearance as yellowish
brown, depressed water soaked spots on
the stem, which soon turn into irregular
lesions of about 1 cm in length and a few
mm in width
 In most cases the lesions are elongated
having tapering ends and wide at the
middle giving spindle or eye shape
appearance
 The affected area becomes dead & cracks
in the center and the fibres are exposed
 Some times several spots may coalesce &
produce large cankerous lesions and
in many cases they girdle the stem

14. Elongated lesion
having tapering
ends and wide at
the middle giving
spindle or eye
shape appearance
Crack & large
cankerous lesions

15.  Same as Stem rot of Jute
Factors favoring disease
development

16. Disease cycle
1- Infected seeds and crop
residues serving as
primary sources
2- Infected plant with
Cankerous lesions (cl)
On the stem
3- A portion of affected
stem showing stick in the
centre of the lesion
4- Section of stem showing
acervulus with setae and
conidia
5- Capsule & seed infection
by air-borne conidia

17.  Rotation with Corchorus olitorious is
practiced as this species is immune
to anthracnose
 Other control measures are same as
stem rot of Jute
Management principles

18. Bacterial blight or
Angular leaf spot of cotton
CO: Xanthomonas campestris pv. malvacearum

19. Symptoms
 Lesions first appear as water soaked area
on lower surface of leaf
 With aged, they enlarge and turn brown
to black and become frequently coated
with a sugar-like film
 On cotyledons the lesions are round
to irregular
 The lesions are limited by veinlets and
appear to be angular in shape
 Black elongated lesions develop on young
stem, sometimes causing girdling and
death of the stem and this symptom is
often called black arm

20. Lesions first appear
as water soaked
area on leaf
Lesion enlarge
and turn brown
and become
coated with a
sugar-like film Black arm
Lesions
on ball

21.  High rainfall, and humidity as well
as warm temperatures
 Dampen or excess moist soil
 Poor drainage system
Factors favoring disease
development

22.  Using disease free seeds
 Decomposition of infected plant debris
can be accomplished by ploughing
after harvest
 Crop rotation with non-host for 3 to 4
years is useful for control
 Seed delinted with acid
 Cultivate resistant varieties
 Do not cultivate or move equipment
through fields when foliage is wet
Management principles

23. Fusarium wilt of cotton
CO: Fusarium oxysporum fsp. vasinfectum

24. Symptoms
 Yellowing, wilting, defoliated plant, and
plant death are the typical symptoms
 If a stem is cut lengthwise near the base,
its vascular tissues below the bark exhibit
a brownish or chocolate to blacking
discoloration through the entire stem

25. Yellowing
& wilting
Vascular tissues
below the bark
exhibit brownish
or chocolate to
blacking
discoloration
through the
entire stem

26.  Temperature between 25-320C
 Light sandy soil with acidic nature
 Infested planting materials
 Infested soil
 Deficiency of potash and excess
of nitrogen and phosphous
 Nematode (root-knot, reni form and
sting nematode) infested soil
Factors favoring disease
development

27.  Avoiding crop stresses (over-irrigation
and over-application of nitrogen)
 Remove and destroy infested plant
materials after harvest
 Growing only resistant varieties
 Weeds should be controlled
 Crop rotation with nematode
resistant crops
 Reduce nematode population
Management principles

28. Verticillium wilt of cotton
CO: Verticillium albo-atrum

29.  The outstanding symptom is consist of
interveinal chlorosis or necrosis or
mottled appearance of the leaves with
yellow color
 As the disease progress severe stunting
and premature defoliation occur
 When the stem cut close to the ground
a dark-browning discoloration or streak
of vascular system observed
Symptoms

30. Interveinal chlorosis
Interveinal
necrosis
Dark-browning
discoloration or
streak of vascular
system

31.  Cool air and soil temperatures
 High content of nitrogen and moisture
 Infested planting materials
 Infested soil
Factors favoring disease
development

32.  Rotation with corn, sorghum & soybean
 Remove & destroy infested plant materials
after harvest
 Use resistant or tolerant varieties
 Careful timing and control of irrigation
and nitrogen rate
Management principles

33. Seedling disease of cotton
Causal organism
Rhizoctonia solani
Pythium sp.
Thielaviopsis basicela
Fusarium sp.
Phoma exigua

34.  Symptoms include seed decay, decay of
the seedling before emergence
 Partial or complete girdling of the emerged
seedling stems and seedling root rot
 Seed and seedling disease is characterized
by a soft, watery rot and damping-off
 Damaged seedlings that emerge are pale,
stunted, slower growing, and sometimes die
within a few days
Symptoms

35. Seedling affected by
Rhizoctonia sp
Seedling
affected by
Pythium sp
Seedling affected by
Thielaviopsis basicela

36.  Planting too early in a cold
 Wet seed bed
Factors favoring disease
development

37.  Destroy Crop residue
 Crop rotation
 Lime acid soils
 Plant high-quality seed
 Plant in warm soil
 Plant on well-prepared seedbeds
and in well-drained soils
 Plant only treated seed
Management principles

38.  Applying fungicide like Demosan, Baytan,
Thiram, captan, chloroneb, and Terraclor
(PCNB) @ 0.2% are effective against
Rhizoctonia but not against Pythium
 Apron (metalaxyl) and Terrazole (ethazol)
@ 0.2% are effective against Pythium but
not the other fungi
 Baytan @ 0.2-0.3% is the only fungicide
that retards black root rot (Thielaviopsis)

39. Thanks To All