Agriculture Reference
In-Depth Information
Fig. 8.5.
Effect of the amount of unwanted sucker growth of 'Williams' banana
before removal, on remaining sucker (follower) bunch mass, annual yield in the
fi
rst ratoon crop and the crop cycle duration between the
fi
rst and second ratoon.
Unwanted suckers were removed when they were 30 cm, 50 cm and 80 cm high,
leaving one following sucker per plant mat. The leaf area of the 80 cm sucker was
39 times greater than the 30 cm sucker (redrawn from Robinson and Nel, 1990).
comes at the side of the original plant; therefore care has to be taken that all
plants 'walk' in the same direction by carefully selecting the ratoon suckers
in order to keep the original distances between plants. Normally a machete is
used for this operation and care should be taken to disinfect it before every new
plant, to avoid transmission of bacterial diseases such as 'Moko'.
Removal of dead leaves is practised to reduce disease spread and to prevent
senescent leaves from hanging over suckers and reducing light and to prevent
fruit scarring. At least six to eight healthy leaves should remain on the plant
at fl owering to ensure maximum bunch development (Fig. 8.3). Plants with
severe leaf removal or damage (e.g. as a result of insect feeding) have reduced
bunch weights. The green life of the harvested banana is also reduced by
leaf loss.
Fertilization
Regular fertilization practices are followed on large commercial plantations
(15% of total world production) to maintain optimum productivity, while
in the less-intensively cultivated plantation less supplementary fertilization
occurs (Martin-Prevel, 1990). Defi ciency symptoms have been described for
leaf blade and petioles. Mineral analysis of banana plants has been used and
