Metal Micronutrient and Silicon Concentration Effects on Growth and Susceptibility to Pythium Root Rot for Hydroponic Lettuce (<i>Lactuca sativa</i>)
The objectives were to evaluate the effects of increasing metal micronutrient concentrations and silicon (Si) concentrations on plant growth and susceptibility to Pythium root rot with hydroponically grown lettuce (<i>Lactuca sativa</i>). In the first experiment, lettuce was grown in hyd...
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MDPI AG
2023-06-01
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| Series: | Horticulturae |
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| Online Access: | https://www.mdpi.com/2311-7524/9/6/670 |
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| author | Kalyn M. Helms Ryan W. Dickson Matthew B. Bertucci Alejandro A. Rojas Kristen E. Gibson |
| author_facet | Kalyn M. Helms Ryan W. Dickson Matthew B. Bertucci Alejandro A. Rojas Kristen E. Gibson |
| author_sort | Kalyn M. Helms |
| collection | DOAJ |
| description | The objectives were to evaluate the effects of increasing metal micronutrient concentrations and silicon (Si) concentrations on plant growth and susceptibility to Pythium root rot with hydroponically grown lettuce (<i>Lactuca sativa</i>). In the first experiment, lettuce was grown in hydroponic solutions with metal micronutrients iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) supplied at either 0, 2.5, 5, or 10 mg∙L<sup>−1</sup>. A standard commercial hydroponic solution was also included as a control, with metal micronutrients supplied at 2 Fe, 1 Mn, 0.5 Cu, and 0.5 Zn mg∙L<sup>−1</sup>. In the second experiment, hydroponic lettuce was grown with Si at 0, 7, 14, 28, and 56 mg∙L<sup>−1</sup>. Hydroponic treatment solutions for both experiments were either dosed with <i>Pythium myriotylum</i> (<i>Pythium</i> treatment) at 1.80 × 10<sup>4</sup> oospores per L or deionized water as a non-<i>Pythium</i> control. Data were collected on leaf SPAD chlorophyll content, shoot height and width, total plant fresh mass, and root disease severity. Increasing the Cu concentration in solution decreased <i>Pythium</i> disease severity but reduced lettuce growth and yield. Increasing the concentration of the other metal micronutrients also tended to reduce lettuce growth but had no significant influence on root disease. Supplementing the hydroponic solution with Si had no effect on Pythium root disease severity and slightly decreased lettuce growth at 56 mg∙L<sup>−1</sup> Si. Results of this study suggest that the management of micronutrients and Si nutrition is not an effective strategy and, at best, a risky strategy for controlling <i>Pythium</i> in hydroponic lettuce. Growers would likely benefit from maintaining metal micronutrient and Si concentrations within the ranges of (in mg∙L<sup>−1</sup>) 0.5 to 5.5 for Fe, 0.1 to 2.0 for Mn, 0.1 to 0.6 for Cu, 0.1 to 0.6 for Zn, and 0 to 28 for Si for many hydroponic crops. Supplementing Si has the potential to negatively influence plant growth and quality for certain plant species, and testing is necessary to evaluate phytotoxicity risks prior to implementing in commercial practice. Overall, successful mitigation of root rot pathogens in commercial hydroponic production requires the combination of proper sanitation, best management and cultural practices, appropriate hydroponic system design, and the implementation of a water treatment system with proper design and a multi-barrier approach. |
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| last_indexed | 2024-03-11T02:23:54Z |
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| spelling | doaj.art-dd5494f7bc264e37b31944435e0bceee2023-11-18T10:40:59ZengMDPI AGHorticulturae2311-75242023-06-019667010.3390/horticulturae9060670Metal Micronutrient and Silicon Concentration Effects on Growth and Susceptibility to Pythium Root Rot for Hydroponic Lettuce (<i>Lactuca sativa</i>)Kalyn M. Helms0Ryan W. Dickson1Matthew B. Bertucci2Alejandro A. Rojas3Kristen E. Gibson4Department of Horticulture, University of Arkansas System Division of Agriculture, Fayetteville, AR 72701, USADepartment of Horticulture, University of Arkansas System Division of Agriculture, Fayetteville, AR 72701, USADepartment of Horticulture, University of Arkansas System Division of Agriculture, Fayetteville, AR 72701, USADepartment of