Agriculture Reference
In-Depth Information
CULTURAL PRACTICES
Propagation
Sexual
Mango seeds should be planted while still fresh, as they lose their viability
within a few weeks. The usual procedure is to eliminate the pulp from around
the seed by fermentation and washing, and superfi cially dry the seed in the
shade for a couple of days. Uniform germination can be achieved if the kernel
is removed from the hard endocarp or seed coat; this can be achieved by
using pruning shears to cut the edges and remove the seed. During sowing,
the concave part of the seed should face down and be buried about 4-5 cm
into sand or a sandy mix. This sandy medium allows easy extraction of the
seedlings with little damage to the roots when repotted. The germinated
seedlings are separated and transplanted singly into polyethylene bags (18 cm
(w) × 13 cm (d) × 30 cm (h)), and bags up to 45 cm in height help to avoid
early root deformation. The seedlings are grown under ~30% shade. The seeds
of polyembryonic cultivar produce several seedlings, some of which become
twisted together and have curved stems and roots, and should be discarded
and not transplanted into nursery bags. Monoembryonic seeds from
breeding
programmes can be planted directly into the polyethylene bags. Polyembryonic
cultivars, though they can be propagated by seed as they retain the parental
characteristics, are grafted to take advantage of the earlier production and
shorter, stockier trees, avoiding the juvenile characteristics of seedling trees.
Asexual
Cultivars are propagated vegetatively by such methods as cuttings, grafting,
budding or air-layering. Cutting propagation has been successfully achieved
using hardwood or semi-hardwood cuttings, or subterminal cuttings with
adult leaves being put under mist and bottom heat, and the cut surface treated
with auxin (Reuveni
et al.
, 1991). This method is justifi ed in cases of a scarcity
of monoembryonic rootstock material.
Seedlings can be grafted in 6-8 months if fertilized and irrigated regularly.
Grafting is usually some form of side or cleft graft, with the side-wedge method
also being frequently used. Splice grafting is occasionally used. Only a well-
matured terminal and the section below it should be used as scion wood,
immature wood often fails to graft. Terminal scions are preferred because
they will have no wound at the apex end of the scion piece. Budding methods
permit the use of much younger rootstocks. Buds may be prepared in advance
by removing the leaves of mature terminal wood. Removal of the leaves and
the apical bud destroys apical dominance and allows axillary buds to begin
to swell in 1-2 weeks. Air-layering and inarching are used in some areas to
generate experimental plants rapidly. However, these time-consuming methods
are appropriate when only a few plants are needed. Cultivars propagated by
