Horticultural Diseases_compressed_compressed_compressed.pdf

Horticulture

1. Course title –Diseases of Field &
Horticultural Crops & their
Management-II
Course No –APP5321
1

2. PowderyMildew
of Apple
2

3. Apple powdery mildew
Causal organism-
Podosphaera lecotricha
3

4. Symptom -
▪The infection usually starts as circular powdery white spots
▪which can affect leaves, stems and sometimes fruits .
▪It usually covers the upper parts of the leaves but may grow on the
undersides as well.
▪The fungus Hinders photosynthesis and cause the leaves turn yellow
and dry out and some leaves might twist , break or become disfigured .
▪In the later stages the buds and growing tips become disfigured.
4

5. Picture of Symptom -
5

6. ETIOLOGY
◼Sub-Division – Ascomycotina
◼Mycelium -septate, branched
◼ Superficial growth on host, establishing host relationship by
haustoria.
◼Asexual Spore - conidia ( formed in chain on conidiophores)
◼ Ellipsoidal to barrel shaped, hyaline, single celled
◼Conidiophore – Simple, unbranched, non-septate
6

7. ETIOLOGY
◼Ceistothecia - closed structures having appendages (Straight,
Bulbous base)
◼ Contain 1 Ascus
◼Asci - broadly elliptic to sub globose
◼Ascospores - Each ascus contains 8 ascospores
7

8. 8

9. Disease Cycle -
9

10. Disease Cycle of wheat powdery mildew
Pathogen survive in crop
debris as cleistothecia and
conidia
Infection on lower leaves
near soil line
Production of conidia
Symptom development
Infection in collateral host
Formation of Cleistothecia in
fallen leaves
Secondary spread by wind
Secondary
cycle
Disease cycle of Powdery mildew
Release of Ascospore
10

11. Favourable Condition -
Powdery mildew infections occur when the relative humidity
is grater than 70% and the temperature between 20-25℃
11

12. Management -
▪use resistant or tolerant varieties – Red delicious, Golden delicious
▪plant crops with sufficient spacing to allow for good air circulation.
▪Monitor fields regularly to assess the incidence of a disease or pest.
▪remove infected leaves when the first spots appear .
▪a thick layer of mulch can prevent the dispersal of spores from the soil up
onto the leaves.
12

13. Management -
▪Chemical Control-
▪Hexaconazole, Carbendazim, Karathane
▪5 Spray
▪1. Green tip stage
▪2. Open cluster
▪3. Full pink stage
▪4. petal fall stage
13

14. Management -
▪Biological Control-
▪Foliar sprays based on sulfer, neem oil, kodin or ascorbic acid can prevent
severe infection
▪Spray 5% urea for early decomposition
14

15. Lecture – Fire Blight of Apple
PRESENTED BY:- DEVENDRA CHOUDHARY
15

16. CAUSAL ORGANISM
Erwinia amylovora
16

17. SYMPTOM
▪Blossom Blight
▪Shoot Blight
▪Infected flowers appears water soaked and grey green, but
soon become brown or black
▪Petals of infected flowers fall off
17

18. SYMPTOM
▪After few weeks of petal fall, symptom appear on young
shoots
▪The young leaves and stems turn brown to black, and finally
wilt and fall off
▪Cankers appear on the stems, tree trunk and even roots
18

19. SYMPTOM
▪The infected branches are girdled and finally breaks
▪Infection in root results in death of plants
▪Oozing may be seen in the affected area
19

20. PICTURE OF SYMPTOM
20

21. PICTURE OF SYMPTOM
21

22. PICTURE OF SYMPTOM
22

23. ETIOLOGY
▪Kingdom – Bacteria
▪Gram stain – Negative
▪Cell shape – Rod
▪Flagella – Peritrichous
▪Respiration - Aerobic
▪Colony – Straw color to Yellowish and Diffused
23

24. 24

25. DISEASE CYCLE
Survival – Tree trunk
PI- In flower, through nectorthods
SI- Bees, Rain
Flower to Flower by Bees
25

26. 26

27. FAVOURABLE CONDITION
Temperature – 20-22℃
High relative Humidity >90%
Rain
Presence of Pollinator
27

28. MANAGEMENT
▪IDM
▪Sanitation
▪Selection of a resistant cultivar Red Delicious and Golden
Delicious
▪Removal of expanding and overwintering cankers (Regular
pruning)
▪Application of Pseudomonas fluorescence
28

29. MANAGEMENT
▪Control sucking insects - Sucking insects create wounds
through which fire blight bacteria can enter.
▪
▪Spray streptomycin at bloom -Streptomycin is an antibiotic
that can kill fire blight bacteria before they enter the apple
tree.
29

30. Apple Scab
30

31. CAUSAL ORGANISM
Ventura inaequalis
31

32. SYMPTOM
▪The disease usually noticed on leaves and fruits.
▪Affected leaves become twisted or puckered and have black,
circular spots on their upper surface.
▪On the under surface of leaves, the spots are velvety and
may coalesce to cover the whole leaf surface.
▪Severely affected leaves may turn yellow and drop.
32

33. SYMPTOM
▪Scab can also infect flower stems and cause flowers to drop.
▪The lesions later become sunken and brown and may have
spores around their margins
▪Infected fruit become distorted and may have cracks and
rough surface
33

34. PICTURE OF SYMPTOM
34

35. ETIOLOGY
◼Sub-Division – Ascomycotina
◼Class - Loculoascomycetes
◼Mycelium -septate, branched
◼Epidermal
◼Asexual Spore - conidia ( formed in chain on conidiophores)
◼ Flame shaped, hyaline, 1-2 celled
◼Conidiophore – Simple, unbranched, non-septate
35

36. ETIOLOGY
◼Sexual fruiting body – Pseudothecia
◼Ascospore – oval to boat shaped, yellowish in color, 2 celled
36

37. 37

38. DISEASE CYCLE
38

39. 39

40. FAVOURABLE CONDITION
▪18-24 ℃ temperature
▪Cool nights
▪Wet surface
▪>90% RH
40

41. MANAGEMENT
▪Sanitation
▪Urea 5% spray
▪Apply organic manure
▪Cover soil near trunk (Spread a 3- to 6-inch layer of compost
under trees)
▪Hexaconazole, Penclonazole or Mancozeb
▪(Avoid resistance development)
▪BCA - Chaetomium globosum
41

42. MANAGEMENT
▪Choose resistant varieties when possible – Macfree,
Freedom, Red free
42

43. Crown
gallof
Apple
43

44. Disease – Apple Crown Gall
Causal organism - Agrobacterium tumefaciens
(syn. Rhizobium radiobacter)
44

45. Symptom -
The bacteria stimulate the tree to produce plant hormones that cause a
tumor or gall to form.
The galls most commonly occur on the roots or on the trunk near the soil
line.
At first, the galls appear light-colored and spongy.
As the galls mature, they turn dark brown and woody.
45

46. Picture of Symptom -
46

47. Etiology -
▪Kingdom – Bacteria
▪Family – Rhizobiaceae
▪Gram stain – Negative
▪Cell shape – Rod
▪Flagella – Later
▪Respiration - Aerobic
▪Colony – White
47

48. 48

49. Disease Cycle -
•Crown gall is caused by a soil-borne bacterium that enters tree wounds
caused by mower damage, pruning, frost cracks, insects or planting damage
49

50. Pathogen survive in crop
debris + Soil + Infected
stem
Infection in Stem or Roots
Through Wounds
Production of Bcateria
Symptom development
Secondary spread through
Pruning knife, other tools or
Soils
Secondary
cycle
50

51. Favourable Condition -
▪28-30
0
temprature
▪Injury to plants
▪Presence of moisture on the host surface
▪susceptible variety
51

52. Management -
No cure exists for the disease, and it may kill a young apple tree by girdling
the stem.
A mature apple tree may be able to tolerate crown gall.
Carefully inspect apple trees to avoid purchasing a tree infected with crown
gall.
If a recently planted tree develops crown gall, remove the tree and adjacent
soil; the bacteria can persist for several years in the soil.
If your property has a history of crown gall infections, avoid planting fruit
trees or other susceptible plants.
52

53. Management -
▪When pruning, disinfect pruning tools between cuts. Use either a solution of
70% alcohol and 30% water, or a 10% bleach solution (1 part bleach with 9
parts water).
▪Biological control
▪A non-pathogenic (non-disease causing) strain of the same bacterium
(Agrobacterium radiobacter strain 84) has been used to protect plants
against infection by crown gall bacteria in the soil.
53

54. Chemical control
The copper-based solutions refer to copper fungicides such as copper
oxychloride, which seems to show the best results of the copper compounds
from my searches of the literature.
54

55. Gummosis
of
Citrus
55

56. 1. Disease - Citrus Gummosis
•Alternaria helianthi
Causal organism - Phytophthora nicotianae var. parasitica,
P. palmivora,
P. citrophthora
56

57. Symptom -
▪Disease starts as water soaked large patches on the basal portions of the stem
near the ground level.
▪Bark in such parts dries, shrinks and cracks and shreds in lengthwise vertical
strips.
▪Later profuse exudation of gum from the bark of the trunk occurs.
▪Considerable amount of gum formation in sweet oranges may be observed,
but relatively little in grapefruit.
▪Affected collar region is girdled and finally the infected tree dies
57

58. Picture of Symptom -
58

59. Etiology -
▪The pathogen produces non-septate and hyaline mycelium.
▪Sporangiophores-They are unbranched and bear single celled, hyaline,
round or oval sporangia at the tip singly.
▪Thesporangiagerminate to produce abundantzoospores.
▪The fungus also producesoosporesandchlamydosporesin adverse seasons.
59

60. 60

61. Disease Cycle -
Primary Infection: Oospores or as dormant mycelium
Secondary Infection : Sporangia and zoospores spread by
splashing rain water and irrigation water
61

62. Pathogen survive in Crop
debris as Oospore and
Chlamydospore
Infection through wounds or
Lenticle
Production of Sporangia
Symptom development
Secondary spread through
wind, rain, water
Secondary
cycle
62

63. Favourable Condition -
•The Phytophthora species causing gummosis develop rapidly under
moist and cool conditions.
•Prolonged direct contact of trunk with water, as in flood irrigation and
water
•logging predisposes trees to disease
•Incidence is more in black soils than in light soils
•High water table leads to high incidence
•The disease is severe in high rainfall areas
•Low budded grafts are mostly affected
63

64. Management -
•Always keep the orchard clean.
•Prune unproductive, dry and disease/ insect infected branches
•Use Bordeaux paste on wounds created by pruning and on the main
trunk from the ground well to about one meter high.
•Spray bordeaux mixture 1% thoroughly on the whole plant after
harvest and repeat again at fruit setting.
•Monitor the orchard regularly.
64

