Agriculture Reference
In-Depth Information
Fig. 12.8.
Effect of planting density on fruit weight (a) and fruit yield (b); data are
for 'Queen' grown in Ghana, 'Singapore Spanish' grown in Malaysia and 'Smooth
Cayenne' grown in Queensland and Swaziland (from Hepton, 2003).
of the water-storage tissue of the youngest, physiologically mature leaf
(D-leaf) and by the percentage of white root tips visible on the roots in the soil
(Sanford, 1962).
Irrigation allows year-round planting, allows plants to attain a desirable
plant size for forced fl ower initiation at scheduled times of the year and for
harvesting on a fi rm schedule, allows the use of soils with poor water retention
and allows fertilizing even during the dry season (Fig. 12.7). Weed problems
are, however, increased by overhead irrigation. Sprinkler delivery systems,
including a self-propelled boom sprayer, have been used. Drip irrigation has
replaced other methods of irrigation in most fi elds in Hawaii, with one tubing
orifi ce for every two plants. The quantity of water applied is low compared
with most other crops, typically being in the range of 1.5 cm/ha/week. Drip
irrigation allows fertilizers and nematicides to be applied at the root system
after planting with increased ei ciency and safety, and yields are increased.
