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POSTERS: Chemical control

Evaluation of a single seedling treatment with nanoscale nutrients to control Fusarium wilt symptoms of chrysanthemum
Lindsay Triplett - Connecticut Agricultural Experiment Station. Wade Elmer- Connecticut Agric Exp Station, Peter Thiel- The Connecticut Agricultural Experiment Station, Elizabeth Roberts- Southern Connecticut State Univ, Rebecca Silady- Southern Connecticut State University

Wilt caused by Fusarium oxysporum f. sp. chrysanthemi is one of the most significant disease problems to affect chrysanthemum (Chrysanthemum morifolium Ramat.). Typical control measures include sanitation and fungicide drenches, but effectiveness of these options are limited by long-term survival of the pathogen in soil. Nanoparticle formulations of copper, manganese, or zinc were recently found to control development of fungal wilt in eggplant and cucurbits. In 2017 and 2018, rooted chrysanthemum transplants were exposed to a single spray treatment of metallic nanoparticles (NP) (500 µg/ml) or water in the greenhouse a week before planting. Seedlings were potted in Fusarium-infested or noninfested potting soil and arranged on landscape fabric in the field. Plant growth and photosynthesis was measured weekly, and disease ratings and dry weights were collected three months after planting. In 2017 and 2018, plants treated with NP Cu were larger than controls, regardless of disease. Estimates of disease in NP Cu-treated plants were less than the inoculated controls in both years and comparable to fungicides. NP Mn and Zn were less effective. The results indicate that nanoparticle treatments may be a useful tool for reducing fungicide use while maximizing production in floriculture. Planting and data collection was performed as a group project by undergraduates participating in a NIFA-funded REEU program, the Summer Undergraduate Fellows in Plant Health and Protection.