65. Management -
•Soil drenching with 0.2% Metalaxyl (Metalaxyl+Mancozeb = Ridomil MZ 72)
•Apply Trichoderma viride multiplied on neem cake
•Following Double ring method of irrigation by providing an inner ring about 45
cm around the tree trunk to prevent direct moistening of trunk
•Avoid injuries to crown roots or base of stem during cultural operations
•Use resistant sour orange or trifoliate orange rootstocks for propagating
popular/commercial varieties
65

66. Lecture – Citrus Canker
PRESENTED BY:- DEVENDRA CHOUDHARY
66

67. CAUSAL ORGANISM
Xanthomonas campestris pv. citri
67

68. SYMPTOM
▪ Symptoms appears on leaves, stems and fruits.
▪ Acid lime, lemon and grapefruit are affected.
▪Rare on sweet oranges and mandarins.
68

69. SYMPTOM
▪Leaves - Initially water soaked spots appear which
slowly turn brown and produce corky raised spots.
▪Followed by development of yellow hallow.
69

70. ▪Stem -
▪Same as on leaves but yellow hallow is absent,
▪bark eruption takes place and, bacteria oozing out
during warm rainy season from cracks.
▪Finally stem girdled and die.
70

71. ▪Fruits –
▪Brownish corky out growth with cracks and crater like
appearance at a later stage is the common symptom.
▪On fruits, canker lesions appears which reduces the
marketing quality.
71

72. PICTURE OF SYMPTOM
72

73. PICTURE OF SYMPTOM
73

74. 74

75. ETIOLOGY
▪Kingdom – Bacteria
▪Gram stain – Negative
▪Cell shape – Rod
▪Flagella – Monotrichous
▪Respiration - Aerobic
▪Colony – Straw color to Yellowish and Diffused
75

76. 76

77. DISEASE CYCLE
▪Survival :- pathogen survives in infected leaves for 6 months
.
▪PI :- the diseased twigs ( stems ) and leaves are the main
source of inoculum.
▪ The bacterium enters the host through stomata, Lenticle or
wounds.
▪ Secondary spread through wind, rain and insects.
77

78. Pathogen Survive in Plant
debris and host plant
Infection through wound and
stomata, Lenticels
Symptom development
Reproduction and multiplication
Bacterial ooze out of infected
area
Secondary spread through wind
and rain splashes
Secondary
cycle
DISEASE CYCLE of Citrus Canker
78

79. FAVOURABLE CONDITION
▪ 20-30 °C temperature
▪ high relative humidity (90%)
▪ Presence of moisture on the host surface
▪ Susceptible variety
▪ Infestation of Leaf minor larvae
79

80. FAVOURABLE CONDITION
80

81. MANAGEMENT
▪Cultural Management -
▪ Infected leaves, stem, fruit etc should be removed and Burnt
▪ Grow Resistant varieties Citron, Calmondin
▪Prune badly infected twigs before the on set off monsoon.
81

82. MANAGEMENT
▪ Quarantine Management –
▪ If area is disease free, restrict the entry of planting material
from infected area.
82

83. MANAGEMENT
▪Physical Management –
▪ Hot water treatment of root stocks at 50°C for 10-15
minutes.
▪Biological Management –
▪Pseudomonas fluorescence suspension can be sprayed as
biological control agent.
83

84. MANAGEMENT
▪Chemical Management –
▪ Spray Streptocycline sulphate 500-1000 ppm; or or Copper
oxychloride 0.2% at fortnight intervals on the plant
▪Control leaf miner when young flush is produced.
84

85. Lecture –
Grapevine Anthracnose
PRESENTED BY:-
Birds eye disease
85

86. CAUSAL ORGANISM
Telomorph - Elsinoe ampelina
Anamorph - Sphaceloma ampelinum
86

87. SYMPTOM
▪ The fungus attacks shoots, tendrils, petioles, leaves, stems
and also the inflorescence and berries.
87

88. SYMPTOM
▪Leaves :-
▪Small, irregular, dark brown spots.
▪The central tissue turn grey and falls.
▪Spots on petioles and leaves cause them to curl or become
distorted.
▪The spots are 7mm in diameter
88

89. SYMPTOM
▪ Shoots :-
▪Numerous spots occur on young shoots.
▪These spots may unite to girdle the stem and cause death of
the tips and may also cause die-back symptoms.
89

90. SYMPTOM
▪Berries :-
▪Characteristic round, brown sunken spots resembling “Birds
Eye” appear and hence the name of the disease.
▪The symptom appears as dark red spots on the berry.
90

91. PICTURE OF SYMPTOM
91

92. PICTURE OF SYMPTOM
92

93. ETIOLOGY
▪Sub-Division – Ascomycotina
▪Class - Loculoascomycetes
▪Mycelium – Septate, branched and Dark
▪Asexual Spore – Conidia - hyaline, single-celled, oblong or
ovoid
93

94. ETIOLOGY
▪Sexual fruiting body – Pseudothecia
▪Sexual Spore – produces ascospores in Asci
▪Asci :- Globular
▪Ascospore :- hyaline, 3-celled
94

95. 95

96. DISEASE CYCLE
Survival - pathogen survives in stems and infected twigs
PI - Through dormant mycelium, conidia and Pseudothecia
present in infected shoots and buds .
Secondary spread - through conidia which are carried by wind
and rain water
96

97. Pathogen Survive in stem, and
infected twigs as mycelium and
Pseudothecia
Infection in leaves, stems, tendrils
and berries
Symptom development
Production of Conidia and
Ascospores
Infection in collateral host
Secondary spread through
wind and rain water
Secondary
cycle
97

98. FAVOURABLE CONDITION
▪ Maximum temperature in the range of 27-31 °C.
▪ Relative humidity 90-100 %.
▪Warm wet weather with continuous drizzle of rain and windy
weather for 2-3 days
▪Low lying and ill drained soils
▪Susceptible variety.
▪Heavy rains after pruning
98

99. MANAGEMENT
Cultural Management -
▪ All cankerous vines should be pruned and burnt to remove
primary inoculum.
▪Training of vines should be done in a manner that water
splashes should not reach the foliage and branches during
rainy season.
▪Ground level branches should be removed.
99

100. MANAGEMENT
Varietal Resistance –
▪Varieties like Banglore blue, Golden Muscat, Golden queen
and Isabella are resistant
Quarantine Management –
▪ If area is disease free, restrict the entry of planting material
from infected to healthy area.
100

101. MANAGEMENT
Biological Management –
•Trichoderma spp. is used as a biological control agent.
101

102. MANAGEMENT
Chemical Management –
▪ Spray vineyards at the time of leaf emergence with benomyl
(0.1%), carbendazim (0.1%), or Bordeaux mixture (1.0%).
▪At least four sprays of fungicides should be given during rainy
season at fortnightly intervals.
102

103. Lecture –
Grapevine
Powdery Mildew
PRESENTED BY:-
103

104. CAUSAL ORGANISM
Uncinula necator
104

105. SYMPTOM
▪The disease attacks vines at any stage of growth.
▪All the aerial parts of the plant are attacked.
▪Cluster and berry infections usually appear first
105

106. SYMPTOM
▪Powdery growth is visible on older berries and the infection
results in the cracking of skin
of the berries.
▪Powdery growth mostly on the upper surface of the leaves
▪Infection of stem leads to dark brown discoloration
106

107. SYMPTOM
▪Floral infection results in shedding of flowers and poor fruit
set
▪Early berry infection results in shedding of affected berries
107

108. PICTURE OF SYMPTOM
108

109. PICTURE OF SYMPTOM
109

110. PICTURE OF SYMPTOM
110

111. PICTURE OF SYMPTOM
111

112. ETIOLOGY
▪Sub-Division – Ascomycotina
▪Class – Pyrenomycetes
▪Mycelium – Septate, branched and hyaline
▪Asexual Spore – Conidia
▪Asexual fruiting body – Naked
▪Conidiophore - Simple, vertical, unbranched
112

113. ETIOLOGY
▪Sexual Spore – Ascospore – Single celled
▪Sexual fruiting body – Cleistothecia
▪Cleistothecia – closed fruiting body, Circinate appendages
113

114. 114

115. 115

116. DISEASE CYCLE
▪Primary Infection:
▪Through dormant mycelium and conidia present in the
infected shoots and buds
▪Secondary Infection:
▪Through air-borne conidia
116

117. Pathogen survive in crop
debris as cleistothecia and
conidia
Infection on lower leaves
near soil line
Production of conidia
Symptom development
Formation of Cleistothecia in
fallen leaves
Secondary spread by wind
Secondary
cycle
Disease cycle of Powdery mildew
Release of Ascospore
117

118. FAVOURABLE CONDITION
▪Cool dry weather
▪Temperature in the range of 21-30 ℃
▪R.H. 40-100%
▪Most incidence (November and December)
118

119. MANAGEMENT
▪Clean cultivation of vines or removal and destruction of all
diseased parts
▪Grow resistant varieties like Black Prince, Sultana Red, Skibba
Red, Skibba White
119

120. MANAGEMENT
▪Spray NSKE 5% or Neem oil 3% twice at 10 days interval from initial
disease appearance.
▪Spray Eucalyptus leaf extract 10% at initiation of the disease and 10
days later.
▪Spray Carbendazim 500 g or wettable sulphur 1500g/ha or
Propiconazole 500 ml/ha or Karathane at initiation of the disease
and 10 days later
120

121. MANAGEMENT
▪Three spray of Chemical (S Dust or wettable sulphur)
▪1
st
– when shoots are 3-4 inch height
▪2
nd
– at flowering stage
▪3
rd
– after 2 month
121

122. Lecture –
Grapevine Downy
mildew
PRESENTED BY:-
122

123. CAUSAL ORGANISM
Plasmopara viticola
123

124. SYMPTOM
▪Irregular yellowish translucent spots on the upper surface of
the leaves.
▪On lower side of spots downy (Cottony) growth of fungus
can be seen
▪Symptoms upper on all aerial and tender parts of the vine.
▪Symptoms are more pronounced on leaves young shoots and
immature berries.
124

125. SYMPTOM
▪Infected leaves, shoots and tendrils are covered by whitish
growth of the fungus.
▪Dwarfing of tender shoots.
▪No cracking of the skin of the berries.
125

126. PICTURE OF SYMPTOM
126

127. PICTURE OF SYMPTOM
127

128. ETIOLOGY
▪Sub-Division – Mastigomycotina
▪Family – Perenosporaceae
▪Mycelium : Hyaline, coenocytic, intercellular with knob
shaped haustoria, branched.
▪Sporangiophores : branching @ right angles to the axis
128

129. ETIOLOGY
▪Sporangia : Hyaline, single celled, lemon shaped, Produce
zoospore after germination
▪Zoospore : Biflagellate
▪Oospore : Simple, double thick walled, spherical, 28-40 μm
in diameter.
129

130. 130

131. DISEASE CYCLE
•Survival – Oospore + Mycelium in Infected debris and
Infected parts
•PI - The primary infection of the disease is initiated from the
oospores.
•Secondary spread - sporangia and zoospores, which are
formed on the new shoots.
131

