Table 4. Percent water use of 5 foliage plants maintained indoors under two light intensities and treated with 0.0 or 0.5 ml paclobutrazol/15 cm pot applied 12 September 1991. Percent water use compared for light and paclobutrazol treatment. Water use measured from 10 September 1991 until 2 January 1992. Epipremnum Dieffenbachia aureum Light intensity Araucaria maculata 'Golden Polyscias Radermachera ft-cz heterophylla 'Camille' Pothos' fruticosa sinica 75 65 70 58 62 51 150 100 100 100 100 100 Paclobutrazol (ml) 0.0 108 116 105 107 114 0.5 100 100 100 100 100 zPlants received light 12 hours daily from cool white fluorescent bulbs. 3 and 4). Paclobutrazol-treated 'Camille' dieffenbachia and Halevy, A. H. and B. Kessler. 1963. Increased tolerance of bean plants China doll consumed less water from reservoirs than non- to soil drought by means of growth-retarding substances. Nature treated plants (Tables 3 and 4) but, as stated above, overall 197:310-311. Hamada, M., T. Hosoki, and T. Maeda. 1990. Shoot length control of quality of dieffenbachia was adversely affected by pac tree peony (Paeonia suffruticosa) with uniconazole and paclobutrazol. lobutrazol. HortScience 25:198-200. While water consumption was influenced primarily by Latimer, J. G. 1992. Drought, paclobutrazol, abscisic acid and gibberellic light intensity, there was some evidence paclobutrazol- acid as alternatives to daminozide in tomato transplant production. J. Amer. Soc. Hort. Sci. 117:243-247. treated plants consumed less water than untreated plants. LeCain, D. R., K. A. Schekel, and R. L. Wample. 1984. The effect of There was no difference found in plant grades of pac- paclobutrazol on acclimatization of Ficus benjamina. HortScience lobutrazol-treated and non-treated foliage, with the excep 19:587 (abstract). tion of 'Camille' dieffenbachia. LeCain, D. R., K. A. Schekel, and R. L. Wample. 1986. Growth retarding effects of paclobutrazol on weeping fig. HortScience 21:1150-1152. McDaniel, G. L. 1983. Growth retardation activity of paclobutrazol on Literature Cited chrysanthemum. HortScience 18:199-200. Smith, E. F., A. V. Roberts, and J. Mottley. 1990. The preparation in vitro Barrett J. E. and T. A. Nell. 1979. Effects of growth retardants on plant of chrysanthemum for transplantation to soil. 2. Improved resistance water use. Proc. Plant Growth Regulator Working Group 6:69-74. to desiccation conferred by paclobutrazol. Plant Cell Tissue Organ Cox, C. A. and G. J. Keever. 1988. Paclobutrazol inhibits growth of Zinnia Cult. 21:133-140. and Geranium. HortScience 23:1029-1030. Swietlik, D. and S. S. Miller. 1983. The effect of paclobutrazol on growth Cox, C. A. and F. F. Whittington. 1988. Effects of paclobutrazol on height response to water stress of apple seedlings. J. Amer. Soc. Hort. Sci. and performance of aluminum plant in a simulated interior environ 108:1076-1080. ment. HortScience 23:222. Wang, Y. T. and T. M. Blessington. 1990. Growth of four tropical foliage Davis, T. D., K. Emino, W. Shurtieff, and N. Sankhla. 1985. The promise species treated with paclobutrazol or uniconazole. HortScience of paclobutrazol. Interior Landscape Industry 2(11):36-41. 25:202-204. Hagiladi, A. and A. A. Watad. 1992. Cordyline terminalis plants respond Wilkinson, R. I. and D. Richards. 1988. Influence of paclobutrazol on to foliar sprays and medium drenches of paclobutrazol. HortScience growth and flowering of Camellia X Williamsii. HortScience 23:359- 27:128-130. 360. Proc. Fla. State Hort. Soc. 105:180-182. 1992. NOTCHING AFFECTS BUD BREAK OF DRACAENA FRAGRANS 'MASSANGEANA' CANE D. B. MCCONNELL Abstract. When Dracaena fragrans (L.) Ker-Gawl is propa University of Florida, IFAS gated from cane, bud break is usually confined to the apical Department of Environmental Horticulture portion of the cane. A market niche exists for rooted cane Gainesville, FL 32611 with bud break and "head" development on the subapical portion of the cane. Notching the cane will induce bud break Maria Costa Smith but little information is available on the size, location or Costa Nursery Farms Inc. number of notches required for optimal bud break. Forty-two 22290 SW 162 Avenue 4 ft. cane sections were obtained from a commercial source Goulds, FL 33170 and divided equally into 7 different notching treatments. Plants were grown in a greenhouse for 12 weeks and bud break and "head" development were evaluated. Plants were Additional index words, foliage plant, propagation. later transferred to interior rooms under 100 ft-c for 12 hrs daily and room temperatures of 80°F for 16 weeks and leaf development of subapical "heads" was monitored. Results Florida Agricultural Experiment Station Journal Series No. N-00720. Mention or use of specific products does not imply endorsements by the showed that subapical bud break did not inhibit apical bud Institute of Food and Agricultural Sciences, University of Florida. break and apical growth did not suppress subapical growth. 