Changes

*''Bromelia comosa'' L. (1754), *''Ananas sativus'' (Lindley) Schultes f. (1830).

*Pineapple, ananas (En). *Ananas, pain de sucre (Fr)

*Perennial or biennial herb, 50-150 cm tall. *Leaves sword-shaped, up to 1 m or more long, 5-8 cm wide, margin spiny or almost entire, top ending in a fine point, fleshy, fibrous, grooved on upper surface, arranged in a close spiral, clasping the main axis at their base. *Inflorescence compact with numerous (up to 200) reddish-purple sessile flowers, each subtended by a pointed bract; sepals 3, short, fleshy; petals 3, forming a tube enclosing 6 stamens and a narrow style with 3-branched stigma. *Fruit a coenocarpium formed by an extensive thickening of the axis of the inflorescence and by the fusion of the small berry-like individual fruits; the hard rind of the fruit is formed by the persistent sepals and floral bracts, which more or less fuse; on average the fruit is cylindrical, about 20 cm long and 14 cm in diameter, weighing 1-2.5 kg; the fruit is surmounted by a rosette of short, stiff spirally arranged leaves, called the "crown"; flesh pale to golden yellow, usually seedless. Besides the "crown", also "slips" (shoots growing on the stem below the fruit) and "suckers" (shoots growing in leaf axils lower down the stem) are formed, which can be used for vegetative propagation.

In a suitable tropical climate the growth rate of the crop mainly depends on a steady moisture supply to the shallow root zone. Growth stagnates when moisture is lacking and excessive wetness invites foot rot. A range of growing techniques is employed to maintain moderate moisture levels: excellent drainage, if necessary helped by planting on raised beds, careful weed control, a polythene mulch over each row. Weeding a pineapple plot is not easy, but experiments in Malaysia have shown that weeds can reduce yield by as much as 42% in a new planting and 21% in a ratoon crop. This also depends on the weed species. Lalang ( ''Imperata cylindrica'' (L.) Beauv.) physically damages the pineapple plants with its underground rhizomes, and once it has gained a foothold, it can only be eradicated by killing the pineapple plants as well. The other noxious weed is nut grass ( ''Cyperus rotundus'' L.). Systemic herbicides are recommended for the control of these weeds. Bromacil can be used as a pre-emergence herbicide against nut grass. Depending on the weed flora, other pre- and post-emergence herbicides are used too.

The importance of fertilizers, especially nitrogen and potassium, in pineapple culture is well known. Nitrogen is required for vigorous plant growth but not when flower induction is contemplated because vigorous growth reduces flowering response. Phosphorus is needed during the first few months of growth while potassium is needed for fruit development. In the nutrient-deficient peat soils of Malaysia the recommended rates are 14 g N, 0.7 g P₂O₅and 23 g K₂O per plant, given as a broadcast three months after planting and two foliar sprays at 6 and 9 months. For ratoon crops, two-thirds of the above levels are applied per year. In Thailand where the crop is grown on sandy loam, the rates are 9 g N, 2.4 g P₂O₅and 7 g K₂O per plant for a plant crop. This is applied as one basal dressing, two leaf axil dressings, five foliar sprays and two urea applications, the latter combined with the flower induction treatments. The rates for the first ratoon crop are 6.5 g N and 6.3 g K₂O per plant.

One of the most serious diseases of "Singapore Spanish" and "Masmerah", seen only in Malaysia, is fruit collapse. The causal bacterium, ''Erwinia chrysanthemi'' , attacks the fruit a few weeks before maturity when it suddenly exudes copious fluid and bubbles of gas. There is no effective direct control, but spraying heptachlor on the ground at the time of flowering and 2 weeks later controls the ants which spread the bacteria. Diseased fruits need to be removed and destroyed elsewhere to reduce the population of the bacteria in the field. The pathogen also causes bacterial heart rot when it infects the tender bases of young leaves of 3-6 month old plants. The rot can cause serious losses and is characterized by its putrefying odour. The Cayenne and Queen pineapple appear to be resistant to this bacterium. In the Philippines and Thailand, heart rot is caused by the fungi ''Phytophthora cinnamomi'' and ''P. parasitica'' respectively. Marbling disease of the fruit, caused by ''Erwinia ananas'' , appears to be the most serious problem in Thailand. It is hard to identify the disease and there is no effective control apart from lowering the amount of inoculum by sanitation. Other diseases of the pineapple fruit include leathery pocket, fruitlet core rot, interfruitlet corking, soft rot and yeasty rot.

The mealybug ( ''Dysmicoccus brevipes'' ) is the most serious pest. The insect is common in the tropics and causes wilt of "Smooth Cayenne" and "Masmerah"; "Singapore Spanish" shows some resistance. Infected plants become yellowish-red to bright red at the leaf tips, this colouration spreading down the leaf with time. Soon other leaves turn colour and also show signs of wilting. Severely infested plants become stunted and produce small fruits. The mealybugs are found at the base of leaves, moving on to healthy plants once their host starts to wilt. Control of the mealybugs involves control of the ants which are responsible for their spread. Spraying or dipping the planting material using diazinon or malathion helps to control the wilt.

In Malaysia, fruits left to rot in the field as well as the large amount of fruit peel at canneries attract large populations of the beetle ''Carpophilus foveicollis'' , which find the over-ripe fruit an ideal breeding ground. These beetles are a nuisance, as they may accidentally be canned with the fruit.

*Y.C. Wee & M.L. Charuphant Thongtham