Pineapple is one of the most important commercial fruits in the world. In Bangladesh it is called "Swarnakumari" for its beauty, and it is loved for its attractive fragrance and sweet-sour taste. Bangladesh grows pineapple on 15,000-20,000 hectares a year, producing about 150,000-200,000 tonnes of fruit.

Every year pineapple growers and traders suffer heavy losses from poor care and from disease and pest attacks, and during storage, processing, transport and marketing once the fruit ripens. The solutions are set out below for farmers and students of agricultural science.

Symptoms: water-soaked spots appear on the fruit, which later turn yellow and then dark brown and blackish. The tissue of the affected part softens and rots. Infected ripe fruit gives off a characteristic smell. If the leaves are infected, the whole plant turns black and rots.

Control: (1) Keep the orchard clean. (2) Use suckers of disease-resistant varieties as planting material. (3) Drying suckers in mild sunlight for two hours before planting lowers the risk of the disease. (4) Before packing harvested pineapples, disinfect the baskets with 3% formalin. (5) Dip the cut base of the fruit in a 10% benzoic acid solution.

This disease is caused by a fungus called Phytophthora parasitica.

Symptoms: the leaves first turn yellow and then brown. The base of the stem and the roots turn black and begin to rot. Eventually the whole plant dies.

Control: (1) Keep the orchard clean and tidy. (2) Grow disease-resistant varieties. (3) Make sure water does not collect in the orchard. (4) To prevent the disease, dip seedlings in Bordeaux mixture solution at a ratio of 4:4:50 before planting.

Damage: the insect sucks sap from the leaves, stems and fruit, causing wounds. If it attacks the roots or the joint of stem and root, the plant wilts. Infested fruit rots. A virus enters through the affected area and causes Ananas wilt.

Control: (1) Grow resistant varieties such as Queen, Pernambuco and Spanish. (2) After harvesting the fruit, burn the dry leaves and debris. (3) Spray Malathion 57 EC mixed at 8 cc in 2.5 litres of water.

Source: Staff Correspondent. First published in Bengali on The Agro News.