Abstract:
Optimum plant spacing is among key agronomic parameters that influence on growth and yield in rice (Oryza sativa L.). A field experiment was conducted to evaluate the growth and yield response of mechanical transplanted rice at the Rice Research Station, Paranthan during Maha season, 2016/17. The machine transplanting method considered as practical option to minimize the labor usage with the timeliness cultivation of rice. Recent past, rice transplanter was introduced to paddy farmers of Kilinochchi district by the governmentof Sri Lanka. However, adaptation of this method is still low due to socio-economic background and lack of technical information. Four rows of man-propelled paddy KUBOTA (SPW 48c) transplanter was used in this study with 30cm row spacing (non-adjustable) and 5 within row spacing levels (12, 14, 16, 18 and 21 cm), replicated four times in each. The rice variety Co-10 was used with the plot size of 4m×6m. The plant height, number of tillers at different stages, percentage of canopy coverage and yield components such as panicle per hill, panicle length, grain yield and 1000 grains weight were recorded. Results revealed that the spacing of 30cm×16 cm produced significantly higher number of tillers and panicles than others. The spacing of 30cm×16 cm recorded the highest (p<0.05) percentage of canopy coverage (75 %), 1000 grain weight (24.9 g) and grain yield (7921.9 kg/ha). This study concluded that spacing of 30cm×16cm can be considered as optimum plant density for machine transplanted rice for the variety Co-10 compared to other tested spacing in this region.