132. Oospore + Mycelium in
Infected debris and
Infected parts
Oospore germinate and
produce Sporangia >
Zoospore
Production of
Sporangia
Symptom development
Secondary spread through
wind, rain, water
Secondary
cycle
Disease cycle of DMD of Grapevine
Mycelium Produce
Sporangia > Zoospore
132

133. FAVOURABLE CONDITION
▪The most favorable temperature for germination of
Sporangia is between 10 – 23
0
C
▪Relative humidity is above 80%
▪Temperature is 23 and 27
0
C
133

134. MANAGEMENT
▪Regulatory measures
▪Restriction on the movement of planting material at
regional, national or international level should be imposed,
since the pathogen spread through dormant cuttings
134

135. MANAGEMENT
▪Cultural practice
▪Sanitation
▪All infected plant material and pruned parts must be removed
and burnt before bud sprouting, so as to reduce primary
inoculum.
▪Well drained soil
▪Good air movement
135

136. MANAGEMENT
▪Biological control
▪Erwinia herbicola, a saprophytic bacterium, used as liquid
culture and sprayed on vines which inhibits P. viticola upto
75%
136

137. Chemical control
▪5 Spray of Chemicals like
▪Foestly aluminium 0.2% or Metalaxyl 0.2% or Copper
oxychloride are effective
▪At
▪1. Just after pruning
▪2. 3-4 week after pruning
▪3. Before buds open
▪4. When berries has formed
▪5. During growth of shoots
137

138. Anthracnose of
Mango
138

139. Disease – Mango Anthracnose
Causal Organism - Colletotrichum gloeosporioides
139

140. Symptoms
▪Produces leaf spots, blossom blight, wither tip, twigs blight and fruit rot.
▪Small blister like spots develop on the leaves and twigs.
▪Large number of spots appears in leaves, coalesce to each other and cover
major portion of leaf lamina
▪Young leaves wither and dry
140

141. Symptoms
▪Tender twigs wither and die backsymptom appears.
▪Affected branches ultimately dry up.
▪Black spots appear on fruits.
▪The fruit pulp becomes hard, crack and decay at ripening. Infected fruits
drop
141

142. Picture of Symptom -
142

143. ETIOLOGY
▪Sub-Division – Deuteromycotina
▪Mycelium – Septate, branched and Dark
▪The mycelium of the fungus is localized in the spot.
▪Asexual Spore – Conidia - hyaline, single celledandfalcatein shape.
▪Asexual fruiting body – Acervullus
▪Acervuliwith setae arise through epidermis.
143

144. ETIOLOGY
▪Sexual fruiting body – Perithecia – Pear shaped, In Leaf
sheath
▪Also produce Chlamydospore
▪Colony colour – Black
144

145. 145

146. Disease Cycle -
146

147. Pathogen survive in crop
debris & infected portion
as conidia
Infection in leaves, stem,
Fruits
Production of conidia
Symptom development
Secondary spread through
wind
Secondary
cycle
147

148. Favourable Condition
➢25-30 ℃
➢High RH
➢Presence of free water
➢Dense planting
➢Shadow
148

149. Management -
➢Removal of infected buds, twigs, leaf from the orchard.
➢Pruning and cutting of heavily infected inflorescence twig.
➢Spraying of copper oxychloride, mancozeb @ 0.25 to 3 % at an interval of 7-
10 days starting from the rainy season.
➢Before storage ripen fruits should be treated in hot water at 50 ℃ for 15
minutes or dip in Benomyl solution (500 ppm) or Thiobendazole (1000 ppm)
for 5 minutes
149

150. Management -
➢Avoid over-crowding in orchards
➢Removal of fallen leaves
150

151. Bacterial
Blightof
Mango
151

152. Disease – Bacterial Spot or Bacterial Black spot or
Bacterial Canker
Xanthomonas campestris pv mangiferaeindicae

152

153. SYMPTOM
▪The disease is noticed on leaves, leaf stalks, stems, twigs, branches
and fruits
▪Initially producing water soaked lesions
▪later turning into irregular to angular raised lesions measuring 1-4
mm in diameter are formed.
▪These lesions are light yellow in colour, initially with yellow halo but
with age enlarge or coalesce to form irregular necrotic cankerous
patches with dark brown colour.
153

154. SYMPTOM
▪On fruits, water-soaked, dark brown to black coloured lesions are
observed which gradually developed into cankerous, raised or flat
spots.
▪These spots grow bigger usually up to 1 to 5 mm in diameter,
coalesce to each other and covers almost the whole fruit.
▪These spots often, burst extruding gummy substances containing
highly contagious bacterial cells.
154

155. PICTURE OF SYMPTOM
155

156. ETIOLOGY
▪Xanthomonas campestris pv mangiferaeindicae
▪Kingdom – Bacteria
▪Gram stain – Negative
▪Cell shape – Rod
▪Flagella – Monotrichous
▪Respiration - Aerobic
▪Colony – Straw color to Yellowish and Diffused
156

157. 157

158. DISEASE CYCLE
158

159. Pathogen Survive in Plant
debris and host plant
Infection through wound and
stomata, Lenticels
Symptom development
Reproduction and multiplication
Bacterial ooze out of infected
area
Secondary spread through wind
and rain splashes
Secondary
cycle
159

160. FAVOURABLE CONDITION
▪ 20-30 °C temperature
▪ high relative humidity (90%)
▪ Presence of moisture on the host surface
▪ Susceptible variety
▪ Mechanical injury
160

161. MANAGEMENT
▪Use healthy planting and grafting material.
▪Disinfect working tools and equipment.
▪Use resistant varieties if available.
▪Ensure good ventilation of the trees.
▪Regularly remove infected twigs, branches and fruits.
▪Avoid mechanical damage to the mango trees during field work.
▪Protect them from strong winds and heavy rains with windbreaks.
▪Infected fruits and tree material should be destroyed
161

162. MANAGEMENT
▪Spray Copper oxy chlorite at 15 days intervals
▪Collect fallen leaves and destroy
▪Apply Pseudomonas BCA
▪Apply proper nutrient , organic manure
▪Avoid sprinkler irrigation
▪Proper spacing
162

163. PRESENTED BY:- DEVENDRA CHOUDHARY
163

164. CAUSAL ORGANISM
Fusarium moniliforme var. subglutinans
Fusarium mangiferae
164

165. SYMPTOM
Two types of symptoms:
Floral malformation and
Vegetative malformation
165

166. SYMPTOM
▪Vegetative Malformation (VM) is more commonly found on
young seedlings.
▪The seedlings produce small shootlets bearing small scaly
leaves with a bunch like appearance on the shoot apex.
▪Seedling remains stunted and die while those getting
infected later resume normal growth.
166

167. SYMPTOM
▪Floral malformation (FM) is the malformation of panicles.
▪The severity of malformation may vary on the same shoot from
light to medium or heavy malformation of panicles.
▪Heavily malformed panicles are compact and overcrowded due to
larger flowers.
▪male and hermaphrodite flowers that are either sterile or
eventually abort
▪They continue to grow and remain as black masses of dry tissue
during summer but some of them continue to grow till the next
season.
167

168. PICTURE OF SYMPTOM
168

169. PICTURE OF SYMPTOM
169

170. PICTURE OF SYMPTOM
170

171. ETIOLOGY
▪Sub-Division – Deuteromycotina
▪Mycelium – Septate, branched and hyaline
▪Asexual Spore – Conidia
▪Asexual fruiting body – Sporodochia
▪Conidia – 1. macro conidia – boat shaped, hyaline, long, septate,
pointed at tip
2. micro conidia – small, curved, unicellular
▪Conidiophore – simple, slender, short, produced in
sporodochium
171

172. 172

173. DISEASE CYCLE
173

174. 174

175. FAVOURABLE CONDITION
Temperature – 20-25 ℃
High RH >80%
Mite infestation
175

176. MANAGEMENT
▪IDM
▪Diseased plants should be destroyed. Use disease free
planting material
▪Scion sticks from infected trees should not be used.
▪As soon as the disease appears, the affected terminals along
with the basal 15-20 cm healthy portion should be removed
or pruned and burnt.
▪If more than 25 per cent affected plants, de-blossoming at
bud burst stage should be done to delay the flowering.
176

177. MANAGEMENT
▪Spraying of Planofix (200 ppm) during the first week of
October followed by deblossoming at bud burst stage is
recommended.
▪A single foliar application of 1,000 ppm cobalt sulphate prior
to flower bud differentiation successfully reduce the floral
malformation.
▪Prochloraz sprays (0.1% concentration)
▪This is followed by the spraying of Carbendazim (0.1%) or
Captafol (0.2%).
177

178. Powdery
Mildewof
Mango
178

179. Disease- Mango powdery mildew

Causal organism - Oidium mangiferae
179

180. Symptoms
▪Disease mostly appear in February March
▪Symptoms appears on leaves, stalks of panicles, flowers and young fruits
▪Small, powdery white patches appears on leaves
▪Later it enlarge and cover entire leaf lamina
▪Fungus can also grow on stalks of panicles, flowers and young fruits
▪The affected flowers and fruits drop pre-maturely reducing the fruit set.
▪Often these patches coalesce and occupy larger areas turning into purplish
brown in colour
180

181. Picture of Symptom -
181

182. ETIOLOGY
◼Sub-Division – Ascomycotina
◼Mycelium -septate, branched
◼ Superficial growth on host, establishing host relationship by
haustoria.
◼Asexual Spore - conidia ( formed in chain on conidiophores)
◼ Ellipsoidal to barrel shaped, hyaline, single celled
◼Conidiophore – Simple, unbranched, non-septate
182

183. ETIOLOGY
◼Ceistothecia - None
◼Asci - None
◼Ascospores - None
183

184. 184

185. Disease Cycle -
185

186. Pathogen survive in crop
debris as conidia
Infection on lower leaves
near soil line
Production of conidia
Symptom development
Infection in collateral host
Secondary spread by wind
Secondary
cycle
Disease cycle of Powdery mildew
186

187. Favourable Condition -
▪Cloudy weather
▪Heavy moisture
▪Morning mist
▪20-25℃
▪70% RH max spore germination
187

188. Management -
▪No resistant variety is available
▪Chemical spray during flowering , fruit set
▪Topsin , Karathane , Bordedaux mixture
▪Carbendazim, Hexaconazole
▪Sanitation
▪Destroy crop residue
▪Proper nutrient application
▪Sulphur spray
188

189. Management -
▪Spray of 5% urea in fallen leaves for early decomposition
189

190. PRESENTED BY:-
190

191. CAUSAL ORGANISM
Taphrina deformans
191

192. SYMPTOM
▪The symptoms first appear in early spring
▪The leaves become twisted, thickened, puckered, curled
downward and often distorted.
▪In some leaves only a part of lamina are affected
192

