Integrating Soil Silicon Amendment into Management Programs for Insect Pests of Drill-Seeded Rice.

James Villegas,Rebecca Pearson,Michael Way,Michael Stout

doi:10.3390/plants6030033

James Villegas, Rebecca Pearson + Show 2 more

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https://doi.org/10.3390/plants6030033

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Abstract

Silicon soil amendment has been shown to enhance plant defenses against insect pests. Rice is a silicon-accumulating graminaceous plant. In the southern United States, the rice water weevil and stem borers are important pests of rice. Current management tactics for these pests rely heavily on the use of insecticides. This study evaluated the effects of silicon amendment when combined with current management tactics for these rice insect pests in the field. Field experiments were conducted from 2013 to 2015. Rice was drill-planted in plots subjected to factorial combinations of variety (conventional and hybrid), chlorantraniliprole seed treatment (treated and untreated), and silicon amendment (treated and untreated). Silicon amendment reduced densities of weevil larvae on a single sampling date in 2014, but did not affect densities of whiteheads caused by stem borers. In contrast, insecticidal seed treatment strongly reduced densities of both weevil larvae and whiteheads. Higher densities of weevil larvae were also observed in the hybrid variety in 2014, while higher incidences of whiteheads were observed in the conventional variety in 2014 and 2015. Silicon amendment improved rice yields, as did chlorantraniliprole seed treatment and use of the hybrid variety.

Highlights

Silicon (Si) is the second most abundant element, after oxygen, in the earth’s crust, and is almost exclusively found in the form of silicon dioxide (SiO2 ), in association with a wide array ofSi-bearing minerals in crystalline, poorly crystalline, and amorphous phases [1,2]
We evaluated the control effects of soil silicon amendment with insecticide stem borer treatment and management rice varieties for the management of rice insect pests
In rice and other cereals, there is a lack of field studies showing the effect of silicon on insect pests, a number of studies have shown the adverse effects of silicon soil amendment on insect and a lack of studies investigating the effects of silicon on root feeders

Summary

Introduction

Silicon (Si) is the second most abundant element, after oxygen, in the earth’s crust, and is almost exclusively found in the form of silicon dioxide (SiO2 ), in association with a wide array ofSi-bearing minerals in crystalline, poorly crystalline, and amorphous phases [1,2]. Silicon is taken up by plants by the lateral roots via active, passive, and rejective mechanisms [3], and is transported to the shoot as monosilicic acid, where it is deposited as solid, amorphous, hydrated silica (SiO2 .nH2 O) known as pytoliths [4,5]. Monocotyledons such as wheat, sugarcane, rice, and barley are classified as high accumulators of silicon containing 10–100 g kg−.

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