Efecto del Etefón (ETILENO) sobre la promoción floral de Billbergia pyramidalis (Sims) Lindley

billbergia pyramidalis is an important ornamental bromeliad for landscape and potting. the capacity of ethylene to promote its flowering was investigated by spraying potted plants with ethephon (ethylene releaser) in three experiments conducted in greenhouse at 25,4 oc and 74 % rh. in the first experiment, 6-month old plants having from 12 to 18 leaves were sprayed with 0, 3, 6 y 9 mg·l-1 of ethephon in two applications at weekly interval. all treated plants flowered, except the control; however, ethephon concentrations above 3 mg·l-1 resulted in incomplete and deformed inflorescences, and early senescence. in a second trial, 3-month old plants ranging from 10 to 13 leaves were sprayed with 0, 1, 2 y 3 mg·l-1 of ethephon in one or two applications at weekly interval. flowering occurred 9 days after treatments, except the control. the greatest flowering (55 %) was obtained at 1 and 2 mg·l-1 of ethephon in one application. the highest peduncle growth rate occurred after 16-24 days, and the largest inflorescence diameter after 30 days being highest at 1 mg·l-1 (one or two applications), and 2 mg·l-1 (one application). the inflorescence longevity was 7-10 days, and the senescence was faster in the highest concentration treatment. in the third experiment, similar flowering (75 %) was found for both young and adult plants, which received one application of ethephon 1 mg·l-1, although the inflorescences coming from adult plants exhibited longer peduncle and higher diameter than those from young plants. flowering of this species is promoted by ethylene being the best option one application of ethephon 1 mg·l-1.