EFFECTS OF ETHYLENE AND DEHYDRATION ON CUT FLOWERING STEMS OF VERTICORDIA SPP

The potential for ethylene-induced abscission among Verticordia specie s used for cut flowers (V nitens, V. chrysantha, V. plumosa, and V. de nsiflora) was studied by treating them with 2-chloroethyl-phosphonic a cid (ethephon) or exposing them to dilute ethylene gas. The possibilit y that ethylene production induced by water stress may cause flower ab scission was also investigated. Dipping in ethephon (500 or 1000 mg/L) failed to induce flower abscission in V chrysantha or V plumosa. Trea tment with ethylene (8.6 muL/L) failed to induce flower abscission in V. densiflora. Ethephon and ethylene both induced substantial flower, pedicel, and leaf abscission in V nitens. Pretreatment with silver thi osulfate prevented ethylene-induced flower abscission in V nitens. Deh ydrating stems for periods of 6, 12, 24, or 48 h at about 20-degrees-C did not induce flower abscission in either V plumosa or V nitens. Deh ydration periods of 6 and 12 h had no effect on longevity. Longer dryi ng periods (24 and 48 h) induced early loss in appearance (visual qual ity) of both species.