Flowering in Senecio cruentus D.C. 'Hansa' influenced by plant growth regulators

The florists' cineraria, Senecio cruentus DC. 'Hansa,' was treated with specific plant growth regulating chemicals to stimulate flowering without vernalization. Some experimental plants received four weekly foliar sprays of: (1) the growth retardant 2-chloroethyl-trimethylammonium chloride (CCC, cycocel, chlormequat); (2) the cytokinin N-6 benzyl-adenine (BA); (3) the cytokinin kinetin; and (4) the auxin naphthaleneacetic acid (NAA). Other plants received two weekly treatments of one growth regulator followed by two treatments with another as follows: (1) the gibberellin GA₇, with CCC, or BA, or NAA; (2) CCC with NAA; (3) kinetin with GA₇; and (4) NAA with BA. Control plants were sprayed: (1) twice with GA₇; or (2) four times with distilled water. Growth regulating chemicals did not replace vernalization. The time elapsing between initiation and anthesis was shortened by treatment with two distinct growth regulating chemicals. The application of GA₇ (10 mg/l) followed with either CCC (2000 mg/l) or BA (50 or 100 mg/l) resulted in 75-80% of the test plants forming flower buds in an average of 163 days. The quality of the plants treated with GA₇ and BA was poor; however, those treated with GA₇ and CCC were of high quality. This suggests that flowering can be achieved even without vernalization within the time recommended for commercial flowering during all but the hottest months.