Effects of silicon amendment to rice plants on leaf-folding behaviors of Cnaphalocrocis medinalis

A number of studies have shown that silicon amendment can enhance rice resistance to pests and diseases including the rice leaf folder (RLF), Cnaphalocrocis medinalis (Guenée). However, the impact of silicon (Si) amendment on the leaf-folding behavior of RLF larvae remains unclear. Therefore, a study with factorial design combining rice cultivars (susceptible Taichung Native 1 and moderately resistant Zhongzheyou 8) and Si treatments (2.0 and 0.0 mm) was conducted to measure their effects on the leaf-folding behaviors of RLF larvae and the physicochemical traits of rice leaves.

Si amendment significantly prolonged the leaf-folding initiation time and primary leaf-fold formation time, shortened the length of primary leaf-fold, and reduced the leaf-folding speed and preference for Si-amended plants. Correlation and principal component (PC) analyses revealed that, among the leaf physicochemical traits that showed significant correlation with leaf-folding speed, the area of bulliform cell, length of macrohair on the adaxial surface, and lignin content exhibited loading rates of 0.275, 0.280, and 0.282, respectively, on PC1; and the number of macrohairs on the abaxial surface, moisture content, and Si content showed loadings of 0.373, 0.398 and 0.410, respectively, on PC2. Among these traits, only the number of macrohairs on the abaxial surface was not under significant influence of Si treatment.

Si application enhances silicification in rice leaves and modifies physicochemical traits, thereby reinforcing physical resistance against larval leaf-folding behaviors of RLF. © 2026 Society of Chemical Industry.