Silicon builds resilience in strawberry plants against both strawberry powdery mildew Podosphaera aphanis and two-spotted spider mites Tetranychus urticae.

Bo Liu,Avice Hall,Keith Davies,Birinchi Sarma

doi:10.1371/journal.pone.0241151

Bo Liu, Avice Hall + Show 2 more

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https://doi.org/10.1371/journal.pone.0241151

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Abstract

Silicon is found in all plants and the accumulation of silicon can improve plant tolerance to biotic stress. Strawberry powdery mildew (Podosphaera aphanis) and two-spotted spider mite (Tetranychus urticae) are both detrimental to strawberry production worldwide. Two field trials were done on a UK commercial strawberry farm in 2014 and 2015, to assess the effects of silicon nutrient applied via the fertigation system on P. aphanis and T. urticae. The silicon treatments decreased the severity of both P. aphanis and T. urticae in two consecutive years on different cultivars. The percentage leaf area infected with P. aphanis mycelium from silicon treated plants were 2.19 (in 2014) and 0.41 (in 2015) compared with 3.08 (in 2014) and 0.57 (in 2015) from the untreated plants. The etiology of the pathogen as measured by the Area Under the Disease Progress Curve from silicon (with and without fungicides) treatments was 152.7 compared with 217.5 from non-silicon (with and without fungicides) treatments for the overall period of 2014–2015. The average numbers of T. urticae recorded on strawberry leaves were 1.43 (in 2014) and 1.83 (in 2015) in plants treated with silicon compared with 8.82 (in 2014) and 6.69 (in 2015) in untreated plants. The silicon contents of the leaves from the silicon alone treatment were 26.8 μg mg-1 (in 2014) and 22.2 μg mg-1 (in 2015) compared with 19.7 μg mg-1 (in 2014) and 21.4 μg mg-1 (in 2015) from the untreated. The silicon nutrient root application contributed to improved plant resilience against P. aphanis and T. urticae. Silicon could play an important role in broad spectrum control of pests and diseases in commercial strawberry production.

Highlights

Silicon (Si) is the second most abundant mineral element in the soil and constitutes ca. 28% of the earth’s crust [1, 2]
The silicon concentration of the sample material was calculated by using the equation y = 1.0957x, where y is the absorbance of silicon at 650nm (CECIL 1021 Spectrophotometer, 1000 series, Cambridge, UK) and x is the concentration of silicon. Results from both 2014 and 2015 experiments were consistent; strawberry plants that received weekly silicon application had reduced severities of both P. aphanis and T. urticae compared with the untreated control plants
In the 2014 experiment, strawberry plants from the 0.017% Si plus commercial fungicide treatment had the smallest disease scores (AUDPC = 63) (P < 0.001) and infection rate (r = 0.0012) among all treatments (Table 2; Fig 1A)

Summary

Introduction

Silicon (Si) is the second most abundant mineral element in the soil and constitutes ca. 28% of the earth’s crust [1, 2]. Silicon (Si) is the second most abundant mineral element in the soil and constitutes ca. 28% of the earth’s crust [1, 2]. Silicon is found in all plants but not considered an essential element for plant growth (International Plant Nutrition Institute, http://www.ipni.net/nutrifactsnorthamerican), as it is not directly involved in the plant metabolic process [2]. Silicon builds resilience in strawberries against P. aphanis and T. urticae

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