Pineapples: Optimum Growth Areas (Rainfall Requirements)

The pineapple, i.e. Ananas comosus is a frost sensitive tropical and subtropical plant. Pineapples can grow well under a wide range of rainfall from MAP 600 - 1 200 mm (Smith, 1998). However, irrigation is necessary when MAP is < 500 mm or when consecutive months of low rainfall occur. Daily mean temperatures around 23 – 24 degree Celsius are considered optimum for both acid and sugar content of pineapples. South Africa accounts for 6 percent of the world`s pineapple production in a market dominated by Thailand, Indonesia, the Phillipines and Kenya (SA Yearbook, 2005). Of the 6 350 ha planted to pineapple in South Africa, 69 percent is in the Eastern Cape and 30 percent in KwaZulu-Natal (Statistics SA, 2002). Two varieties are grown, viz. the smoother, larger and juicier Cayenne and the smaller, but sweeter Queen variety, with production shifting more and more towards the Cayenne variety. In South Africa pineapples flower within 14 - 20 months of planting, with summer fruit in the Eastern Cape taking 5 months to mature and winter fruit up to 7 months, implying that the plant crop is harvested at 18 - 24 months (Bathurst, 2005).

For pineapple production potential, precipitation is evaluated as follows: Monthly precipitation is divided by 10, with any monthly amount in excess of 100 mm scoring 10. The largest possible annual precipitation score would thus be 120, areas with MAP less than 500 mm are considered unsuitable for pineapple production, except under irrigation, areas with more than 3 consecutive months less than 15 mm or 4 consecutive months less than 25 mm or 5 consecutive months less than 40 mm precipitation per month are also considered unsuitable without supplementary irrigation.