The significance of regulating spacing and polybag size in the primary oil palm nursery lies in ensuring an optimal growth environment for uniform and healthy seedlings. However, current recommendations provide limited quantitative evidence on how reduced spacing and smaller polybags influence seedling performance, leaving gap in a practical nursery management guideline. Therefore, an experiment was carried out in the oil palm main nursery to evaluate different spacing design and polybag sizes up to 14 months after planting (MAP). The spacing arrangement of seedlings significantly affected their growth performance compared to polybag sizes. Spacing below 0.75 m produced tall and etiolated seedlings, with height increasingly by 19.60% at 8 MAP and up to 32.00%at 12 to 14 MAP, accompanied by excessively elongated rachis length which made them unsuitable for field planting and problematic for nursery handling. In contrast, using smaller polybag size of 30 cm × 38 cm (12" × 15") resulted in only minor growth differences compared to the standard polybag, with no negative effect on seedling performance or nutrient content up to 12 MAP. There are specific needs for optimum seedling performance unrestricted by growth competition, minimal risk of etiolation, good survival rate, easy nursery maintenance, and reduced maintenance costs for higher profits. Based on current research findings, seedlings considered appropriate for field planting at 10 to 12 MAP must meet some specific criteria; including a bole diameter ranging between 49 to 64 mm, a total frond production between 11 to 15 per seedling, rachis length of frond 3 between 58 to 93 cm, seedling height within the range of 118 to 179 cm, and a petiole cross-section between 1.48 to 2.10 cm2. These findings support the importance of maintaining acceptable spacing while supporting the use of smaller polybags to reduce costs without compromising seedling quality.
Afandi et al. (Thu,) studied this question.