Effects of silicon amendment on the occurrence of rice insect pests and diseases in a field test

Abstract

Rice is one of the most important staple foods for the world population, but it is attacked by a number of destructive pests. While evidence from greenhouse and laboratory tests has shown that silicon (Si) amendment can confer enhanced resistance to pests in rice, few studies have directly demonstrated the Si-mediated protection from pests in a field situation. In this study, field plots with silicon amendments at 0, 75, 150 and 300 kg SiO2 ha−1 in early- and late-season rice were employed to evaluate the effects of silicon amendment on the occurrence of major insect pests and diseases and rice yield. Compared with the control plots without silicon amendment, plant damage by stem borer and leaf folder and population size of planthopper were significantly lower in three to five of the seven monitoring observations in each season in the plots amended with 300 kg SiO2 ha−1. The disease index of rice blast in the early-season rice was lower in the plots amended with Si at 300 kg SiO2 ha−1 than in the control plots, while Si protection from rice blast in the late-season rice and from rice sheath blight in the early-season rice were not apparent. An insignificant increase of rice yield by 16.4% (604 kg ha−1) was observed in the plots amended with 300 kg SiO2 ha−1 over the control plots. Our results indicate that Si amendment at 300 kg SiO2 ha−1 can provide substantial protection from some of the rice pests under field conditions. These findings support the recommendation of silicon amendment as a key component of integrated management of rice pests.

Keywords

• silicon
• rice
• insect pest
• disease
• yield
• plant resistance