The Effects of Planting Range and Weed Management on Growth and Yield of Rice (Oryza sativa L.) Using Modified SRI (The System of Rice Intensification)

Using modified SRI (The System Rice of Intensification) was aimed at determining the optimum planting range and frequency of weeds management that could increase rice productivity. The research was consisted of two factors, planting range and frequency of weeds management. The trials were arranged in factorial using Randomized Block Design (5x4) and three replications. The first factor  was five levels of planting range, 20 x 20 cm; 20 x 25 cm; 25 x 25 cm; 25 x 30 cm; and 30 x 30 cm.  While the second factor was four levels of weeds management (manually) frequency, once (30 days after planting (DAP); twice (20; 40 DAP); 3 times (20; 30; 40 DAP); and 4 times (10; 20; 30; 40 DAP). Parameters measured were the maximum number of tillers, crops growth rate, net assimilation rate, number of productive tillers, the weight of 1000 seeds, seeds weight per clump, and seeds weight per hectare. The result showed that planting range 20 cm x 25 cm and three times frequency of weeding per planting season was the best interaction with the productivity 9.005 t ha-1.  Rice cultivation technique by giving the height of water surface 10 cm under the soil surface, a distance of furrows 2 m, the dosage of compost 10 ton/ha,  planting range  20 x 25 cm , and frequency of weeding three times per planting season could increase rice yield as much as 50.08 %.