production technology

1. PAPAYA
Botanical name - Carica papaya
Family - Caricaceae

2. Chemical constituents in papaya fruits
• Moisture - 89.6
• Carbohydrate - 9.5
• Proteins - 0.5
• Fat - 0.1
• Calorific value - 4 ( in 100 grams)
• Minerals - 0.4
• Calcium - 0.01
• Iron (mg / 100 g) - 0.4
• Vitamins (mg / 100g) -
• Carotene (Vit. A)(IU / 100g) - 2020
• Thiamine (Vit B1) - 40
• Riboflavin (Vit B2) - 250
• Nicotinic acid - 0.2
• Ascorbic acid (Vit C ) - 46

3. BOTANY
• Polygamous
• Three types of flowers
• 1. Staminate ( Male )
• 2. Pistillate ( Female )
• 3. Hermaphrodite ( Bisexual )

4. INFLORESCENCE AND FLOWERS
• Male trees - Flowers are in clusters on long
branches 60-90cm
Individual male flower is tubular,
with ten stamens attached to the
corolla in two series.
• Female trees - Female flowers are on short 4-6cm
peduncles petals are separate.
• Hermaphrodite trees.
- There are numerous deviations, flower is
on short peduncle elongated pistil.
Petals are fused upto 2/3 of their length.
Ten stamens in two series of five.

6. Environmental influence of flowers
mainly temperature is responsible
• Stamen carpellopy is expressed under cool temperatures.
( in this case instead of 10 stamens there are only 5)
Reason - low temperatures below 13 * C.
• Excessive N & moisture
• Female sterility
Cause - Excessive high temperature, N deficiency &
moisture stress
• Hermaphrodite trees
• >32degree C High temperature – behaves like male
Low temperature – behaves like female
Very low temperature - carpellodic fruits.

7. Depending on the types
of flowers present on a
tree. Papayas are
classified into eight
categories.

8. Types of papaya flowers
Types Tree Flower Description
Staminate M M Typical unisexual flower on long
peduncles
Teratological M M Found on sex-reversing male tree,
Staminate with some degree of carpel
initiation and development, A number
of hair-like processes – vestigial
carpellate base
Reduced MF M Modified normal elongata flower
differs from staminate flowers
in having a thicker and stiffer corolla
tube, abortion of pistils and reduced
ovary size and number of carpels. More
frequent during warm periods and late
summer, and can last from 1 – 2 weeks
to 6 months, depending upon cultivar
and temperature.

9. Pure male plant ( M1rr m )

10. Sex reversing male ( M1Rr m )

11. Sex reversing male ( M1RR m)

12. Types of papaya flowers
Types Tree Flower Description
Elongata MF MF Elongata refers to the shape of the pistil
(normal type) terminating in fine stigmata lobes ;
develops into pyriform or cylindrical
fruit, five laterally fused carpels. Petals
fused two-thirds length.
Carpelloid MF F Transformation of the inner series of
Elongata stamens into carpel-like structure.
Numerous types with different number
of stamens becoming carpelloid and
degree of carpellody, from slight to
developing locales with functional
stigma. Fruit to varying degrees
misshaped.

13. Types of papaya flowers
Types Tree Flower Description
Pentandria MF F Normal hermaphrodite type, modified
unisexual pistillate flower, through
stepwise stamen transformation to
carpels, with loss of the original carpels.
Short corolla tube, only five stamens of
the outer whorl on long filaments
globose and furrowed pistill. From five
to ten carpels.
Carpelloid MF F The stamens of the outer whorl become
Pentandria carpelloid. Carpellodic forms in various
stage, especially under cool conditions.
All five stamens fully carpelloid and
fuse laterally, with abortion of original
carpels, flowers resemble pistillate
flowers- pseudo – pistillate.

14. Types of papaya flowers
Types Tree Flower Description
Pistillate F F Unisexual flowers larger
than MF flower, lack
stamens. Form stable and
unchanged by environment.

