Experiments conducted from 2007 to 2009 evaluated germination of 11 peanut runner-type cultivars. Germination was evaluated in Petridishes incubated over a thermal gradient ranging from 14 to 30°C at 1.0？C increments. Beginning 24？hr after seeding, peanut was counted as germinated when radicles were greater than 5？mm long, with removal each day. Germination was counted daily for seven days after seeding. Growing-degree day (GDD) accumulation for each temperature increment was calculated based on daily mean temperature for that Petri dish. Two indices were obtained from a logistic growth curve used to elucidate seed germination by cultivar: (1) maximum indices of germination and (2) GDD value at 80% germination (Germ80), an indication of seed vigor the lower the Germ80 value, the greater the seed lot vigor. Based on the two indices, seed lots “AT 3081R”, “AP-3”, “GA-06G”, and “Carver” had the strongest seed vigor (Germ80 26 to 47 GDD) and a high maximum incidence of germination rate (80 to 94%). Seed lots of “C99-R”, “Georgia-01R”, “Georgia-02C”, and “Georgia-03L” had inconsistent seed performance, failing to achieve 80% germination in at least two of three years. 1. Introduction United States peanut production in 2010 (510,308？ha) centered mainly in the southern states of Georgia (226,623？ha, 44%), Alabama (75,676？ha, 15%), Florida (54,632？ha, 11%), North Carolina (35,612？ha, 7%), South Carolina (26,605？ha, 5%), and Mississippi (7,284？ha, 1%), with another concentration in the south central states of Texas (64,749？ha, 13%) and Oklahoma (8,094？ha, 2%) [1]. The value of peanut to these regions exceeded one billion US dollars in crop sales each year [1]. Producers plant many different cultivars across this region including runner and Virginia market types. Regardless of where peanuts are grown, poor seedling emergence can be an issue [2]. Prior to the 1990s, producers in the southeast planted peanut beginning in early April [3]. However, the incidence of tomato spotted wilt Tospovirus (TSWV) increased rapidly across the peanut belt in the 1990s, especially on susceptible cultivars [4]. Research indicated that later planting date could decrease TSWV incidence, and therefore a shift toward mid- to late-May planting of peanut occurred [5]. Peanut breeding efforts were focused on developing TSWV-resistant cultivars [4]. Initial studies from 1998 to 2000 indicated that cultivars tolerant or resistant to TSWV could be successfully grown with minimal yield losses if growers planted in May [5, 6]. “Georgia Green” [7] became the standard for peanut production in
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