180 Proc. Fla. State Hort. Soc. 105: 1992. Dracaena fragrans is a popular foliage plant that has Table 2. Average count of leaf rosettes ("heads") per identified cane re been used in interiorscapes since the turn of the century gion 22 weeks after notching treatment. (Smith and Scarborough, 1981). It is commonly propa gated from woody cane sections varying in length from 1.5 Apical Region A Region B Region C Treatment* 0-15 cm 15-45 cm 45-75 cm 75-105 cm ft to 6 ft. Commercially, containers of D. fragrans 'Mas- sangeana' canes are produced using three to five bare Nl 5 1 1 canes of different lengths per container. Growers use this N2 3 2 1 method as the cane exhibits strong apical dominance with N3 4 2 I 1 N4 bud break and subsequent growth only on the upper 15 5 1 1 N5 4 1 1 cm of the cane. The 30 to 90 cm long, whorled leaves N6 4 2 1 produced on each growing point are collectively called N7 7 0 0 0 "heads". Although D. fragrans is a monocot, it has a true vascular cambium and undergoes secondary thickening *Excluding the control, there was no significant difference between any of the treatments. (Melendro and McConnell, 1985). Previous research has shown that notching the basal portion of the cane induces tainers filled with Metro-Mix 300 (W. R. Grace & Co., root development immediately above the notch (McCon Cambridge, Mass.). nell and Melendro, 1988). This root development was attri The containers were placed in greenhouse under 70% buted to an accumulation of auxins in the vascular cam light exclusion in a completely random design with bium immediately above the notch. greenhouse heating and cooling controls set at 18°C night If basipetal flow of auxin inhibits bud break on the and 25°C day. Bud break per region and section was re cane, a notch cut in the cane would restrict this auxin flow corded 12, 18 and 22 weeks after notching. The number and permit bud break immediately below the notch. Canes of actively growing "heads" was determined on November with strategically located lateral bud break and leaf growth 11, 1989. Plants were then transferred to interior rooms would have increased commercial value and permit grow where light levels were maintained at 100 ft-c from cool ers to use fewer canes per container. However, little infor white fluorescent lamps for 12 hrs daily with air tempera mation is available on the size, location or number of tures maintained between 25-27°C. Once a month, the notches to induce bud break on the subapical portion of number of new leaves on the apical and sub-apical heads the cane. were determined until termination of the experiment on The objectives of this experiment were to determine March 15, 1990. the size, location, and number of notches for optimal bud break, to determine the ability of these buds to develop Results and Discussion "heads" and to determine if subapical "heads" continue growth under interior conditions. By the 22nd week after treatment, the number of buds that developed into leaf producing branches no longer in creased. In all cases, initial bud swelling and leaf develop Materials and Methods ment occurred 1 to 7 cm below the notch. There were no differences between any of the notching treatments and, Forty-two 4 ft. cane sections were obtained from a com excluding the basal 30 cm of canes in treatment N3, both mercial source on Feb. 9, 1989. After arrival, a 2.5 cm slice spiral and linear arrangement of notches developed at least was removed from the base of all canes and the canes were one bud break per notch (Table 2). When more than one placed basal end down in 45 cm of water and soaked over bud break per notch occurred, it was observed that the night. Each cane was partitioned into three 30 cm regions notch extended over more than one basal leaf scar. Statis beginning 15 cm below the apical end and terminating 15 tically the longer and deeper notch used for treatment N6 cm above the basal end. The regions were designated A, did not promote a greater number of bud breaks. How B, and C, starting at the apical end of the cane. Each cane ever, treatment N3 had two notches per each 30 cm cane was also delineated in 3 equal pie-shaped sections designa region and averaged two developing buds per region A ted 1, 2, or 3. Treatments were applied as listed in Table and B in the upper 60 cm of the cane. Buds in the basal 1 with all notches cut with a pruning saw. After notching, 30 cm of the cane often failed to develop further and the canes were potted in standard black plastic 3-gal con- notches in region C had less than one lateral branch per notch.