15. GENERAL DESCRIPTION
• Single erect stem may attain height upto 9 mtrs.
• Multiple branching only when growing tip is disturbed.
• After transplanting shoot growth is slow.
• Root growth is rapid in the initial stage.
• After 25 days of transplanting stem growth rate increases and goes upto 2mm
per day in circumference.
• Growth rate is depended on
• Nitrogen
• Phosphorus
• Irrigation
• Temperature
• Floral primordia is laid 50 – 70 days prior to anthesis at the rate of one flower
every three days.

16. Growth Rate of Root and stem
• The growth rate
of papaya root
and stem from
planting in the
field, showing
root growth-rate
reduction at the
start of
flowering and
shoot growth as
fruit mature.

17. LEAVES
• Rate of emergence 2-3 per week
• Cool season 2.4 leaves per week
• Warm season 3 leaves per week
• Length of leaves 60-90 cm

18. Growth & development
• Seed germination Two weeks
• Flowering starts after a fixed no. of leaves have
appeared.
• This varies from variety to variety from 24 to 49.

19. Pollination & Fruit set
• Female & hermaphrodite varieties
• There is no pollination problem.
• Pollination problem occurs when dioecious varieties
are planted with inadequate number of male plants.
• Ratio of male to female should be 1:10
• On hermaphrodite trees it is common for the
terminal flowers to set while the lateral flowers
abcise.
• Under favourable conditions one or two lateral
flowers also set.

20. FRUIT
• Fruits of females trees are spherical
• Fruits of hermaphrodite trees show diverse shapes normally elongated.
• Fruit size varies from 255 grams to 7 kgs, flesh thickness varies from
1.5 to 4 cms.
• Fruit cavity may be star shaped or round
- good variety small fruit cavity.
• Seedlessness
Seen on female plants when fruit is set in absence of pollens but
seedless fruits are small in size.
• Fruit Growth
Total period varies from 150 – 160 days
Fruit growth shows two major phases
1st
is 60 - 80 days after anthesis.
2nd
100 ~ 120 days.

21. Changes in Fruit
• Changes in
fruit starch
and total sugar
of developing
‘Solo’ papaya
fruit. Note the
dramatic
increase in
sugars during
the last phase
of fruit
development.

22. Fruit Growth Rate
• The increase
in fruit fresh
mass and the
mass for skin,
seeds and
mesocarp
during fruit
development.

23. Cultural Practices
• Propagation is done by seeds.
• Two methods
1. Direct sowing.
2. Transplanting.
Seed count 50 – 70 per gramme
Transplant Production
Depth of sowing – Twice the diameter of the seed.
Time of germination : 13 – 16 days.
Nursery bag size : 6” x 8”
Colour of bag – Black
Height of transplanting : 8” – 10”
Protection of nursery by insect proof net against - sucking pests
Use preventive chemicals for Ants and Damping off.
Nursery fertilization - 50 : 50 : 50
N : P : K

24. Field Preparation
Standard land preparation practices
1. Sub soiling.
2. Ploughing.
3. Discing.
4. Bed Preparation.
Pit Digging – 30 – 45 Cms in diameter.
30 – 45 Cms deep.
Fertilizers – Added to the pit.
Mixed with soil.

25. Spacing
• Depending upon the variety
• 40 ~ 70 sq ft. per plant is
required.

26. Transplanting
• Transplant at the same level as in nursery bag.
• Water liberally after planting, there should be
no air spaces.
• Transplanting at an angle of 45 degree leads
to fruiting at lower height (If leaf touches the
soil it can be removed.)

27. Response of Irrigation on fruit yield
• Relation
between yield
of marketable
fruit and the
water
application as
a fraction of
potential pan
evaporation.

28. Irrigation
• Crop factor
• Young tree - 0.3 ~ 0.4
• Upon flowering - 0.5 ~ 0.6
• Fruit set start - 0.8 ~ 0.9
• After 20 – 25 fruits - 1.10 ~ 1.30

29. Fertilization
Nutrient removal per ton
• Nitrogen - 1770 grams.
• Phosphate - 200 grams.
• Potash - 2120 grams.
• Calcium - 350 grams.
• Magnesium - 180 grams.
• Sulphur - 200 grams.

