Peanut (Arachis hypogaea L.) is a leguminous plant in the Fabaceae family and an important oil and cash crop worldwide (Sanders, 2003). Peanut plants require a long and hot growing season with a water requirement of approximately 48 cm well distributed over the season, reaching over 3.8 cm per week during peak flowering (Porter, 2021). The United States is one of the major worldwide peanut-producing countries, after China, India, Nigeria, and Sudan (USDA/NASS, 2019a). In the United States, peanuts are most grown in the Southeast region due to optimal weather conditions, with a particular focus in Georgia, where the production is greater compared to other producing states. Peanut is generally susceptible to several diseases that can affect growth and yield. Tomato spotted wilt (TSW) caused by Tomato spotted wilt virus (TSWV), early leaf spot (Passalora arachidicola) and late leaf spot (Nothopassalora personata) are the most spread diseases in Georgia peanut fields (Shokes and Culbreath, 1997). The latter two are responsible for losses of tens of millions of dollars annually in Georgia alone ($12.5 million in 2018) if not controlled (Kemerait, 2018). In order to control the dispersion of different peanut diseases, many fungicide programs have been developed and tested in the past. Information on the effect of commercially-available fungicide programs on the photosynthetic efficiency of leaves as well as maturity and physiological quality of seeds are still needed for the peanut crop. Thus, the overall goals of this study are to identify the most cost-effective fungicide program that maintains great photosynthetic activity of leaves, contributing to increased productivity and seed maturity as well as to address the effectiveness of dodine-based fungicide programs as a replacement of chlorothalonil for leaf spot control.
