Agriculture Reference
In-Depth Information
has few fi ngers (fruit) and the rest of the nodes have non-functional pistils.
The infl oresence stem (rachis) is cut below the false hand, where a fi nger is
left attached to maintain a connection with the plant circulatory system and
avoid rachis rotting. The detached rachis removes the male fl owers. In plants
with no false hands at the time of fruit thinning, a fi nger will be left in the last
hand.
The 10 cm female fl owers of cv. 'Cavendish' have an inferior ovary of
three united carpels with a short perianth. The perianth consists of fi ve fused
and one free segment, forming a tube around the style and sterile androecium
and three-lobed stigma. Male 'Cavendish' fl owers are 6 cm long with fi ve
stamens, which rarely bear fertile pollen.
Pollination and fruit set
Natural pollination
The fruit develops parthenocarpically. The ovules shrivel early and are
recognized as brown specks in the mature fruit along the axial placenta (Fig.
8.2). Very infrequently, seeds are found in mature fruit of edible cultivars,
especially those with a 'B' genome. The 'Cavendish' group has absolute female
sterility with few viable pollen. The 'Gros Michel' (AAA) dessert banana
produces seed once in a while and therefore is used as the female parent in
many crosses. 'Pisang Awak' (ABB) can sometimes be very seedy if pollen-
bearing diploids are growing nearby.
Floral induction and fruit set
There are no external symptoms of the start of infl orescence development.
The fl owering stimulus is unknown. Externally, it is not temperature or
photoperiodism, and internally it is not the number of leaves developed,
as the number of leaves is more or less fi xed, depending on cultivars and
environment.
Fruit morphology
The fruit, although it develops from an inferior ovary, is a berry. The exocarp
is made up of the epidermis and the aerenchyma layer, with the fl esh being
the mesocarp (Fig. 8.2). The endocarp is composed of a thin lining next to
the ovarian cavity. The axial placenta has numerous airspaces and ventral
vascular bundles.
Each node of the rachis has a double row of fl owers, forming a cluster
of fruit that is commercially called a 'hand', with the individual fruit called a
'fi nger'. 'Cavendish' bananas can have 16 hands per bunch, with up to about
30 fi ngers per hand, and the bunch can weigh up to 70 kg. There are many