30. Relative Nutrient Requirement
• N - Very high
• P - Medium
• K - Medium
• Ca - Medium
• Mg - High
• S - Medium
• B - Low
• Cu - Medium
• Fe - High
• Mn - Medium
• Zn - Medium

31. Standard plant tissue analysis
• ( Petiole analysis )
• Fully grown leaf.
• N - 1.10 ~ 1.40%
• P - 0.15 ~ 0.18%
• K - 2.5 ~ 3.5%

32. Weed Management
• Hand weeding near the plants.
• Herbicide sprays in the other portion.
• Paraquat @ 1 Litre / acre.
• Glyphosate @ 1.5 Litre / acre.

33. Harvesting
• Small trees by hand.
• Tall trees by help of ladders or harvesting
aid.
• Labour efficiency for harvesting
• 360 ~ 450kg / in 8 hours
• Bruising of fruits should be avoided.

34. Labour requirement
• Nursery growing - 20 mandays
• Planting (without pit digging) - 20
• Weeding - 30
• Irrigation & Fertigation - 30
• Harvesting - 100
• Grading & Packing - 60
• Clearing of land - 50
• Miscellaneous - 50
-------------
360 mandays

35. Alternaria fruit spot
• Alternaria
fruit spot
on papaya.

36. Alternaria Fruit Spot
• Fungus infects drying leaf petioles & fruit
surface.
• Disease comes during dry environments.
• Control :
1. Sprays of chlorothalonil and mancozeb
2. Post harvest dip of fruits in hot water for 20
minutes at 48 degree C.

37. Anthracnose
• Typical chocolate spot lesion
caused by Colletotrichum
gloeosporioides.

38. Anthracnose
• Typical
anthracnose
lesion caused
by
Colletotrichum
gloeosporioides
with pinkish
orange spore
mass.

39. Anthracnose
• Major damage is done after harvest during long
distance transport and storage under low temperature.
• Disease of ripe and over ripe fruits.
• Favourable conditions
High temperature > 28degree C.
High humidity > 97 % R.H.
Free water is necessary for spore germination
Control
1. Protective fungicides at 14 or 28 days interval during
rainy season.
2. Post harvest - Hot water dip.

40. Cercospora Black Spot
• Cercospora black spot on
ripe Kapoho Solo papaya.

41. Cercospora Black Spot
• Spot Occurs on fruit and leaves.
• Fruits are susceptible from 5-6 weeks of age.
• Control protective fungicide sprays at 14-28
days interval.

42. Dry Rot
• Dry rot caused
by
Mycosphaerlla
sp. Is the most
common cause of
stem-end rot of
papayas in
Hawaii.

43. Dry Rot
• Symptoms post harvest stem end rot.
• Fungus survives and multiplied on dead leaves
and fallen fruits.
• Conditions for spread of fungus 100% R.H.
• Condition for infection – wounding of fruits
• Control
1. Fungicide sprays.
2. Hot water dip
3. Sanitation.

44. Poor Field Sanitation
• Field sanitation,
such as the
removal of
fallen fruit from
the field, is
essential to
minimize
disease build-
up, especially in
a fruit crop with
continuous
production,
such as papaya.

45. Fusarium Fruit Rot
• Fusarium
rot on a
papaya
fruit.

46. Fusarium Fruit Rot
• Causes lesions on fruits.
• Fruit drop.
• Seedling collar rot.
• Control :
Preventive fungicide sprays.
Hot water dip.

47. Phytophthora Fruit Rot & Root Rot
• Phytophthora
blight of papaya
fruits. Note
mycelium of
casual fungus,
Phytophthora
palmivora,
which covers
the fruits.

48. Phytophthora Fruit Rot & Root Rot
• Severe
damage to
papaya
trees
caused by
Phytophth
ora
palmivora.

49. Phytophthora Fruit Rot & Root Rot
• Root rot of
papaya
seedings
caused by
Phytophtho
ra
palmivora.

50. Phytophthora Fruit Rot & Root Rot
• Heavy fruit losses during rainy season severe
decline and death of papaya trees in poorly
drained areas.
• Fruits show water soaked lesions that exude
milky latex.
• Fruits shrivel and fall to the ground.
• Leaf fall.
• Cankers on stem.
• Trees become stunted.
• Death of tree.

