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Abstract
Peanut (Arachis hypogaea) was planted on four dates from late April through early June. Earlier plantings had more stem rot (Sclerotium rolfsii), and yield was consistently lowest for the June planting date. Studies on a thermogradient table showed the optimal temperatures for sclerotial germination, mycelial growth and leaflet colonization with S. rolfsii were > 24, 32 and 33oC, respectively. Management with early-season applications of prothioconazole was also investigated. In-furrow sprays were not as effective as banded sprays, but early-season banded applications reduced both stem rot and leaf spot, and increased yield in some trials. Results were similar for sprays made at 21 versus 35 days after planting. Banded applications were more effective than broadcast sprays, and results were similar from spray volumes of 94-374 L/ha. Overall, early-season, banded applications of prothioconazole were shown to offer more consistent disease control and pod yield, especially in years with early stem rot epidemics.