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Propagation and Layout
5.1 Propagation
The papaya plants are propagated through asexual as well as sexual methods. In the
case of asexual method, air-layering, cuttings and budding have been successfully
practiced on a limited scale.
5.1.1 Air Layering
Air layering reproduces the characteristics of a preferred strain. All offshoots except
the lowest one are girdled and layered after the parent plant has produced the first
crop of fruits. Later, when the parent has grown too tall for convenient harvesting,
the top is cut off and new buds in the crown are pricked off until offshoots from
the trunk appear and develop over a period of 4–6 weeks. These are layered and
removed and the trunk is cut off above the originally retained lowest sprout, which is
then allowed to grow as the main stem. Thereafter, the layering of offshoots may be
continued until the plant is exhausted. However, the aforementioned method is not
feasible at a commercial scale due to the lower success rate.
5.1.2 Softwood Cuttings
Softwood cuttings made in midsummer (May and June) rooted quickly and fruited
well. Terminal portions of the shoot should not be used unless the growth has
matured and hardened. The cuttings can be cut into 10–15 cm (4–6′′) length, and the
leaves should be removed from the lower third of each cutting. Rooting hormones
may be used to hasten rooting (Crocker 1994). Cuttings can be inserted into a rooting
medium containing a 1:1 mixture of perlite and peat or other suitable materials such
as vermiculite or sand. The medium should be well-drained and sterile. Cuttings
taken in winters and spring are slow and deficient in root formation. Once rooted, the
cuttings are planted in plastic bags and kept under mist for 10 days, and then put in a
shade house for hardening before setting finally in the field. The longer (60–90 cm)
cuttings are rooted more readily than smaller cuttings in the rainy season and they
began fruiting in a few months very close to the ground. Cuttings are used for spe-
cific cultivars with parthenocarpic fruit (Bose and Mitra 1990). Rooting of cuttings
is practiced in South Africa, especially to eliminate variability in certain clones so
that their performance can be more accurately compared in evaluation studies.
5.1.3 Budding
Both forkert and chip methods of budding have proved satisfactory in Trinidad.
However, it is reported that a vegetatively propagated selected strain deteriorates