Growth and canopy structure of rice plants grown under field conditions as affected by Si application

In many studies using solution culture or pot culture it was reported that dry matter and yield production of rice plants can be improved by silicon application. There is limited information, however, on field-grown rice. The purpose of this study was to evaluate the effect of the application of Si (in the form of silica gel) on the growth, yield, and canopy structure of rice plants grown under field conditions. The results obtained were as follows: 1) No significant differences in the growth and yield of rice plants with and without Si application were observed under high availability of SiO2. However, the canopy structure of the rice plants was improved by Si application. The distance between the desirable position and the actual position of the top leaf was shorter in the + Si treatment than in the - Si treatment at the maximum tiller number stage. 2) The relative light intensity was higher in the + Si treatment than in the - Si treatment at the maximum tiller number stage, irrespective of the plant height. At the booting stage, the relative light intensity in the upper canopy was lower in the + Si treatment than in the - Si treatment. A higher rate of Si gave a lower light extinction coefficient at the maximum tiller number stage.