193. SYMPTOM
▪In the beginning the affected leave are pale green or
yellowish but finally they change to a reddish purple.
▪On upper surface whitish fungal growth can be seen
193

194. SYMPTOM
▪Young shoot attached by fungus becomes twisted and
distorted.
▪Cause early defoliation and fruit drop
194

195. PICTURE OF SYMPTOM
195

196. ETIOLOGY
▪Sub-Division – Ascomycotina
▪Family – Taphrinaceae
▪Mycelium – Septate, branched and hyaline
▪Asexual Spore – None
▪Asexual fruiting body – None
▪Sexual Spore – Ascospores (8) in Naked Asci
196

197. ETIOLOGY
▪Ascospores – Globose, unicellular
▪Ascospores produce blastospore
197

198. 198

199. DISEASE CYCLE
199

200. 200

201. FAVOURABLE CONDITION
Temperature – 16-20 ℃
High RH >80%
Wet leaf surface for at least 12 hour
201

202. MANAGEMENT
▪IDM
▪Sanitation of Orchard
▪Bordeaux mixture (6:6:50) or Copper oxychloride (0.25%)
▪Chlorothalonil
▪Organic manure
202

203. Strawberry
leaf spot
203

204. Symptom -
▪ Symptoms appears on leaves, fruits, berry caps, petioles, and runners.
▪ Small, round, necrotic (i.e., dead) spots on strawberry leaves.
▪ Initially, these spots develop on the upper leaf surface and are deep purple
to red in color.
▪ The spots eventually develop tan, gray or almost white centers with distinct
reddish-purple to brown borders.
▪ During warm, humid weather, uniformly rusty-brown spots without purple
margins or light colored centers may develop instead.
204

205. Symptom -
▪ Spots can occur on the undersides of the leaves as well, but these spots
tend to be less vibrant in color.
▪ As the disease progresses, spots enlarge and may merge together, in
extreme cases leading to leaf death.
▪ Spots on berry, petioles, and runners resemble those produced on upper
leaf surfaces.
▪ Shallow, black spots may develop on infected fruits, and are often
surrounded by brown or black, leathery tissue.
205

206. 206

207. 207

208. Etiology -
Mycelium- septate, intercellular, branched
Perithecia- dark brown to black, erumpent, ostiolate and size -46.8 x70.0μ in
dia.
Ascus- oblong, clavate, size- 28.8-36.8 x 8-10 μ.
Ascospores- single septate, hyaline, ellipsoid, the upper cell slightly broader
and measure 11-14.5 x 2-3μ
Conidia- elongated, olive brown, narrow, one septate, measure 14-45 x 2-3
μ.
208

209. 209

210. Disease Cycle -
▪Fungus overwinters as mycelium, sclerotia, and perithecia in infected leaf
tissues
▪Spread - spores are spread by rain splash infecting new leaves as they
emerge in the spring when conditions are favorable
▪ Disease development is most successful in cool daytime temperatures and
cold nighttime temperatures, high relative humidity, and wet conditions.
210

211. Pathogen survive as
mycelium, sclerotia, and
perithecia in infected leaf
tissues
Infection in leaves, stem,
Fruits
Production of conidia
Symptom development
Secondary spread through
wind
Secondary
cycle
211

212. Favourable Condition -
➢High rainfall and warm temperatures are most favorable for this pathogen
and lead to rapid disease development.
➢ During mid to late spring, infections may be most severe due to frequent
rain showers.
➢The optimal temperature that will allow for most successful growth of the
pathogen and development of disease is around 25°C.
➢ The fungal pathogen favors 12 or more hours of leaf wetness for infection.
➢ New, young foliage has been found to be more susceptible to the pathogen
when compared to mature, developed foliage.
212

213. Management -
➢Field sanitation
➢Susceptible cultivars that should be avoided include Sparkle, Sunrise, Raritan
and Catskill.
➢ Grow resistant varieties like ‘Crimson King’, ‘Earliglow’, ‘Glooscap’,‘Ogallala’,
and ‘Ozark Beauty’.
➢Remove the older and infected leaves from runner plants
➢Take care in spacing runner plants in matted-row culture.
➢Plant in light, well-drained soil in a location exposed to all-day sun and good
air circulation.
213

214. •Control weeds in the planting. Weeds reduce air circulation and increase
drying time for leaves. (Leaves stay wet longer in weedy plantings.)
•Remove infected leaves after harvest
•Spraying of ferbam, Captan and benomyl 2g/lt , copper Oxy chloride (0.3%)
or Carbendazim (0.1%)
•Spraying of micronutrients- manganese, copper and boron at the time
•of sprouting in the spring and during budding.
214

215. Chilli
Wilt
215

216. Disease – Chilli Wilt
Causal organism - Fusarium oxysporum f.sp.capsici
216

217. Symptom -
➢Initially slight yellowing of the foliage and wilting of the upper leaves occurs
➢That progress in a few days into a permanent wilt with the leaves still
attached.
➢Upward and inward rolling of the leaves.
➢Later, the leaves turn yellow and die.
➢Generally appear localized in field where a high percentage of the plants wilt
and die
➢The vascular system of the plant is discolored, particularly in the lower stem
and roots
217

218. Picture of Symptom -
218

219. Picture of Symptom -
219

220. Etiology -
Mycelium :- Septate, branched, light pink
Conidia :-
Macro conidia - boat shaped, hyaline, long septate, pointed at tip
Micro conidia - small, curved, unicellular
Conidiophores:- simple, slender, short, produced in sporodochium
Chlamydospore:- spherical, thick walled

220

221. Macro conidia
Micro conidia
Sporodochium
Clamydospore
221

222. Disease Cycle -
Survival :- pathogen survives in soil and plant debris as mycelium and
chlamydospores.
PI :- dormant hyphae and chlamydospores in the soil
Secondary spread is through conidia & chlamydospores which are carried by
water and farm equipment.
222

223. Pathogen Survive in soil and
infected plant debris as mycelium
and chalmydospores
Infection in Roots
Infection in collateral host
Secondary spread through water
and Farm equipment
Secondary
cycle
Symptom development
Production of conidia
223

224. Favourable Condition -
➢Relatively high soil moisture and soil temperature
➢Heavy rainfall, excessive and frequent irrigation
➢poorly drained soil and close spacing
➢high soil moisture with temp around 25-30 °C
224

225. Management -
▪Field sanitation
▪Remove infected plants debris.
▪Apply neem cake or mustard cake to inhibit the growth of pathogen.
▪Drenching with 1% Bordeaux mixture or Carbendazim 0.25% or Mancozeb
may give protection.
▪Seed treatment with 4g Trichoderma formulation or 2g Carbendazim per kg
seed is effective.
▪Apply Trichoderma mixed with organic manure
▪Grow resistant cultivars/lines- DCA-3, DCA-7, DCA-8, DCA-21 and DCA-22.
225

226. Management -
▪Crop rotation with non host
▪Flooding of filed for 10 days if possible
▪Apply organic manure as much as possible
226

227. Anthracnose & Fruit
Rot of Chili & Capsicum
227

228. CAUSAL ORGANISM
Colletotrichum capsici
228

229. Symptoms
▪3 stage
▪Anthracnose
▪Die-back
▪Fruit rot
229

230. Anthracnose
▪Disease is more in December – October in transplanted crop
▪Small, circular to irregular, brownish black scattered spots
appear on leaves.
▪Severely infected leaves defoliate.
230

231. Die-Back
▪The disease causes necrosis of tender twigs from the tip to
backward.
▪The entire branch or the entire top of the plant may wither away.
▪Numerous black dots (acervuli of fungus) are found scattered all
over the necrotic surface of the affected twigs.
▪Only the top or few side branches may be killed or in severe
attacks the entire plant is withered.
▪Partially affected plants bear fruit which are few and low quality.
231

232. Ripe fruit rot
▪Small black circular spots are appeared on the skin of the
fruit and spread along the long axis of the fruit and thus
becoming more or less elliptical.
▪The spots are usually sunken with black margin.
▪Badly diseased fruit turn straw colour from normal color.
▪Sunken spots are covered with pinkish mass of fungal spores.
▪The fruits with many spots drop off prematurely, resulting
heavy loss in yield.
▪Seeds are also infected by this fungus.
232

233. PICTURE OF SYMPTOM
233

234. PICTURE OF SYMPTOM
234

235. ETIOLOGY
▪Sub-Division – Deuteromycotina
▪Mycelium – Septate, branched and Dark
▪The mycelium of the fungus is localized in the spot.
▪Asexual Spore – Conidia - hyaline, single
celledandfalcatein shape.
▪Asexual fruiting body – Acervullus
▪Acervuliwith setae arise through epidermis.
235

236. ETIOLOGY
▪Sexual fruiting body – Perithecia – Pear shaped, In Leaf
sheath
▪Also produce Chlamydospore
▪Colony colour – Black
236

237. 237

238. DISEASE CYCLE
▪Seed borne
▪Secondary spread is by air borne conidia & rain
▪Flies and other insects – responsible for dissemination of the
spores from one fruit to another
238

239. 239

240. FAVOURABLE CONDITION
▪Temp – 28-32 °C
▪RH - 95%
▪High humid conditions when rain occurs after the fruits have
started to ripe
▪ Susceptible variety.
240

241. MANAGEMENT
▪Deep summer ploughing
▪Organic manure
▪Application of Trichoderma & Pseudomonas fluorescence
▪Crop rotation with non host
▪Disease free seeds
241

242. MANAGEMENT
▪Seed treatment with Captan or Thiram 3-4g/kg
▪Avoid intercropping with susceptible turmeric cultivars
▪Collect and destroy all infected plant parts
▪Removal and destruction of Solanaceous weed hosts and
infected plant debris
▪Spray three times with Captan 1.5% or [email protected]%
just before flowering, at fruit formation stage and 15 days
after second spray
▪Resistant varieties: G3, G4, B61, Lorai, etc.
242

243. Leaf
spotof
Chilli
243

244. CAUSAL ORGANISM
Cercospora leaf spot - Cercospora capsici
Bacterial leaf spot - Xanthomonas campestris pv. vesicatoria
Alternaria leaf spot - Alternaria solani
244

245. SYMPTOM - Cercospora
▪Circular spots with brown margins and grey center appear on leaves
▪The spots enlarge and coalesce with each others
▪The central portion of the spot becomes white and the leaves turn yellow and
defoliate
▪Spots also appear on stems and twigs as dark brown, irregular lesions with
whitish centers
▪In severe cases die-back of twigs occur
245

246. SYMPTOM - Bacterial
▪Leaves, fruits and stems are affected
▪Lesions on leaf begin as circular, water soaked spots
▪Spots become necrotic with brown center with chlorotic borders
▪Enlarged spots may develop straw colored centers
▪Lesions are slightly raised on lower leaf surface
▪Severely spotted leaves turn yellow and drop
▪Raised brown lesions appear on fruits
▪Narrow elongated lesions or streaks may develop on stems
246

