<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Soil pH affects the availability of nutrients, which impacts plant growth and development. Similarly, soil pH may also influence microorganisms in the soil, either beneficial or nonbeneficial. One such group of beneficial microorganisms is entomopathogenic nematodes (EPN), parasites of soil-inhabiting insects. Entomopathogenic nematodes have a number of attributes that make them good alternatives to chemical insecticides. The objective of this study was to investigate pH tolerance of 11 steinernematids and six heterorhabditids post exposure to different pH levels. Entomopathogenic nematode populations were exposed to varying pH levels (pH2 to pH11) made up from two different chemical solutions (ammonium-acetate and citrate-phosphate). Entomopathogenic nematode populations are expected to have varying tolerance to different pH levels. The highest infective juvenile survival was obtained from pH3 to pH10 in citrate-phosphate, where all populations displayed >50% survival. <italic>Steinernema carpocapsae</italic> populations had >90% survival at pH3 to pH11 in citrate-phosphate solutions. Overall, the steinernematids had a higher survival range in ammonium-acetate pH solutions compared with the heterorhabditids. Moreover, <italic>Steinernema</italic> spp., <italic>S. carpocapsae</italic> (ScCxrd, ScAll, and ScItalian) and <italic>S. riobrave</italic> showed consistently higher survival in both acidic and alkaline solutions, when compared to the other steinernematids, suggesting that they may be applied in both acidic and alkaline soils. These findings can be of use when selecting EPNs for biological control purposes in the two countries, respectively.</p>
</abstract>

Soil pH affects the availability of nutrients, which impacts plant growth and development. Similarly, soil pH may also influence microorganisms in the soil, either beneficial or nonbeneficial. One such group of beneficial microorganisms is entomopathogenic nematodes (EPN), parasites of soil-inhabiting insects. Entomopathogenic nematodes have a number of attributes that make them good alternatives to chemical insecticides. The objective of this study was to investigate pH tolerance of 11 steinernematids and six heterorhabditids post exposure to different pH levels. Entomopathogenic nematode populations were exposed to varying pH levels (pH2 to pH11) made up from two different chemical solutions (ammonium-acetate and citrate-phosphate). Entomopathogenic nematode populations are expected to have varying tolerance to different pH levels. The highest infective juvenile survival was obtained from pH3 to pH10 in citrate-phosphate, where all populations displayed >50% survival. Steinernema carpocapsae populations had >90% survival at pH3 to pH11 in citrate-phosphate solutions. Overall, the steinernematids had a higher survival range in ammonium-acetate pH solutions compared with the heterorhabditids. Moreover, Steinernema spp., S. carpocapsae (ScCxrd, ScAll, and ScItalian) and S. riobrave showed consistently higher survival in both acidic and alkaline solutions, when compared to the other steinernematids, suggesting that they may be applied in both acidic and alkaline soils. These findings can be of use when selecting EPNs for biological control purposes in the two countries, respectively.

<article-title xml:lang="en">Quantification of pH tolerance levels among entomopathogenic nematodes

Journal of Nematology

This work is licensed under the Creative Commons Attribution 4.0 International License.

Quantification of pH tolerance levels among entomopathogenic nematodes

Soil pH affects the availability of nutrients, which impacts plant growth and development. Similarly, soil pH may also influence microorganisms in the soil,...

Quantification of pH tolerance levels among entomopathogenic nematodes

Publié en ligne: 08 juil. 2021

Pages: 1 - 12

DOI: https://doi.org/10.21307/jofnem-2021-062

Mots clés
Ammonium-acetate, Citrate-phosphate, Entomopathogenic nematodes, pH levels, Survival

© 2021 Zanele Khathwayo et al., published by Sciendo.

This work is licensed under the Creative Commons Attribution 4.0 International License.

Quantification of pH tolerance levels among entomopathogenic nematodes

Publié en ligne: 08 juil. 2021

Pages: 1 - 12

DOI: https://doi.org/10.21307/jofnem-2021-062

Mots clésAmmonium-acetate, Citrate-phosphate, Entomopathogenic nematodes, pH levels, Survival

© 2021 Zanele Khathwayo et al., published by Sciendo.

This work is licensed under the Creative Commons Attribution 4.0 International License.

Mots clés
Ammonium-acetate, Citrate-phosphate, Entomopathogenic nematodes, pH levels, Survival