Agriculture Reference
In-Depth Information
suggested (Py
et al.
, 1987): small crowns 100-200 g and medium crowns
200-300 g, and slips or suckers small 200-300 g, medium 300-400 g and
large 400-600 g.
Spacing
Plant spacing or density af ects pineapple average fruit weight and yield per
unit area (Fig. 12.8). Plant density and other cultural practices for 'Smooth
Cayenne' are directed towards the production of a fruit size appropriate to the
principal use: the fresh fruit markets or processing. Spacing is also dependent
upon cultivar. Cultivars of the Spanish group produce smaller plants but have
spiny leaves, so wider spacing is used than for smooth-leaved cultivars (Fig.
12.8). On small farms, growers may use a single-row system with relatively
wide spacing between plants and between rows, giving plant densities of
15,000-25,000 plants/ha. In commercial plantings, a double-row system
has been widely adopted, although three- and four-row systems also are fairly
common. Multiple-row systems allow for increased planting density but may
make harvesting operations more dii cult and require good management to
assure plant requirements are met. In the conventional two-row bed system,
various spacing regimes are employed to achieve desired plant densities. In
areas where plastic mulch is used, changes in bed width are limited by the
width of mulch used. The spacing between plants in a row should not be less
than ~20 cm, and spacing between rows in a two-row system would be about
35 cm, with between 90 and 120 cm from bed centre to bed centre. Planting
densities typically range from 60,000 to 80,000 for 'Smooth Cayenne' and
hybrids with similar growth habit (Fig. 12.8). When plants of the same size
are forced, average fruit size decreases linearly as planting density increases,
with the extent of the decrease being determined by cultivar and environment
(Hepton, 2003). Planting densities as high as 75,000 plants/ha are used
where smaller fruits are desired. There is a fruit size decrease of about 45 g for
each population increase of about 2500 plants/ha.
Irrigation
The pineapple has a low water requirement and can survive long periods
of water stress under natural conditions. However, under non-irrigated
conditions yields are low, with poor-quality fruit of unacceptable size.
Irrigation of pineapple in the Ivory Coast increased yields by 14-22 t/ha,
with a cost equivalent to a yield of 5 t/h. The potential evapotranspiration
of pineapple can reach 4.5 mm per day and a soil's water-holding capacity
rarely exceeds 100 mm, so without rains, the water supply will be exhausted
within 3 or 4 weeks. Water defi cits can be indexed by the relative thickness
