Growth, Flowering, and Survival of Gaillardia pulchella Foug. Based on Seed Source and Growing Location

Abstract

Containerized Gaillardia pulchella Foug. derived from seed of natural populations in east Texas (ET), northeast Florida (NEF), central west Florida (CWF), central east Florida (CEF), and southeast Florida (SEF) were transplanted in early April to field sites located in northwestern, northern central, and southeastern Florida. During the 22-week study, plants were irrigated only during the first 2 weeks after transplanting to aid establishment. Plant growth was assessed by calculating growth indices (GI, a gauge of plant size based on height and width) at first and second flowering peaks, and by recording shoot dry weight at first flowering peak. Growth index varied among ecotypes and sites but ecotype × site was nonsignificant. At 22 weeks, NEF and ET had GIs about 18% larger than CEF or SEF. Plants grew more at the two northern sites than in southeastern Florida, which was probably due to the loamy soils at the northern sites. Averaged over the entire study, visual ratings of vigor, flowering, and quality varied by ecotype; ecotype × site interactions were nonsignificant. All ecotypes except CEF exhibited equally high vigor, flowering, and quality. Plants in southeastern Florida had lower vigor and flowering ratings than those at the two northern sites. Survival varied by ecotype and site, and ecotype × site was significant. Within a site, survival of NEF, SEF, and ET was equally high (83% to 100%). Also, CWF had 100% survival at the two northern sites, yet no CWF plants survived past week 16 in southeastern Florida. There was no short-term home region advantage to necessitate using local G. pulchella ecotypes in residential or commercial landscapes. CEF and CWF performed poorly in southeastern Florida, which was probably related to excessive June rain.