Wilt is a pernicious disease of guava in India. In India the disease was first recorded near Allahabad in 1935 . The infection was reported 15 -30 %. The disease is a serious threat to guava cultivation in U.P. In West Bengal it reduces the yield in affected orchard by 80% . The disease is also prevalent in Haryana Rajasthan , A.P , Punjab and M.P.The exact cause of the disease is still not fully understood but the pathogens viz. Fusarium oxysporum f. sp. psidii (Prasad, Mehta & Lal), Rhizoctonia spp. (Taub.) and various pathogens are reported by different workers may be the incitant of the disease. Survival and spread: Through movement of plants containing sick soil in virgin areas. Short distance spread is by water. Root injury predisposes wilt disease. It has forced uprooting of about 150 acre of guava orchard in Panjab and 300 acres in Haryana during 1971-81.

2. PERSENTATION ON
DISEASES OF GUAVA
PRESENTED BY
SUSHEEL KUMAR
Id. No. 48008
M.Sc. 3rd YEAR
VEG. SCIENCE

3. GUAVA WILT

4. OCCURRENCE AND
IMPORTANCE
 Wilt is a pernicious disease of guava in India.
In India the disease was first recorded near Allahabad in
1935 . The infection was reported 15 -30 %.
The disease is a serious threat to guava cultivation in U.P.
In West Bengal it reduces the yield in affected orchard by
80% .
The disease is also prevalent in Haryana Rajasthan , A.P ,
Punjab and M.P.
It has forced uprooting of about 150 acre of guava orchard
in Panjab and 300 acres in Haryana during 1971-81.

5. CAUSAL ORGANISM
 The exact cause of the disease is still not fully understood but
the pathogens viz. Fusarium oxysporum f. sp. psidii (Prasad,
Mehta & Lal), Rhizoctonia spp. (Taub.) and various pathogens
are reported by different workers may be the incitant of the
disease.
Survival and spread:
 Through movement of plants containing sick soil in virgin
areas.
 Short distance spread is by water.
 Root injury predisposes wilt disease.

6. CONTI…..
Favourable conditions:
 High rainfall during August/ September.
 Stagnation of water in guava field for long duration.
 Maximum and minimum temperature ranges 23-32 °C with
76% RH are conducive.
 Lack of timely application of suitable control measures.
 There is severe incidence of wilt in alkaline soils at pH ranging
from 7.5 to 9.0 or in lateritic soils at pH 6.5 .
 Guava seedlings are more susceptible to F. solani as well as F.
oxysporum f.sp. psidii than older plants of 3 years age.
 On the other hand researchers reported that F. solani could
infect guava plants from 1-month-old to more than 4 years old.

7. SYMPTOMS
The leaves shed of premature , fruit
size remain smaller, bare twig fail to
develop new leaves and flower dry
up.
 Browning and wilting of leaves
from tip.
Discolouration of stem and death
of branches and then the whole tree
dry up.
 The inner part of stem and root
upto cambium and vascular tissues
show a distinct discolouration.

8. DISEASE CYCLE

9. MANAGEMENT
 Proper sanitation.
 Soil solarization.
 Uprooted and burnt wilted plants.
 Severe pruning followed by a drench with .2 % Benlate
or Bavistine 4 times in a year.
 Injection guava plant with 0.1 % water soluble 8-
quinolinol sulphate may provide protection against wilt
for at least 1 year.
 Use of resistant and tolerant varieties like , Allahabad
Safeda , Dholka , Sindh etc.

10. ANTHRACNOSE

11. OCCURRENCE AND
IMPORTANCE
 Anthracnose is most common and important disease of guava
in India, patricularly in U.P. ,Punjab and Karnataka.
 It first reported from Saharanpur(U.P).
 The disease also occur in Thailand , Philippines ,Bangladesh
and Pakistan.
 It also cause serious postharvest rotting of guava fruits.

12. CAUSAL ORGANISM
Anthracnose is caused by Gloeosporium psidii,or colletotrichum psidii.
Survival and spread:
 Infection spreads by wind borne spores develop on dead leaves, twigs and
mummified fruits in the orchard.
 Dense canopy is congenial for germination of spores due to high moisture
condition.
 Movement of planting material through infected foliage.
 Transportation of fruits from high disease prone area.
Favourable conditions:
 Closer planting without canopy management
 The acervuli with pink spore masses are produced in moist weather on dead
twig and mumified fruits.
 Dew or rains encourages spore production and its dispersal around canopy.
 Temperature between 10 to 35oC with best 24 to 28oC.

13. SYMPTOMS
 Fruit and leaf infection is generally seen
during rainy season crop. Pin-head spots are
first seen on unripe fruits, which gradually
enlarge.
Spots are dark brown in colour, sunken,
circular and have minute black stromata in the
center of the lesion, which produce creamy
spore masses in moist weather.
Several spots coalesce to form bigger lesions
.
The infected area on unripe fruits become
corky and hardy, and often develops cracks in
case of severe infection.
Unopened buds and flowers are also affected
which cause their shedding.
On leaves, the fungus causes necrotic lesions
usually ashy grey and bear fruiting bodies at
the tip or on the margin .

14. DISEASE CYCLE

15. MANAGEMENT
 Three applications of Bordeaux mixture and Perenox (0.22
and 0.33%) after removal of dead twigs.
 Spray of copper oxychloride and cuperous oxide (.3%) at
weekly intervals effectively reduce the infection.
 Apply Carbendazim 1gm/litre during June-September.

16. FRUIT ROT

17. OCCURRENCE AND
IMPORTANCE
 Phytophthora fruit rot cause extensive damage to
rainy season crop of guava in Maharastra , Karnataka,
Rajasthan ,Panjab and Haryana.
 Sohni and Shridahar (1971) recorded 16.3 % loss to
the crop before harvest in Mysore.
 The post harvest loss are much higher.

18. CAUSAL ORGANISM
 Phytophthora nicotiana var. parasitica cause fruit rot of guava.
Survival and spread:
 Rain and the wind are conducive for spread.
 The pathogen produces a great number of sporangia and spores on the
surface of diseased tissues principally when the temperature is near
25°C and this is an important sources of inoculum in the development
of epidemics.
 Spores spread from the infected plant material or soil by rain splashes.
Favourable conditions:
 Cool, wet environmental conditions with high soil moisture favour
disease development.
 High humidity, temperature from 28-32oC (25 oC), poorly drained soils
and injuries are favourable for initiation of disease.
 Close plantation.

19. SYMPTOMS
The disease starts at blossom and stem
end or even anywhere on the surface of well
developed fruits.
The skin of the fruit below the whitish
cottony growth becomes a little soft, turns
light brown to dark .
 Young, small and unripe fruits are more
prone to infection. They become hard and
woody.
On leaves the disease starts as small
brown spots at margin or tip, spread fast
and affected the entire lamina.

20. DISEASE CYCLE

21. MANAGEMENT
 Soil solarisation .
 Destroy plant debris.
 Sprays of Bordeaux mixture , copper oxychloride (.2%) and
Dithane- Z- 78 (.2%) for control of guava fruit rot.
 Six spray of Dithane- Z- 78 (.2%) at one month interval from
June to November.