Entomology and Pathology, University of Arkansas System Division of Agriculture, Fayetteville, AR 72701, USADepartment of Food Science, Center for Food Safety, University of Arkansas System Division of Agriculture, Fayetteville, AR 72701, USAThe objectives were to evaluate the effects of increasing metal micronutrient concentrations and silicon (Si) concentrations on plant growth and susceptibility to Pythium root rot with hydroponically grown lettuce (<i>Lactuca sativa</i>). In the first experiment, lettuce was grown in hydroponic solutions with metal micronutrients iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) supplied at either 0, 2.5, 5, or 10 mg∙L<sup>−1</sup>. A standard commercial hydroponic solution was also included as a control, with metal micronutrients supplied at 2 Fe, 1 Mn, 0.5 Cu, and 0.5 Zn mg∙L<sup>−1</sup>. In the second experiment, hydroponic lettuce was grown with Si at 0, 7, 14, 28, and 56 mg∙L<sup>−1</sup>. Hydroponic treatment solutions for both experiments were either dosed with <i>Pythium myriotylum</i> (<i>Pythium</i> treatment) at 1.80 × 10<sup>4</sup> oospores per L or deionized water as a non-<i>Pythium</i> control. Data were collected on leaf SPAD chlorophyll content, shoot height and width, total plant fresh mass, and root disease severity. Increasing the Cu concentration in solution decreased <i>Pythium</i> disease severity but reduced lettuce growth and yield. Increasing the concentration of the other metal micronutrients also tended to reduce lettuce growth but had no significant influence on root disease. Supplementing the hydroponic solution with Si had no effect on Pythium root disease severity and slightly decreased lettuce growth at 56 mg∙L<sup>−1</sup> Si. Results of this study suggest that the management of micronutrients and Si nutrition is not an effective strategy and, at best, a risky strategy for controlling <i>Pythium</i> in hydroponic lettuce. Growers would likely benefit from maintaining metal micronutrient and Si concentrations within the ranges of (in mg∙L<sup>−1</sup>) 0.5 to 5.5 for Fe, 0.1 to 2.0 for Mn, 0.1 to 0.6 for Cu, 0.1 to 0.6 for Zn, and 0 to 28 for Si for many hydroponic crops. Supplementing Si has the potential to negatively influence plant growth and quality for certain plant species, and testing is necessary to evaluate phytotoxicity risks prior to implementing in commercial practice. Overall, successful mitigation of root rot pathogens in commercial hydroponic production requires the combination of proper sanitation, best management and cultural practices, appropriate hydroponic system design, and the implementation of a water treatment system with proper design and a multi-barrier approach.https://www.mdpi.com/2311-7524/9/6/670<i>Pythium myriotylum</i>hydroponicsoilless culturemicronutrientssiliconlettuce |
| spellingShingle | Kalyn M. Helms Ryan W. Dickson Matthew B. Bertucci Alejandro A. Rojas Kristen E. Gibson Metal Micronutrient and Silicon Concentration Effects on Growth and Susceptibility to Pythium Root Rot for Hydroponic Lettuce (<i>Lactuca sativa</i>) Horticulturae <i>Pythium myriotylum</i> hydroponic soilless culture micronutrients silicon lettuce |
| title | Metal Micronutrient and Silicon Concentration Effects on Growth and Susceptibility to Pythium Root Rot for Hydroponic Lettuce (<i>Lactuca sativa</i>) |
| title_full | Metal Micronutrient and Silicon Concentration Effects on Growth and Susceptibility to Pythium Root Rot for Hydroponic Lettuce (<i>Lactuca sativa</i>) |
| title_fullStr | Metal Micronutrient and Silicon Concentration Effects on Growth and Susceptibility to Pythium Root Rot for Hydroponic Lettuce (<i>Lactuca sativa</i>) |
| title_full_unstemmed | Metal Micronutrient and Silicon Concentration Effects on Growth and Susceptibility to Pythium Root Rot for Hydroponic Lettuce (<i>Lactuca sativa</i>) |
| title_short | Metal Micronutrient and Silicon Concentration Effects on Growth and Susceptibility to Pythium Root Rot for Hydroponic Lettuce (<i>Lactuca sativa</i>) |
| title_sort | metal micronutrient and silicon concentration effects on growth and susceptibility to pythium root rot for hydroponic lettuce i lactuca sativa i |
| topic | <i>Pythium myriotylum</i> hydroponic soilless culture micronutrients silicon lettuce |
| url | https://www.mdpi.com/2311-7524/9/6/670 |
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