The Effects of a Broad-Spectrum Fungicide on Photosynthetic Yield at Different Developmental Stages of Corn in an Agronomic Setting
Start Date
15-4-2021 2:30 PM
End Date
15-4-2021 2:45 PM
Student's Major
Biological Sciences
Student's College
Science, Engineering and Technology
Mentor's Name
Christopher Ruhland
Mentor's Department
Biological Sciences
Mentor's College
Science, Engineering and Technology
Description
Fungicides are widely used in agronomy to control crop pathogens such as northern corn leaf blight, anthracnose leaf blight, gray leaf spot and southern rust. These diseases can result in a 10-20% reduction in yield in midwestern states. Delaro is a recently introduced broad-spectrum fungicide that contains both strobilurin and triazoles that disrupt mitochondrial respiration and sterol biosynthesis in fungal mycelia. In this study we applied Delaro to different developmental stages of corn to assess any potential impacts on photosynthesis. We applied Delaro on Gold Country (106-96R2P) and Beck’s (5699V2P) varieties at the vegetative 5-leaf (V5) and vegetative tassel (VT) stages using a boom sprayer and an aircraft, respectively, in an agricultural field in Lewisville, MN during the summer of 2020. Leaves were harvested 14-d after application and maximal quantum efficiency of photosystem II (Fv/Fm) was analyzed with a pulse-amplitude modulated chlorophyll fluorometer. There were no significant differences in Fv/Fm between treated and untreated corn leaves or between varieties at the V5 developmental stage. At the tassel stage (VT), leaves that were treated with Delaro had a slight reduction (≈4%) in Fv/Fm in the Gold Country variety. There were no differences in Fv/Fm between varieties that had been treated at both developmental stages. Previous studies have found that other types of fungicides can greatly reduce Fv/Fm, however our results generally agree with current studies that show both strobilurin and triazoles do not interfere with or can have slight positive effects on photosynthesis in healthy plants. These findings must be interpreted with caution, visual inspection of the crop did not reveal the presence of any disease pressures in our experimental plots and the presence of a fungal pathogen might alter results.
The Effects of a Broad-Spectrum Fungicide on Photosynthetic Yield at Different Developmental Stages of Corn in an Agronomic Setting
Fungicides are widely used in agronomy to control crop pathogens such as northern corn leaf blight, anthracnose leaf blight, gray leaf spot and southern rust. These diseases can result in a 10-20% reduction in yield in midwestern states. Delaro is a recently introduced broad-spectrum fungicide that contains both strobilurin and triazoles that disrupt mitochondrial respiration and sterol biosynthesis in fungal mycelia. In this study we applied Delaro to different developmental stages of corn to assess any potential impacts on photosynthesis. We applied Delaro on Gold Country (106-96R2P) and Beck’s (5699V2P) varieties at the vegetative 5-leaf (V5) and vegetative tassel (VT) stages using a boom sprayer and an aircraft, respectively, in an agricultural field in Lewisville, MN during the summer of 2020. Leaves were harvested 14-d after application and maximal quantum efficiency of photosystem II (Fv/Fm) was analyzed with a pulse-amplitude modulated chlorophyll fluorometer. There were no significant differences in Fv/Fm between treated and untreated corn leaves or between varieties at the V5 developmental stage. At the tassel stage (VT), leaves that were treated with Delaro had a slight reduction (≈4%) in Fv/Fm in the Gold Country variety. There were no differences in Fv/Fm between varieties that had been treated at both developmental stages. Previous studies have found that other types of fungicides can greatly reduce Fv/Fm, however our results generally agree with current studies that show both strobilurin and triazoles do not interfere with or can have slight positive effects on photosynthesis in healthy plants. These findings must be interpreted with caution, visual inspection of the crop did not reveal the presence of any disease pressures in our experimental plots and the presence of a fungal pathogen might alter results.
