A comparison of a tannic acid biopesticide and a commercial fungicide used for crop protection against Fusarium head blight

WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
Brooke Bien (Creator)
Institution
Western Carolina University (WCU )
Web Site: http://library.wcu.edu/
Advisor
Scott Huffman

Abstract: Fungicides are typically used on crops to prevent pathogenic diseases. However, there are biopesticides that can inhibit the same pathogens as several fungicides. In particular, tannic acid can inhibit the growth of Fusarium graminearum, a fungus that causes Fusarium head blight. Fusarium head blight is a disease that a ffects gramineous hosts. Fungicides containing tebuconazole and prothioconazole, such as ProsaroTM, are commonly used to prevent the disease. As a safer alternative, tannic acid wax emulsions have been formulated as a treatment method. Analytical techniques consisting of QuEChERS extractions and HPLC have been developed to measure the residual amounts of each treatment. Determining the residual amounts will indicate whether the tannic acid formulation is adhering to the sample long enough to prevent the crop disease, as well as if it is rainfast. After developing methods to extract and analyze tannic acid, prothioconazole, and tebu-conazole residues, samples of barley grain were analyzed. Field trials of barley plots were used to examine the eff ectiveness of the tannic acid biopesticide. The e ffectiveness of the tannic acid biopesticide was determined by analysis of DON, deoxynivalenol, on the grain samples. DON is produced from the Fusarium fungus. Therefore, a low DON concentration means the sample was slightly infected, whereas a high DON concentration means the sample was more infected. An outside party performed these analyses. The average DON concentrations of the treatments seem to con rm that tannic acid treated barley is less infected than untreated barley. However, SAS analysis confi rms that there is no signifi cant di fference in DON concentration of tannic acid treated barley and untreated barley. Grain samples from these plots were also analyzed for tannic acid or prothioconazole and tebuconazole residue.It was hypothesized that since treatment occurred prior to grain formation, that little to no residue would be present on the grain at harvest. After analysis, it was determined that this hypothesis was correct.How long the biopesticide would remain on the plant was also examined. Tannic acid was present on Euonymus alata up to three weeks and on Liriope muscari for up to four weeks. This time period is ideal considering the plant only needs to be protected during a specifi c growth stage lasting approximately 10 days. Additionally, there would be little to no residue present on the grain at harvest. Overall, this research found that tannic acid could be eff ectively used to protect crops from FHB.

Additional Information

Publication
Thesis
Language: English
Date: 2016
Keywords
Biopesticide, Fusarium head blight, HPLC, Prosaro, QuEChERS, Tannic acid
Subjects
Plants, Protection of
Agricultural pests -- Control
Natural pesticides
Tannins
Agricultural chemicals
Fusarium diseases of plants
Barley -- Diseases and pests

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