247. SYMPTOM - Alternaria
This is a common disease of chilli occurring on the foliage at any stage of the
growth.
The fungus attacks the foliage causing characteristic leaf spots and blight.
Early blight is first observed on the plants as small, black lesions mostly on the
older foliage.
Spots enlarge, and by the time they are one-fourth inch in diameter or larger,
concentric rings in a bull's eye pattern can be seen in the center of the
diseased area.
Tissue surrounding the spots may turn yellow. If high temperature and
humidity occur at this time, much of the foliage is killed.
247

248. SYMPTOM - Alternaria
Lesions on the stems are similar to those on leaves, sometimes girdle the
plant if they occur near the soil line.
The fungus also infects the fruit, generally through the calyx or stem
attachment.
Lesions attain considerable size, usually involving the entire fruit; concentric
rings are also present on the fruit.
248

249. PICTURE OF SYMPTOM
Cercospora
249

250. PICTURE OF SYMPTOM
Bacteria
Alternaria
250

251. Etiology - Cercospora
Mycelium – Septate, branched, light brown
Conidia – long, filiform, hyaline, multiseptated
Conidiophore – septate, simple, dark in color
Perfect stage – Mycosphaerella
251

252. Etiology - Alternaria
▪Mycelium – Septate, Branched and Dark
▪Conidia – Muriform (longitudinal and transverse
septation), dark, formed in chain
▪Conidiophore – short, dark colored, simple, septate
252

253. 253

254. Etiology - Xanthomonas
▪Kingdom – Bacteria
▪Family – Xanthomonadaceae
▪Gram stain – Negative
▪Cell shape – Rod
▪Flagella – Monotrichous
▪Respiration - Aerobic
▪Colony – Straw color to Yellowish and Diffused
254

255. 255

256. Disease Cycle -
256

257. Pathogen survive in crop
debris as conidia
Infection in leaves, stem,
seedling
Production of conidia
Symptom development
Secondary spread through
wind
Secondary
cycle
Disease cycle of leaf spot
257

258. FAVOURABLE CONDITION
Temperature 20-30℃
RH >80%
Imbalance fertilizer
Sprinkler irrigation
258

259. MANAGEMENT
▪Sanitation
▪Disease free seeds
▪Seed treatment
▪Trichoderma + Pseudomonas
▪Crop rotation
▪Organic manure
▪Spray of Fungicides (Mancozeb + Propiconazole + Cu
fungicides)
259

260. MANAGEMENT
▪Summer deep ploughing
260

261. Leaf curlof
Chilli
261

262. Disease - Chilli leaf curl
Cousal Organism - Chilli leaf curl virus
262

263. Symptom
◼Leaves curl towards midrib and become deformed.
◼Intense reduction in leaf size, short internodes, and dwarfing
◼Stunted plant growth due to shortened internodes and leaves greatly reduced
in size.
◼Flower buds abcise before attaining full size and anthers do not contain pollen
grains.
◼Failure of formation of fruits.
◼If fruits are formed, they remain small, deformed and poor in quality.
263

264. Picture of Symptom 264

265. Etiology
◼Chilli leaf curl virus (ChiLCV)
◼Genome – SS- DNA
◼Protein coat – Geminate particle
◼Genus Begomovirus and Family Geminiviridae.
◼This virus is transmitted by whitefly Bemisia tabaci.
265

266. 266

267. Disease Cycle 267

268. Virus survive in viruliferous
Insect and weed host
viruliferous Insect feed on
healthy Plants
Symptom
development
Multiplication & systemic
movement of Virus in Plants
Viruliferous Insect feed on
collateral host
Non- viruliferous insect feed
on infected plant and
become viruliferous
Secondary
cycle
268

269. Favourable Condition
▪Presence of virus
▪Dense planting
▪High dose of Nitrogenous fertilizer
▪Varity susceptible to Insect
▪High relative humidity
▪Cloudy days
269

270. Management
◼IDM
◼The infected plants should be uprooted and burnt or buried to avoid further
infection.
◼Avoid monoculture of chilli crop.
◼Selection of healthy and disease - free seed.
◼Suitable insecticidal sprays reduce the incidence of viral diseases, since
majority of viral diseases are transmitted by insect vectors.
270

271. ◼Nursery beds should be covered with nylon net or straw to protect the
seedlings from viral infection.
◼Raise 2-3 rows of maize or sorghum as border crop to restrict the spread of
aphid vectors.
◼Apply Imidacloprid in the mainfield to control sucking complex and insect
vectors selectively.
◼Collect and destroy infected virus plants as soon as they are noticed.
271

272. Stem gall
of
Coriander
272

273. CAUSAL ORGANISM
Protomyces macrosporus
273

274. SYMPTOM
▪The disease appears in the form of tumor-like
swellings of leaf veins, leaf stalks, peduncles, stems
as well as fruits.
▪The infected veins show a swollen hanging
appearance to the leaves.
▪Initially the tumors are glossy which rupture later on
and become rough.
274

275. SYMPTOM
▪They are about 3 mm broad and up to 12.5 mm
long.
▪Badly affected plants may be killed in the presence
of excessive soil moisture, especially under shaded
conditions, when the stem fails to harden and
remain succulent, the tumors are numerous
275

276. 276

277. ETIOLOGY
▪Sub-Division – Ascomycotina
▪Class – Hemiascomycetes
▪Mycelium - Septate and Branched, Hyaline
▪Sexual spore – Ascospore, Developed on asci
▪Asci developed naked on Mycelium
▪Ascospore multiply like yeast cell
277

278. 278

279. DISEASE CYCLE
279

280. Pathogen Survive in soil and
infected plant debris as
chlamydospores
Release of Ascospore
Secondary spread through wind,
water
Symptom development
Production & Multiplication
of Ascospore
Infection
280

281. FAVOURABLE CONDITION
▪20-25℃
▪>80% RH
▪Dense planting
▪Excessive soil moisture
▪Shades
281

282. MANAGEMENT
▪Deep ploughing of fields during summer
▪Soil solarization: Cover the beds with polythene sheet of 45
gauge (0.45 mm) thickness for three weeks before sowing for
soil solarization which will help in reducing the soil-borne
pests
▪Timely and line sowing should be done.
▪Avoid overcrowding
282

283. MANAGEMENT
▪Field sanitation
▪Rouging
▪Destroy the weeds
▪Soil test based application of manures and fertilizers.
283

284. MANAGEMENT
▪Apply Trichoderma
▪Maintain the optimum moisture to minimize the stem gall.
▪Hexaconazole as seed treatment (0.2%) and foliar spray after
40,60 and 75 DAS (0.2%) is more effective treatment for
management of stem gall disease of coriander
284

285. 285

286. cucumber, pumpkin,
squash Bottle gourd,
Ridge gourd, Bitter
gourd and watermelon.
286

287. Disease- Cucurbits Downy Mildew
Causal organism - Pseudoperonospora cubensis

287

288. Symptom -
▪Angular, chlorotic lesions on the upper surface of leaves
▪These lesions appear angular because they are bound by leaf veins.
▪During humid conditions, inspection of the underside of the leaf reveals
gray-brown to purplish-black cottony growth of pathogen
▪Eventually, leaves will turn necrotic and curl upwards.
▪The disease is sometimes called “wildfire” because of how rapidly it
progresses, as if the crop were burned by fire.
288

289. Symptom -
▪Symptoms on watermelon is different than on other cucurbits;
leaf spots are typically not angular and turn brown to black in
color.
▪Often, an exaggerated upward leaf curling will occur. Regardless
of which cucurbit is involved, only the leaves are infected (i.e.,
not fruit, flowers, stems or roots).
289

290. 290

291. Picture of Symptom -
291

292. 292

293. Etiology -
◼It is an biotroph
◼Mycelium - Hyaline, coenocytic, intercellular
◼Haustoria - Finger shaped
◼Sporangiophores - Hyaline, long, branched dichotomously
◼Sporangia - Hyaline, thin walled, germinate and produce Zoospore
◼Sub-Division - Mastigomycotina
293

294. 294

295. Disease Cycle -
▪The fungus survives in the soil and plant debris
▪
▪Disease can develop quickly when conditions are cold (5 - 15°C) and
humid over 90 per cent for 4 - 5 days, often when seedlings are in the
early vegetative stage
295

296. Oospore in Infected debris
Oospore germinate and
Infect plants
Production of
Sporangia > Conidia
Symptom development
Secondary spread through
wind, rain, water
Secondary
cycle
296

297. Favourable Condition -
◼Relative humidity is above 90%
◼Temperature is 15 and 20 ℃
◼More conidia production in 13-18℃
◼Intermittent rain
◼Cloudy days
297

298. MANAGEMENT
▪Sanitation
▪Crop rotation
▪Summer deep ploughing
▪Eradication of weed host
▪Chemical - Fosetly aluminium 0.2% or Metalaxyl 0.2% or
Copper oxychloride are effective
298

299. Powdery
Mildew of
Cucurbits
299

300. Disease - Cucurbits Powdery Mildew
Causal Organism – Sphaerotheca fuliginea
Erysiphe cichoracearum
300

301. Symptom
◼On upper surface of leaves, small white or greyish superficial spots appears.
◼Sometimes on stem too
◼Cover entire leaf lamina
◼Cause necrosis
◼Cause Defoliation
◼Fruits remains small and deformed,
◼Yield also reduced
301

302. Picture of Symptom 302

303. ETIOLOGY
◼Sub-Division – Ascomycotina
◼Mycelium -septate, branched
◼ Superficial growth on host, establishing host relationship by
haustoria.
◼Asexual Spore - conidia ( formed in chain on conidiophores)
◼ Ellipsoidal to barrel shaped, hyaline, single celled
◼Conidiophore – Simple, unbranched, non-septate
303

304. ETIOLOGY
◼Ceistothecia - closed structures having appendages
(Myceloid / Simple)
◼Asci - broadly elliptic to sub globose
◼Ascospores - Each ascus contains 8 ascospores
304

305. 305

306. Disease Cycle of wheat powdery mildew
Pathogen survive in crop
debris as cleistothecia and
conidia
Infection on lower leaves
near soil line
Production of conidia
Symptom development
Infection in collateral host
Formation of Cleistothecia in
fallen leaves
Secondary spread by wind
Secondary
cycle
Disease cycle of Powdery mildew
Release of Ascospore
306

307. Favourable Condition
◼RH 70%
◼Temperature – 20-25℃
◼Monocropping
307

308. Management
◼Clean cultivation
◼Crop rotation
◼Proper spacing
◼Remove weed host
◼Use of biocontrol agent – Ampelomyces quisqualis
◼Verticillium lecanii
308

309. ◼CHEMICAL CONTROL - Fungicides such as triadimefon and propiconazole,
effective chemical control is also possible with hexaconazole, penconazole.
309

