The Establishment of Direct-Seeded Rice Cultivation in the Muda Irrigation Scheme, Malaysia

1. Yield and yield components of direct seeded rice plant in Muda area

Abstract

The grain yield and yield components of direct-seeded rice plant were studied for two seasons, 2nd season in 1988 and 1st season in 1989, in the Muda Irrigation Scheme, Malaysia. The coefficient of variation based on the sampling unit of each yield component (including seedling number) under identical field conditions was much higher in direct-seeded plants than in transplanted ones, especially in number of plants per unit area.
A high correlation was found between the yield and the spikelet number per m² as seen in transplanted plant in the tropics, while there existed no correlation between the yield and the ripening percentage. The spikelet number per m² was strongly affected by the panicle number per m², but not by the spikelet number per panicle. The panicle number per m² was governed by the established seedling number per m². Therefore, the yield and the spikelet number per m² were related to the established seedling number. It is noteworthy that when the established seedling number per m² exceeded 180, its contribution toward further yield increase was not distinct. When the established seedling number per m² was less than 150, the yield declined sharply in proportion to the decrease in the established seedling number. Seedling establishment of 150-200 plants per m² is considered to be optimal for obtaining stable rice yield in the Muda area, and, for achieving higher yields, it is important to reduce the spotty areas where the seedling establishment is less than 150 plant/m².