Lignin content was significantly (P=0.05) different between MR219 and MR253 rice varieties with silicon treatment. Silicon treatment showed significantly higher lignin content of 6.62% in variety MR219, and 5.09% in MR253 compared to the two controls of MR219 (3.60%) and MR253 (3.33%). These were also significantly higher compared to Cu and Zn treatments (Fig 2). The highest lignin content was followed by the rice plant treated with Zn (5.0%) for MR219 and (3.72%) in MR253. The lowest lignin content was recorded in plants treated with Cu (3.37%) for MR219. For MR253, the lignin content of Cu and Zn treatments were not statistically significant and the minimum lignin content was observed in the control.