Effect of Fungicide Programs on Plant Health, Maturity, Yield, and Quality of Two Peanut Cultivars.

Peanut (Arachis hypogaea L.) plants are susceptible to several diseases during the growing season. Different fungicides have been used to provide control to these diseases. It is important to implement sound fungicide programs to keep peanut plants healthy and protect yield; however, information on the effects that commercially-available fungicides have on pod maturity and quality of peanuts is scant. A field experiment was conducted on the University of Georgia Ponder Farm in Tifton, GA in 2018 to determine the effects of different fungicide programs on peg strength, pod maturity, yield, and quality of two peanut cultivars across four harvest dates. Fungicide programs consisted of a low-input control with Bravo Weather Stik (chlorothalonil), Bravo Weather Stik plus Tebuconazole, and Elatus (azoxystrobin, Solatenol). The two cultivars evaluated were Georgia-06G and Georgia-09B. The four harvest dates were determined by adjusted growing degree day units of 2400, 2500, 2600, and 2700 GDD’s. All treatments were replicated four times and arranged in a randomized complete block design. Height and width were measured 24 days after planting (DAP) and 50 DAP. Leaf spot occurrence was recorded 113 DAP and at the digging of each harvest date. Tomato spotted wilt virus and southern stem blight were also assessed prior to harvest. Pods samples were collected and assessed for peg strength, maturity, yield, and grade at each of the four harvest dates. Preliminary analysis of the results suggested that fungicide programs influenced yield and the overall health of the crop throughout the growing season. The Elatus program seemed to provide higher disease control than the two other fungicide programs, resulting in higher yield and lower disease incidence. Harvest date resulted in variations among grade, maturity, peg strength, and disease severity, and 2500 aGDD indicated to be the most suitable for a high yield and low disease incidence.