thrives well in tropical climate. The occurrence of
low temperature and frost limits its cultivation. The
optimum temperature for the growth and development of
papaya is 22-26ºC. In Kerala, the limiting factors
for commercial cultivation are high rainfall and severe
drought in summer. However, this is best suited as a
homestead fruit crop. The papaya prefers a rich, well-drained
soil. It will not tolerate waterlogging around the trunk.
Honey Dew, Coorg Honey Dew, Solo, Co-1, Co-2, Co-4,
Pusa Nanha, Pusa Giant
Co-2 and Co-5 are suitable for papain extraction.
Papaya is propagated almost entirely by seeds. The
best time for raising papaya seedlings is from February
to March. The seeds are sown in raised seedbeds of
2 x 1 m made 15 cm above the ground level or in polythene
bags. A mixture of sand, leaf mould and dried FYM
is spread over the seedbed. The seeds are sown 2-3
cm deep at a distance of 5 cm in rows 15 cm apart.
To raise seedlings for planting in a hectare, 250
g seeds are required. Seedbeds should be watered daily,
if there is no rain.
seedlings raised in polythene bags can stand transplanting
better than that raised in seedbeds. Polythene bags
of 20 x 15 cm size and 150 gauge thickness are used
as containers. They are filled with a mixture of FYM,
soil and sand in equal proportions.
seeds are sown in each bag and after germination,
only one seedling is retained.
Vegetative propagation by mound layering is also possible.
Two month old seedlings are transplanted in the main
field in May-June at a spacing of 2 x 2 m. Pits of
size 50 x 50 x 50 cm are taken and filled with topsoil.
Male plants are removed as soon as they flower and
the female and hermaphrodite plants are retained.
In pure female plantations, one male plant is retained
for every 10 female plants. Seedlings are shaded to
protect them from excessive sunlight until they establish.
In hermaphrodite or monoecious types male plants may
not be required.
Intercultivation and intercropping
Keep the papaya plot free of weeds. Two hand-diggings,
one in the beginning of the rainy season and another
in January-February are necessary. When papaya is
grown as the main crop, vegetables can be profitably
cultivated as intercrop for about six months from
planting of papaya seedlings.
The crop should be irrigated in summer. The ring system
of irrigation is better for papaya than the basin system
because the ring system prevents irrigation water coming
into contact with the stem, thus preventing collar rot.
It causes rotting of seedlings in the nursery. This
can be prevented by sterilizing the soil of the seedbed
with 2.5% formaldehyde solution and covering it for
48 hours with newspapers or polythene sheets. This treatment
is given 15 days before sowing.
rot or stem rot
Waterlogging and bad drainage are the chief contributing
factors. Application of Bordeaux paste on the stem and
soil drenching with Bordeaux mixture are control measures.
It causes premature fruit fall and leaf fall. To control,
spray Bordeaux mixture 1%.
Papaya mosaic and papaya leaf curl are two serious virus
diseases of papaya. Remove the affected plants and burn
seedlings flower and set fruit within 3-5 months after
transplanting. The number of fruits harvested per tree
per year varies from 25 to 30. Fruits showing streaks
of yellow colour are harvested. Although papaya trees
bear flowers and fruits continuously for many years,
it is not economical to retain the trees after 2.5 to
Papain is an active enzyme present in the latex or milky
secretion of papaya plants and immature fruits. Half
to three-fourth matured fruits (about 70 to 100 days
from fruit set) are preferred for papain extraction.
Tapping of fruits can be done early in the morning by
giving longitudinal skin-depth incisions (0.3 cm) on
the surface of the fruits from the stalk end to tip.
Stainless steel blades or knives or bamboo splinters
are used for incising papaya fruits. The milky latex
is collected in arecanut spathes or aluminium or glass
vessels. The incisions are repeated in two or three
subsequent occasions at 3 to 4 days intervals. The latex
collected in this way is dried in the sun or in an artificial
drier at 50-55ºC. A small quantity of potassium
metabisulphite is added to the liquid latex to extend
the storage life of papain. The dried latex can be stored
in airtight polythene or glass containers for a period
of six months. Tapped fruits are equally tasty as untapped
fruits, although impaired in appearance.