PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

The study was carried out to determine the most effective, efficient, and profitable combination of fertilizer regime and pineapple residue management practice for pineapple grown on tropical peat. Three residue management practices, namely; (i) In situ decomposition of pineapple residue without any disturbance (R1), (ii) Stacking of pineapple residue slashed and raked from 0.6 m x 10 m beds into 0.9 x 10 m beds (R2), and (iii) In situ burning of pineapple residue (R3) were used in combination with three fertilizer regimes; (i) application of P and K at the 65th, 135th, 191st, and 233rd days after planting (F1), (ii) application of P and K at the 65th, 135th, and 191st days after planting (F2), and (iii) application of P and K at the 65th, 135th, and 191st days after planting but sharing fertilizer amount of the 233rd day between the 135th and 191st days (F3). The effect of the three residue management practices on P and K uptake as well as fruit yield was not significant. Similar observation was made for the three fertilizer regimes. In terms of cost, R1 was the cheapest residue management practice with R3 being the most expensive practice. F2 emerged the cheapest fertilizer regime while F1 was the most expensive regime. The most cost effective treatment combination was R1F2. Burning, stacking of pineapple residue in rows or leaving pineapple residue to decompose in situ did not improve K and P uptake as well as fruit yield. The application of K (188 kg/ha) and P (7 kg/ha) fertilizers at 233rd day after planting is not necessary and by omitting it the practice could save as much as RM 187.98/ha. The application of muriate of potash and China phosphate rock at the 65th, 135th, and 191st days (F2) under in situ decomposition of pineapple residue (R1) looks promising in terms of the cost effectiveness.