310. Wilt
Disease of
Cucurbits
310

311. Disease – CucurbitsWilt
CausalOrganism–Erwiniatracheiphila
311

312. Symptom -
▪The area around the wound becoming dark green, and later the entire
plant shows a dull green color.
▪Leaves droop without yellowing
▪Later entire vines wilted
▪Striped or spotted cucumber beetles will be present in the field.
▪If infected vines are cut close to the crown of the plant and the cross
sections pressed together, thread-like strands of bacterial ooze are visible
when the two halves are gently pulled apart again.
312

313. 313

314. Symptom -
▪Seedlings are usually more susceptible to infection because they collapse
faster that full grown plants
▪Fruit on vines may fail to mature, resulting in complete economic loss
314

315. Picture of Symptom -
315

316. Etiology -
▪Kingdom – Bacteria
▪Gram stain – Negative
▪Cell shape – Rod
▪Flagella – Peritrichous
▪Respiration - Aerobic
▪Colony – Straw color to Yellowish and Diffused
316

317. 317

318. Disease Cycle -
Primaryinfection: Bacteria survive on striped cucumber
beetle and Spotted beetle.
Secondary infection: Spread by striped cucumber beetle.
318

319. 319

320. Favourable Condition -
▪Mono cropping of cucurbits plantation.
▪Stripped cucumber beetle population
▪Dense cropping
▪High dose of N
2 Fertilizer
▪High relative humidity
▪Cloudy days
320

321. Management -
▪In general, more bacterial wilt is seen on the edges of fields where beetles
first encounter plants.
▪Larger plantings must be protected by insecticides.
▪Carbaryl, Malathion, or rotenone insecticides or combination products are
registered to treat cucumber beetles.
▪They will provide control of the beetles if applied when beetles first appear
in the spring.
321

322. ▪Avoid mono-cropping of cucurbits
▪Sanitation
▪Removes weeds
▪Collect disease free seeds
▪Cover the rows with organic mulch or polythene
▪Apply neem oil every forth night
322

323. Stemphylium blight&
Purple Blotchof
Onion & Garlic
323

324. Disease–
onion& garlicstemphyliumblight
causal organism-
Stemphyliumvesicarium
324

325. Symptom-
▪The first symptoms of the disease appear on the radical leaves
as small, yellow to pale orange flecks or streaks in the middle of
leaf, which soon become elongated, spindle shaped to ovate
spots, surrounded by characteristic pinkishmargin.
▪Thesespots turngreyatthecentreandthenbecome
brown to dark brown with the development of
conidiophores and conidia of the pathogen.
▪Similar symptoms appearon theinflorescencestalks.
325

326. PictureofSymptom-
326

327. Etiology-
▪Sub-Division – Deuteromycotina
▪Mycelium – Branched, Dark, Septate
▪Conidiophores are straight to curved, 1-4 septa, simple or branched, light
yellowbrown tomediumgolden brownincolour
▪Conidia – Vertical + Horizontal septa present
▪Colony – Black (Concentric ring present)
327

328. 328

329. DiseaseCycle-
329

330. Pathogen survive in crop
debris as conidia
Infection in leaves
Production of conidia
Symptom development
Secondary spread through
wind
Secondary
cycle
330

331. FavourableCondition-
▪Warmand Humid climate
▪Temperature - 18-25°C
▪Leaf wetness period > 12hours favourdiseasedevelopment
▪Intermittent rain
▪Cloudy days
331

332. Management-
▪collectionanddestructionof plant debris
▪crop rotation
▪summer ploughings
▪Spraysofmancozeb(0.25%)
▪Proper spacing for air circulation
▪Ensure adequate drainage before planting.
▪Avoid excessive nitrogen applications which can increase disease
severity
▪Remove and bury plant debris and culls through cultivation after harvest
▪Use crop rotation for a period of 3-4 year
332

333. Management-
▪Application of BCA – Trichoderma
▪Organic Manure
▪Neem cake
333

334. Purple
Blotch of
Onion
334

335. Disease - Purple Blotch of Onion

CAUSAL ORGANISM
अल्टरनेररयापोरी
Alternaria porri
335

336. SYMPTOM
▪Leaves - whitish minute dots on leaves with irregular chlorotic
areas on tip portion
▪Circular to oblong concentric black velvety rings appear in
chlorotic area
▪Lesions develop towards the base of the leaves
▪Leaves die from the tip downwards, break at the point of infection
and hang down
▪Bulbs – semi watery rot, shrinkage of the fleshy bulb scales and
desiccation followed by these scales becoming dry and papery
336

337. PICTURE OF SYMPTOM
337

338. बीमारीकीशुरुआत
338

339. Etiology -
▪Mycelium – Septate, Branched and Dark
▪Conidia – Muriform (longitudinal and transverse
septation), dark, formed in chain
▪Conidiophore – short, dark colored, simple, septate
▪Perfect stage - Pleospora
339

340. 340

341. Disease Cycle -
341

342. Pathogen survive in crop
debris as conidia
Infection in leaves
Production of conidia
Symptom development
Secondary spread through
wind
Secondary
cycle
342

343. FAVOURABLE CONDITION
▪Warm and Humid climate
▪Temperature - 18-25°C
▪Intermittent rain
▪Cloudy days
▪Leaf Minor
343

344. 344

345. बीमारीकाप्रबंधन
१. रासायननकदवाई–
२. गर्मीकेर्महीनेर्मेंखेतकीगहरीजुताई
३. स्प्रिंकलरकाउपयोगनाकरें
४. ज्यादार्मात्रार्मेंनत्रजनकाउपयोगनाकरें
५. ट्राइकोडर्माायासूडोर्मोनासकाउपयोगकरें
६. बारबारएकहीखेतर्मेंप्याज़कीखेतीसेबचें
345

346. प्याजकेबैगनीधब्बा
रोगकाप्रबंधन
PurpleBlotch of Onion
346

347. बीमारीकेकारक
✓कवक–अल्टरनेररयापोरी
✓स्पोर–
347

348. बीमारीकेलक्षण
348

349. बीमारीकीशुरुआत
349

350. बीमारीकाप्रबंधन
१.रासायननकदवाई–
350

351. 351

352. 352

353. 353

354. 354

355. कब, कैसेऔरककतनीमात्रा
मेंदवाईकाउपयोगकरें?
355

356. प्रति टंकी (15 लीटर) =
30-40 ग्राम
प्रति लीटर =
2-3 ग्राम
356

357. प्रति टंकी (15 लीटर) =
15 ममली लीटर
प्रति लीटर =
1 ममली लीटर
357

358. प्रति टंकी (15 लीटर) =
20-25 ग्राम
प्रति लीटर =
1.5 ग्राम
358

359. रोपाई
पौधेकीबढ़वार
िुड़ाई
परिी
359

360. बीमारीकाप्रबंधन
२. गर्मीकेर्महीनेर्मेंखेतकीगहरीजुताई
360

361. बीमारीकाप्रबंधन
३. स्प्रिंकलरकाउपयोगनाकरें
361

362. बीमारीकाप्रबंधन
४. ज्यादार्मात्रार्मेंनत्रजनउर्वरककाउपयोगना
करें
362

363. बीमारीकाप्रबंधन
५. ट्राइकोडर्मावयासूडोर्मोनासकाउपयोगकरें
363

364. बीमारीकाप्रबंधन
६. बारबारएकहीखेतर्मेंप्याज़कीखेतीसेबचें
364

365. बीमारीकाप्रबंधन
१. रासायननकदर्ाई–
२. गर्मीकेर्महीनेर्मेंखेतकीगहरीजुताई
३. स्प्रिंकलरकाउपयोगनाकरें
४. ज्यादार्मात्रार्मेंनत्रजनकाउपयोगनाकरें
५. ट्राइकोडर्मावयासूडोर्मोनासकाउपयोगकरें
६. बारबारएकहीखेतर्मेंप्याज़कीखेतीसेबचें
365

366. ध्यानरखनेयोग्यबािें–
366

367. ध्यानरखनेयोग्यबािें–
१. एकदर्ाईकोसभीरोगोकेललएरयोगनहीिंकरनाचाहहए।
२. रोगकारककेहहसाबसेदर्ाई/ रबिंधनवर्धधकाननधावरणकरना
चाहहए।
रोगकारक–कर्क
जीर्ाणु
वर्षाणु
कीड़ेर्मकोड़े
367

368. ध्यानरखनेयोग्यबािें–
३. दर्ाईकीर्मात्रालसफ़ाररशर्मात्रासेज्यादानहीिंहोनाचाहहए।
४. पहलेऔरदूसरेदर्ाईरयोगकेबीचकुछहदनोंकाअिंतरालहोना
चाहहए।
५. अगरबाररशहोनेर्ालीहोतोरासायननकदर्ाईकेउपयोगसे
बचनाचाहहए।
368

369. Early
Blightof
Potato
369

370. Disease - Potato early blight
Causal organism - Alternaria solani

370

371. Symptom -
▪This is a common disease of tomato occurring on the foliage at
any stage of the growth.
▪As small, black lesions mostly on the older foliage.
▪Spots enlarge up to 3-4 cm in diameter or larger
▪concentric rings developed in the center of the diseased area.
▪Seedling infection cause collar rot
371

372. Symptom -
▪Tissue surrounding the spots may turn yellow
▪If high temperature and humidity occur at this time, much of
the foliage is killed.
▪Lesions on the stems are similar to those on leaves, sometimes
girdling the plant if they occur near the soil line.
372

373. Picture of Symptom -
373

374. Etiology -
▪Mycelium – Septate, Branched and Dark
▪Conidia – Muriform (longitudinal and transverse
septation), dark, formed in chain
▪Conidiophore – short, dark colored, simple, septate
▪Perfect stage - Pleospora
374

375. 375

376. Disease Cycle -
376

377. Pathogen survive in crop
debris as conidia
Infection in leaves, stem,
seedling
Production of conidia
Symptom development
Secondary spread through
wind
Secondary
cycle
Disease cycle of Early leaf spot
377

378. Favourable Condition -
▪Early blight is principally a disease of aging plant tissue.
▪Lesions generally appear quickly under warm, moist conditions
on older foliage and are usually visible within 5-7 days after
infection.
▪A long wet period is required for sporulation but it can also occur
under conditions of alternating wet and dry periods.
▪T = 24-30 ℃
▪RH = >90%
▪Cloudy days
378

379. Management -
▪Prune or stake plants to improve air circulation and reduce
fungal problems.
▪Keep the soil under plants clean and free of debris.
▪Add a layer of organic compost to prevent the spores from
splashing back up onto vegetation.
▪Drip irrigation can be used to help keep the foliage dry.
379

380. Management -
▪Crop rotation with non host
▪Removal and burning of infected crop debris and weed host
▪Application of organic manure
▪Spray Mancozeb 2 kg/ha in 15 days interval.
380

