Photoperiodic and Gibberellin-induced Growth and Flowering Responses of Gaillardia × grandiflora

Abstract

Gaillardia × grandiflora Van Houtte ‘Dazzler’ and ‘Goblin’ were induced to flower under long days. Applications of GA4+7 (GA) substituted for long days and promoted flowering under short days in the same amount of time required by untreated, photoperiodically induced plants. Although cultivar and photoperiod dependent, GA also increased scape length and reduced scape caliper, flower head diameter and ray floret number. Leaf production was accelerated by several weekly applications of GA.