51. Phytophthora Fruit Rot & Root Rot
• Critical stage 1st
three months after emergence.
• Yellowing of leaves.
• Premature defoliation.
• Death.
• As the plant passes this age it becomes resistant to
root rot.
• Control
1. Fruit rot – Protective mancozeb and basic copper
sulphate spray on fruit column.
2. Root rot – New soil used in planting pet ( Avoids
infection in susceptible stage ) < 3 months.
3. Proper drainage.
4. Mulching.

52. Powdery Mildew
• Predisposing factors
1. Low light.
2. High humidity.
3. Moderate temperature.
Symptoms
1. Defoliation of older leaves.
2. Stem and fruit lesions.
Control :
1. Wettable sulphur.
2. Systemic fungicides like thio phanate methyl
triademefon etc.

53. Rhizopus Soft Rot
• Rhizopus soft
rot of papaya
fruit .

54. Rhizopus Soft Rot
• Post harvest disease.
• Reasons :
Wounding of fruits.
High humidity and temperature during
transit.
Control :
1. Sanitation.
2. Proper handling.
3. Heat treatment of fruits.
4. Preventive field fungicide sprays.

55. Papaya ringspot virus.
• Characteristic
ring spots on
papaya fruit
caused by
papaya ringspot
virus.

56. Papaya ringspot virus
• Mosaic
symptoms on
papaya
foliage
caused by
papaya
ringspot
virus.

57. Papaya ringspot virus
• Oily streak pattern on
papaya stem caused by
papaya ringspot virus.

58. Papaya ringspot virus
• Shoestring
symptom on
papaya foliage
caused by
papaya
ringspot virus.

59. Papaya ringspot virus
• Secondary
spread of
papaya ringspot
can devastate an
orchard.

60. VIRAL DISEASES
Papaya Ringspot
Casual Agent - Papaya ring spot virus
Host range - Caricaceae, Cucurbitaceae,
Chenopodiaceae
Synonyms - Papaya mosaic
Papaya distortion ring spot
Symptoms
On fruits - Dark green slightly sunken
rings uneven bumps on fruits
rings becomes less distinct as
fruits ripens.
On leaf - Yellow mosaic on leaf, shoestring
appearance.
On stem - Oily streaks on stem.

61. VIRAL DISEASES
Papaya Ringspot
• Symptoms appear 3 weeks after inoculation
• Spread by – Aphids ( Non persistent manner )
• - not seed transmitted.
• Control
1. Roguing.
2. Clean cultivation.
3. Protection of nursery.
4. Interplanting with non host crop – corn.
5. Cross protection.
6. Crop rotation.

62. Root-knot nematodes.
• Galls on roots of
papaya caused by
root-knot
nematodes.

63. Nematodes
Root knot nematodes
• Crop rotation.
• Solarization with plastic mulch.
• Nematicide.

64. Carpellodic fruit
• Papaya fruit column with
numerous carpellodic fruit.

65. Carpellodic fruit
• Stamen carpellody
induced by
environmental
conditions
(temperature, water
strees, fertilization)
on young
hermaphrodite trees
significantly alters
fruit shape. The
mild forms are
sometimes referred
to as ‘cat face’.

66. Carpellody
• Papaya fruit column with
numerous carpellodic
fruit.

67. Carpellody
Hermaphrodite varieties when exposed to
1. Low temperatures.
2. High nitrogen.
3. High moisture.
The male parts ( stamens ) develop into carpel
like structure and form fruits which are
severly deformed.

68. Boron deficiency.
• Symptoms of
bumpy fruit
caused by boron
deficiency.

69. Bumpy Fruit
Cause - Boron deficiency
• Petiole analysis - < 20 ppm shows bumpy
fruit normal level > 25 ppm
• Control
- 0.25% Boron spray on foliage
or apply 1kg. Elemental
boron to soil / acre.

70. Fruit - fly
• Fruit-fly larvae damage
of ripe papaya. This
group of insects attacks
many tropical fruit and
may require post harvest
disinfestation treatments
before export to some
markets.

71. Insect Disinfestation
• Postharvest insect
disinfestation
requires treatment
in chambers
similar to the one
shown, in which
the fruit is
subjected to
temperatures up
to 50c at high
relative humidity
for 6-8h.