381. Late
Blightof
Potato
381

382. Disease - Potato Late blight
Causal organism - Phytopthora infestans

382

383. Symptom -
▪Water soaked lesions appears on edge of leaves
▪Later it turns to large, brown patches with a green gray edge;
not confined by major leaf veins.
▪Infections progress through leaflets and petioles, resulting in
large sections of brown foliage.
383

384. Symptom -
▪Lesions also girdle the Stem
▪Dark brown, circular spots cover large parts of fruits, leading to
dry brown rot
▪In high humidity, thin powdery white fungal growth appears on
infected leaves and stems.
▪In cool, wet weather, entire fields turn brown and wilted
384

385. Symptom -
▪Some time the plants look like stem without any single leaf.
▪Symptoms also extended to tuber portion either in fields or
during harvesting and storage.
▪Brown discolorations are seen on the skin of the potato tuber
followed by decaying and rotting of tubers
385

386. Picture of Symptom -
386

387. Etiology -
▪Sub-Division – Mastigomycotina
▪Family – Pythiaceae
▪Mycelium - non-septate, Branched and hyaline
▪Asexual Spore - Sporangia > Zoospore
▪Sporangiophoresemerge through the stomata on the lower
surface singly or in groups.
▪They are unbranched and bear single celled, hyaline, round or oval
sporangia at the tip singly.
387

388. ▪Thesporangiagerminate to produce abundantzoospores.
▪The fungus also producesoosporesandchlamydosporesin adverse
seasons.
388

389. 389

390. Disease Cycle -
390

391. Pathogen survive in Crop
debris as Oospore and
Chlamydospore
Infection through Stomata
Production of Sporangia
Symptom development
Secondary spread through
wind, rain, water
Secondary
cycle
Disease cycle of Phytophthora blight
391

392. Favourable Condition -
▪T = 20-22°C
▪>90% RH
▪Cloudy days
▪Intermittent rains
▪Dense cropping
▪Poor drainage of soil
392

393. Management -
▪Sanitation - Removal of infected plant debris i.e. infected leaves,
shoots, tubers etc. from infested potato fields
▪Proper drainage
▪Selection of healthy seeds
▪Avoid cutting of Tuber before planting
393

394. Management -
▪2-3 times deep summer ploughing during hot summer days
followed by irrigation
▪Crop rotation with non host crops i.e. beans, okra, cruciferous
vegetables, cereals, oil seeds and pulses
▪Do not allow field to field irigation specially from diseased fields to
healthy fields
394

395. Management -
▪Resistant cultivars – variety kufri Badsah, Kufri Naveen, Kufri Sinduri, Kufri
Alankar, Kufri jawahar, Kufri Ashoka, Kufri Anand, Kufri Giriraj and Kufri
Jeevan
▪Seed treatment with mancozeb
▪Foliar application of Ridomil (0.1%)
▪Soil application of Trichoderma bioformulation @ 25kg/ha
395

396. Black
scurfof
Potato
396

397. Disease - Potato Black scurf
Causal organism - Rhizoctonia solani
397

398. Symptom -
▪Two type
▪1. Black Scurf
▪2. Stem Canker
▪Raised, hard, black patches, irregular in size or shape, on the surface of the
tuber.
▪These are readily rubbed or scraped off
398

399. Symptom -
▪Sunken, brown lesions develop on the sprouts before they emerge from the
soil
▪In severe cases the tip of the sprout is killed.
▪often shoots again emerge from lower side, but emergence is delayed
▪Rough, brown, sunken patches develop on the stem, below soil level
▪If these girdle the stem then stunting and wilting often results, sometimes
with the production of small, green, aerial tubers in the junction between
the stem and leaf stalk
399

400. Picture of Symptom -
400

401. Etiology -
▪Sub-Division - Basidiomycotina
▪Mycelium : Septate, branched more or less at right angle, white
when young and brown when old constricted at the point of
origin, multinucleate
▪Sclerotia : Brown to black,uniform texture, more or less loosely
packed, irregular in size, usually spherical.
401

402. 402

403. Disease Cycle -
◼The sclerotia on the seed tubers is the principal source of
infection of the subsequent crop raised with tubers.
◼On favourable conditions the mycelium present in the soil
may develop producing new hyphae.
403

404. Infection in stem,
root, tuber
Symptom
development
Production of
sclerotia
Secondary spread
through tillage,
irrigation water
Pathogen survive in
soil, weed host as
sclerotia & mycelium
Secondary cycle
404

405. Favourable Condition -
◼Development of disease is favored by soil temperature between 16 to
25°C
◼while soil temperature is above 25°C reduce the severity of Disease
◼Acid soil is most favorable
◼It more severe in soil that are cool and moist
405

406. Management -
▪Disease free seed tubers should be planted
▪Shallow planting to avoid disease
▪Crop rotation for 2-3 years
▪Tuber treatment by boric acid @3%, dip for 25-30 min.
▪or Trichoderma 10 g/lt for 10-15 min
▪Sanitation
▪Application of Organic manure
406

407. Potato
Leafroll
407

408. Disease – Leaf roll of potato
causal organism- Potato leaf roll virus
408

409. Symptom -
▪ Infection in the growing season occurs in the youngest leaves.
▪A slight rolling and red/orange tinge can occur in the upper leaves.
▪The bottom leaves may roll and the leaves becomes dry, brittle and
papery
▪The plant show a slight yellow and upturning of the upper leaves.
▪Plant growth extremely reduced
▪Death of growing points of plants
409

410. Picture of Symptom -
410

411. Picture of Symptom -
411

412. Etiology -
◼Potato leafroll virus (PLRV)
◼Genome – SS- RNA
◼Protein coat – Spherical / Icosahedral
◼Genus Polerovirus and Family Luteoviridae.
◼This virus is transmitted by Aphid
412

413. 413

414. Disease Cycle -
414

415. 415

416. Favourable Condition -
◼Dense planting
◼Insect vector
◼Cloudy days
416

417. Management -
◼use seed tubers from healthy plants or use certified seeds.
◼Use resiatant varieties.
◼Monitor the field ,pick and destroy disease plants.
◼Destroy weeds and volunter plants that can host the virus
and feed the aphids.
417

418. ◼Direct treatment of the virus is not possible,but reducing
aphid population by means of predators of parasitoids.
◼Parasitic wasps could also be used.
◼Apply insecticides in the early phase of crop growth.
◼Crop rotation
418

419. Mosaic of
Potato
419

420. Disease – Potato mosaic
Causal Organism

1- Mild mosaic - Potato virus X (PVX)
2- Super mild mosaic - Potato virus - A
3- Severe mosaic - Potato virus Y ( PVY)
4- Rugose mosaic of potato - Potato virus X and potato virus Y
420

421. Symptom -
The disease is characterized by light and green mottling on the leaves
The leaflets of affected leaves are usually distorted, puckered and smaller than normal.
The affected plant appears stunted, pale green
Eye buds of the tubers are killed.
Plants grown from infected tubers are stunted with brittle and crinkled leaves.
421

422. Picture of Symptom
Mosaic virus
Super mosaic
virus
Severe mosaic Rugose mosaic
422

423. Etiology -
▪Potato virus X (PVX)
▪Genome – SS- RNA
▪Protein coat – Flexious rod (640 × 12nm)
▪Genus Potexvirus and Family Alfaflexiviridae.
▪This virus is transmitted by Contact.
423

424. 424

425. Disease Cycle -
425

426. Virus survive in collateral ,
perennial and weed host
Plant infected with contact,
or during inter-culture
operation
Symptom development
Multiplication of Virus in
Plant
Plant infected with contact,
or during inter-culture
operation
Secondary
cycle
Systemic movement of virus
in plant
426

427. Favourable Condition -
▪ 20-30 ℃
▪ High RH
▪ Cloudy days
427

428. Management
▪Selection of tubers from the healthy field.
▪Crop rotation with cereals and pulses.
▪Removal of alternate and collateral host from the fields.
▪Removal of infected tubers from the field.
▪Rouging of infected plants just after the initiation of symptoms.
▪Spray of Imidachloprid @ 0.3 ml/ l water for the control of insect vector.
▪Detopping of the potato plants before maturity to check the spread of virus from foliage to tubers
428

429. Leaf
spotof
Turmeric
429

430. Disease – Turmeric leaf spot
Causal organism – Colletotrichum capsici
430

431. 431

432. Symptom -
•Fungus attacks only leaves and usually infection is confined to leaf
blades and occasionally extend to leaf sheaths
•On leaves, elliptical to oblong brown spots with grey centers appear
•Spots are about 4-5 cm in length and 2-3 cm in width.
•They are surrounded by yellow halos
432

433. Symptom -
•Spots enlarge and cover a major portion of leaf blade.
•In advanced stages of disease, black dots representing
fungalacervulioccur in concentric rings on spot.
•The grey centers become thin and gets teared
• Severely effected leaves dry and wilt
433

434. Picture of Symptom -
434

435. ETIOLOGY
▪Sub-Division – Deuteromycotina
▪Mycelium – Septate, branched and Dark
▪The mycelium of the fungus is localized in the spot.
▪Asexual Spore – Conidia - hyaline, single
celledandfalcatein shape.
▪Asexual fruiting body – Acervullus
▪Acervuliwith setae arise through epidermis.
435

436. ETIOLOGY
▪Sexual fruiting body – Perithecia – Pear shaped, In Leaf
sheath
▪Also produce Chlamydospore
▪Colony colour – Black
436

437. 437

438. Disease Cycle -
Survival :- pathogen survives in seed rhizomes or infected
plant debris
PI :-Through mycellium and conidia present in infected plant
debris.
• Secondary spread is through conidia which are carried by
wind and water.
438

439. Pathogen Survive in Seed
Rhizomes and infected plant
debris as mycelium and conidia
Infection through stomata
Infection in collateral host
Secondary spread through
wind and water
Secondary
cycle
Symptom development
Production of conidia
439

440. Favourable Condition -
▪Temperature of 21-23 °C.
▪ Relative humidity 80%
▪ Intermittent rains
▪ Infected rhizomes
▪ Susceptible variety
▪ Planting long duration varieties
440

441. Management -
Cultural Management -
•The infected and dried leaves should be collected and burnt in order to reduce
the inoculum source in the field
• Crop rotations should be followed whenever possible.
• Select seed material from disease free areas.
Varietal Resistance –
•Cultivate tolerant varieties like Suguna and Sudarshan.
441

442. Biological Management –
•Trichoderma spp. is used as a biological control agent.
Chemical Management –
• Treat seed material with mancozeb @ 3g/litre of water or
carbendazim @ 1 g/litre of water, for 30 minutes and shade dry before
sowing.
• Spray mancozeb @ 2.5 g/litre of water or carbendazim @ 1g/litre; 2-3
sprays at fortnightly intervals
442

