DEWINGING DIPTEROCARP SEEDS

Abstract

When mass flowering season occurs every three to eight years in the tropics, seeds of many forest species tend to mature at about the same time. They include the majority of dipterocarp seeds that are 'winged' and classified as recalcitrant. In order to secure as many planting materials as possible, harvested seeds must be planted immediately. Previous studies indicated that dewinging facilitates seed germination and is advantageous when sowing space is limited. Usually seed dewinging is processed manually, which is labour intensive, time consuming but critical in retaining the quality of recalcitrant seeds. An experiment was carried out to reduce processing time using a prototype machine, namely seed dewinger machine, produced by the Forest Research Institute Malaysia. Mechanical dewinging of four dipterocarp species significantly reduced the processing time without affecting seed viability. The process of dewinging was longer for seeds with greater wing length, smaller wing waist and which were heavier. The best-fit model for the duration of processing was determined as time = 0.65548 + 0.0297 (length) - 0.379 (waist) + 0.134 (weight).