Abstract
Long-term records from the palm oil mill at Pamol Estates (Sabah) Sdn Bhd (Pamol Sabah) showed that OER (oil extraction rate) remained fairly constant but KER (kernel extraction rate) steadily declined from 1982, with the rate of decline worsening from 1990. In the more recent shorter term, there was a slight decline in OER from 1992 to 1994, and a drastic drop in KER in 1994. Data from 8 other mills in Sabah showed similar trends during the same period. The Sandakan mills suffered the worst drops in KER in 1994. Comprehensive analysis was not attempted to explain the trends, but possible factors which may partly account for the observed OER decline included increased proportions of purchased and young mature fruits in the total crop milled. The drop in KER in 1994, especially in the Sandakan mills, may have been a result of poor fruit set in the young mature crop. At Pamol Sabah, this was a major problem made worse by exceptionally high rainfall. There was a seasonal trend at Pamol Sabah and several other mills, with low KER tending to occur each year between May and Aug. This seasonal problem was estimated to cost RM 300 000 annually at Pamol Sabah, from losses in kernels and bunch weight. Pollination studies initiated at Pamol Sabah in December 1993 indicated that there may be a seasonal trend in the population of Elaeidobius kamerunicus, the pollinating weevil, which is closely related to male inflorescence density. High rainfall may also affect pollination by reducing weevil activity and overall viability of available pollen. Assisted pollination gives good fruit set during the months when natural pollination is poor. Severe pruning to induce male inflorescence production is being tested as a less labour intensive alternative to improve fruit set.Long-term records from the palm oil mill at Pamol Estates (Sabah) Sdn Bhd (Pamol Sabah) showed that OER (oil extraction rate) remained fairly constant but KER (kernel extraction rate) steadily declined from 1982, with the rate of decline worsening from 1990. In the more recent shorter term, there was a slight decline in OER from 1992 to 1994, and a drastic drop in KER in 1994. Data from 8 other mills in Sabah showed similar trends during the same period. The Sandakan mills suffered the worst drops in KER in 1994. Comprehensive analysis was not attempted to explain the trends, but possible factors which may partly account for the observed OER decline included increased proportions of purchased and young mature fruits in the total crop milled. The drop in KER in 1994, especially in the Sandakan mills, may have been a result of poor fruit set in the young mature crop. At Pamol Sabah, this was a major problem made worse by exceptionally high rainfall. There was a seasonal trend at Pamol Sabah and several other mills, with low KER tending to occur each year between May and Aug. This seasonal problem was estimated to cost RM 300 000 annually at Pamol Sabah, from losses in kernels and bunch weight. Pollination studies initiated at Pamol Sabah in December 1993 indicated that there may be a seasonal trend in the population of Elaeidobius kamerunicus, the pollinating weevil, which is closely related to male inflorescence density. High rainfall may also affect pollination by reducing weevil activity and overall viability of available pollen. Assisted pollination gives good fruit set during the months when natural pollination is poor. Severe pruning to induce male inflorescence production is being tested as a less labour intensive alternative to improve fruit set.