Page 12 - Vol.37-No.8

CROP PROTECTION

PAPAYA IS A TRULY TROPICAL FRUIT

ing) and non-branched stems.
It supports a crown of leaves, the low-
er ones falling off and leaving large
orbicular scars on the stem. Papaya
leaves are medium to large in size,
averaging 50-70 cm in diameter and
18-90 cm in length. Leaves are broad,
flat and deeply palmately-lobed. The
green leaves are rough to touch, thin,
pliable and with prominent yellow
leaf veins spreading throughout the
5-9 lobes of the leaf.
DR. TERRY MABBETT
Papaya flowers are tubular and trum- Flowers and fruit are borne in the axils
Increasing trade and travel has pet-shaped, white blossoms which of the large leaves with thick and rigid
brought the world’s human popula- emerge from the axil of the papaya leaf stalks (Picture Dr Terry Mabbett)
tion and its fruit closer together. Exotic leaf with a thick and rigid leaf stalk
fruits of the tropics that were once only (petiole). Flowers grow from 2.5 - 5 varieties currently grown throughout
seen in magazines and movies now fill cm in length and are waxy and highly the tropics is Haiwaiin Sunrise with
the supermarket shelves of European perfumed. And because of their bright- small fruit (500 g in weight), red-or-
countries. white colour are frequently used as gar- ange flesh and a hint of strawberry
Papaya (Spanish) or paw paw (Eng- nishes for food dishes and as festive flavour; and the Guinea Gold variety
lish) is one such example. With truly decorations. of papaya from Western Australia with
tropical origins papaya (Carica papaya) Dioecious varieties (having male and its rich, yellow-coloured flesh. When
is the only commercially important spe- female flowers on separate plants) are ripe, fruits of the papaya will generally
cies of a large plant family (Caricaceae) by necessity enforced cross-pollina- contain about 10 per cent sugar, virtu-
with origins in the hot steamy jungles tors. Gynodioecious varieties (having ally no starch and provide consumers
of Central and South America. hermaphrodite and female trees) can with a rich source of vitamins and es-
Spaniards first took papaya to Asia be self-pollinators or cross-pollina- pecially A, B1, B2 and C.
and established it as a crop in the tors. Over recent years many hybrid Papaya is a true tropical crop and
varieties have been bred. Transgenic
Philippines. The ‘tree’ which is high- varieties have been developed using as such is very sensitive to growing
ly sensitive to temperature, humidity genetic modification technology. conditions. Optimal temperature for
and soil water relations, is now grown growth of papaya is around 25°C with
throughout the world wherever climate Fruits are usually ‘pear’ or ‘bomb’ 1500 mm of well distributed rainfall.
and soil type and condition allows. The shaped, traditionally large, hollow, Papaya will not tolerate flooding and
Spanish name papaya which is univer- heavy (0.5-2.0 kg) and green, turning waterlogging, even for short periods
sally used for the fruit, except in Cuba yellow/orange as they mature and rip- and sub-zero temperatures or high
where fruit are called ‘fruita bomba’ en. The edible flesh, which represents winds. Papaya prefers a sandy and
to distinguish from papaya which has part of the mesocarp and the endo- very well-drained soil.
impolite suggestions. carp, is yellow to orange-red in colour Propagation is by seed sown in sandy
Though commonly referred to as a depending on the variety. The hollow beds or directly into polybags using
tree, the papaya plant is non-woody centre (central cavity) contains numer- a growing mix of 50 % sand and 25%
ous dark-coloured seeds similar in size
and more resembles an extra tall kale each of organic manure and topsoil.
plant with hard but only soft-woody and shape to peppercorns, which is Seeds germinate after two weeks and
seed of the black pepper vine. Fresh
stems. Papaya is a fast growing plant seedlings are transplanted into the field
with hollow, lactiferous (latex produc- papaya seed is moist, shiny and smooth after two to three months at a spacing
due to an outer layer of mucilage but of 2.5 m x 3.0 m. The planting hole for
shrivels on drying. papaya is 30 cm x 30 cm x 30 cm and
When I first wrote about papaya some
two decades ago universally-grown
varieties included:
• Suban 6 - with firm, yellow flesh but
a relatively low sugar content
• Sitiwan - firm red flesh but bland
tasting and therefore used mostly for
processing
• Exotica - popular for eating fresh
due to its attractive red coloured flesh
with a high sugar content
These varieties are still grown, but a
booming export trade which has devel-
Papaya is a fast-growing plant oped since then demands smaller and
reaching 3 to 4 m in height and bearing more compact fruit with good skin and First signs of ripening are a yellowing
of the fruit skin
a crown of large leaves at the apex of flesh colour, as well as fine flavour and (Picture Dr Terry Mabbett)
the plant (Picture Dr Terry Mabbett) high sweetness. Among the countless
10 Vol. 37 No. 8