443. Rhizopus
rot of
Jackfruit
443

444. Disease: Jackfruit Rhizopus rot
Causal Organism - Rhizopus artocurpi
444

445. Symptom:-
▪Young fruits and male inflorescences are
badly attacked by the fungus and only a
small percentage of the fruits reach
maturity.
▪Female inflorescence and matured fruits
are not usually attacked.
▪At first, soft, watery, brown spots
develop on the flowers and fruit.
445

446. ▪Subsequently, a powdery, fuzzy-looking
mass of black spores and white fungal
mycelia covers the jackfruit surface.
▪Resulting, characteristic black, rotten,
shrunken, and sometimes mummified
fruit remains.
▪Fruit symptoms can appear on the tree
or can develop on fruit that are in
storage or transit.
446

447. Etiology:-
▪Sub-Division – Zygomycotina
▪Family – Mucoraceae
▪Mycelium – Coenocytic / Aseptate, branched and dark
colored
▪It produces many aerial stolon and rhizoids
▪Asexual Spore – Sporangia
447

448. Etiology:-
▪Sporangia are globose and black in colour with a central
▪columella.
▪Sexual Spore – Zygospore
▪Sporangiospore - aplanate, dark coloured and ovoid.
448

449. 449

450. 450

451. Favourable condition:-
▪Temperature ranging from 25 – 30°C
▪ Relative humidity of 90 – 100% favours high intensity of rot.
▪ Susceptible variety
451

452. Managment:-
▪Prune the tree to encourage good ventilation.
▪Remove and destroy diseased fruit from trees and the ground.
▪Clean up decaying organic debris within and around the tree.
▪Ensure that water does not pond around the tree’s root zone.
▪Control weeds around young trees.
▪Intercrop jackfruit with trees that are not susceptible to infection by
Rhizopus.
▪Keep ripe fruit from contact with the soil or decaying organic material.
452

453. ▪Avoid wounding the fruit.
▪Wash fruit after harvest in clean water and dry thoroughly before packing or
transporting.
▪Do not pack fruit with symptoms—destroy them.
▪Protect fruit with periodic sprays of copper fungicides or other products
registered for use on jackfruit
▪Can be spray mancozeb fungicide 2.5g/lit.
453

454. 454

455. CAUSAL ORGANISM
Podosphaera pannosa
455

456. SYMPTOM
▪Small powdery white patches appears on all aerial part of
plant
▪In case of severe attack, plants may become stunted, leaves
may curl, become dried, and drop.
▪Unopened buds, young stems, and thorns may be entirely
overgrown with the powdery coating.
456

457. PICTURE OF SYMPTOM
457

458. ETIOLOGY
◼Sub-Division – Ascomycotina
◼Mycelium -septate, branched
◼ Superficial growth on host, establishing host relationship by
haustoria.
◼Asexual Spore - conidia ( formed in chain on conidiophores)
◼ Ellipsoidal to barrel shaped, hyaline, single celled
◼Conidiophore – Simple, unbranched, non-septate
458

459. ETIOLOGY
◼Ceistothecia - closed structures having appendages
(Branched Dichotomously)
◼Asci - broadly elliptic to sub globose
◼Ascospores - Each ascus contains 8 ascospores
459

460. 460

461. DISEASE CYCLE
461

462. 462

463. FAVOURABLE CONDITION
▪RH 70%
▪Temperature – 20-25℃
▪Monocropping
463

464. MANAGEMENT
▪Clean up and dispose of fallen leaves and debris surrounding
plants.
▪Prune infected plant parts and dispose them properly.
▪Provide plants with adequate nutrients and water to
maintain their immunity
▪Keep the soil well watered and mulched to prevent moisture
loss and to cover up overwintering spores.
▪Space plants far enough apart to provide good air circulation
and prune them regularly to prevent overcrowding.
464

465. MANAGEMENT
▪Use fans to provide adequate ventilation during humid
nights.
▪Water the roses in morning so the foliage can dry rapidly and
to avoid infection by other fungal pathogens.
▪Use fungicides as a preventive measure during optimal
growth conditions.
▪Chemical - Fungicides such as propiconazole & hexaconazole
465

466. Lecture –
Black Spots
of Rose
PRESENTED BY:-
466

467. CAUSAL ORGANISM
Diplocarpon rosae
467

468. SYMPTOM
▪Black spots, one-tenth to one-half inch in diameter, develop
first on upper leaf surfaces.
▪Areas adjacent to the black spots turn yellow and leaves
drop prematurely,
▪Usually symptoms first appears at the bottom of the plant
and progressing upward.
468

469. SYMPTOM
▪Fungus may also attack stems and flowers of rose bushes
▪On stems, infected areas are blackened with blistered
appearance dotted with pustules
469

470. PICTURE OF SYMPTOM
470

471. PICTURE OF SYMPTOM
471

472. ETIOLOGY
▪Sub-Division – Ascomycotina
▪Class – Discomycetes
▪Mycelium – Septate, branched and hyaline
▪Asexual Spore – Conidia - Bicelled
▪Asexual fruiting body – Acervullus
▪Conidiophore - Simple, vertical, unbranched
▪Sexual Spore – Ascospore in Sexual fruiting body –
Apothecia
472

473. 473

474. DISEASE CYCLE
Survival - in fallen leaves and lesions on stems
PI - Spores are splashed onto the leaves and causeinfectionwhen
provided with seven hours of moisture, and optimal
temperaturesranging between20-26°Cwithhigh relative humidity.
SI - Within two weeks of infectionand the necessary moisture and
temperatures, more spores are produced, allowing for rapid infection
of nearby healthy rose plants during the growing season.
474

475. Pathogen survive in crop
debris as Apothecia and
conidia
Infection on lower leaves
near soil line
Production of conidia in
Acervulli
Symptom development
Formation of Apothecia in
fallen leaves
Secondary spread by wind
Secondary
cycle
Release of Ascospore
475

476. FAVOURABLE CONDITION
▪Temperature 20–26°C
▪High RH >90%
▪Presence of free water in plant surface
▪Shade
▪Susceptible variety
476

477. MANAGEMENT
▪Remove diseased leaves. As soon as diseased leaves are
noticed, remove and dispose of them.
▪Dead leaves on the ground should also be collected and
destroyed.
▪Compost only if this material will not be used back in rose
beds.
▪To minimize overwintering of the fungus, collect and remove
all leaves from the ground in the fall, mulch with 2–3 inches
of leaf mold or fine bark, and prune diseased canes before
growth begins in spring
477

478. MANAGEMENT
▪Keep the foliage dry. The fungal spores need a wet surface to
germinate and cause infection. Therefore, keep the foliage as
dry as possible.
▪Do not use overhead watering, or if you do, water early in
the day so the foliage is dry by night time.
▪Prune plants to allow more air circulation and facilitate the
drying of foliage.
478

479. MANAGEMENT
▪Move the plants - You can limit the disease by growing roses
in locations where they receive morning or, preferably, all
day sun. This facilitates drying of the foliage.
▪Resistant varieties: Bebe bune, Coronado, Grand opera,
Sphinx
▪Spray Tridemorph 0.1% at weekly intervals starting with the
sprouting of the plants till new foliage appears
479

480. Rose
Dieback
480

481. Disease - Rose Dieback
Causal organism:- Botrytis cinerea
481

482. Symptom -
▪Browning and Dieback of the tips of young shoots in spring
▪Browning and Dieback of a pruning stub, which the progresses further down
▪the branch
▪Dieback of twigs, branches, main stem or even the whole plant at any time
of year
▪Fungal structure, such as tiny black fruiting bodies, are sometime visible on
the affected parts of the plant.
▪In some instances there may also be associated root decay.
482

483. Picture of Symptom -
483

484. Etiology-
▪ Sub-Division – Deuteromycotina
▪ Mycelium – Septate, branched and hyaline
▪ Asexual Spore – Conidia (Globose)
▪ Conidiophore – Highly branched
▪ Colony color – Dark
▪ Produce sclerotia
484

485. 485

486. 486

487. ▪Both overwatering and underwatering can cause this problem.
▪Another cause is poor soil quality with no proper nutrients.
▪Cloudy days
▪20-25 ℃
▪High RH
Favourable condition:-
487

488. Management -
▪Sanitation
▪Sterilization of pruning knife
▪Proper organic manure
▪Regular pruning
▪Maintain proper spacing
▪Proper soil drainage
▪Avoid injury the plant during transplanting
▪Paste fungicides (Bordeaux paste) on cut portion
▪Spray Carbendazim, Mancozeb
488

489. Management -
▪Proper nutrition
▪Regular watering
▪Proper sunlight
▪Spray Trichoderma
489

490. Botrytisblight of
Marigold
490

491. Marigold- botrytisblight
Causalorganism -Botrytiscinerea
DKC
491

492. Symptom-
▪Flowerpartsdevelop water-soakedlesionsthat
become necroticanddie.
▪Agraymass ofsporesdevelops onnecrotictissue
during wetconditions.
▪Entirepetals orflowersmaybecomediseased.
▪Senescent leavesmayalso beattacked.
492

493. PictureofSymptom-
493

494. Etiology-
▪ Sub-Division – Deuteromycotina
▪ Mycelium – Septate, branched and hyaline
▪ Asexual Spore – Conidia (Globose)
▪ Conidiophore – Highly branched
▪Colony color – Dark
▪Produce sclerotia
494

495. 495

496. 496

497. DiseaseCycle-
Botrytisfungioverwinterassclerotiaondeadplantdebrisin
the garden.
In the spring, spores form and spread by wind or splashing
watertoinfectdying,wounded,orextremelysoftplanttissues.
Fungal mycelial strands (web blight) from previously infected
plantpartscangrow ontohealthyplantpartsandinfect them.
497

498. Pathogen survive in crop
debris + seed as Sclerotia +
Conidia
Infection in leaves, stem,
seedling, Flowers
Production of conidia
Symptom development
Secondary spread through
wind
Secondary
cycle
498

499. FavourableCondition-
Prolongedperiodsof freemoisture favourinfection
For conidial germination, 18 to 25℃temperature and
relativehumiditybetween93 to100 percentisoptimum.
499

500. Management-
Practicegoodsanitation.Removeanddestroyallinfected
plantpartsassoon astheyareobserved.
Avoid overhead watering. Water on foliage and flowers
fromoverheadirrigation,especiallyoncool,cloudydays,
promotesthedisease.Trytokeepbudsandflowersdry.
Water early in the day so the plants have enough time to
dryoffcompletely.
500

501. ▪Avoidovercrowding.Give adequatespacebetweenplants to allow for
good air circulation. The fungus thrives in areas that are cool and moist
and where plants are overcrowded.
▪Use fungicides. Depending upon the susceptibility of the plant to this
disease, spray every 10 days with a fungicide.
▪captan, chlorothalonil(Daconil),mancozeb, maneb,sulfur,and
thiophanate methyl .
▪Fungicides must be appliedin advanceof thediseaseasa protectant.
501

502. Thank
You
502