Nitrate nitrogen has been recommended as the best form of nitrogen for the production of poinsettia while ammonium and urea have been reported to be deleterious to poinsettia growth. Recent studies have indicated that lower nitrogen and leaching levels will produce quality poinsettias. Poinsettias were grown with 21–7–7 Acid Special (9.15% NH4, 11.85% urea), 20–10–20 Peat-lite Special (7.77% NH4, 12.23% NO3), 15-220 plus Ca and Mg (1.5% NH4, 12.7% NO3, 0.8% urea), and 15–5–15 Excel CalMag (1.2% NH4, 11.75% NO3, 2.05% urea) applied at 200 mg·L-1. Plants were fertigated by drip irrigation with zero leachate. There were no significant differences between fertilizer treatments for plant height, width, bloom diameter, and dry weight. Electrical conductivity and pH did vary significantly between treatments; however, this did not effect plant growth. Thus, by using lower nitrogen levels and zero leachate, quality poinsettias can be grown with commercial fertilizers high in ammonium/urea or high in nitrate nitrogen, or ammonium and nitrate in combination.
Jeff S. Kuehny, Patricia C. Branch, and Felix J. Landry
Jeff S. Kuehny, Aaron Painter, and Patricia C. Branch
Eight bedding plant species were grown from plugs obtained from two sources. The plugs were transplanted into jumbo six packs and sprayed with a solution of chlormequat/daminozide with concentrations of 1000/800, 1250/1250, or 1500/5000 mg·L-1 when new growth was ≈5 cm in height or width. Three different species were grown in the fall (Dianthus chinensis L., `Telstar Mix', Petunia ×hybrida Hort. Vilm.-Andr., `Dreams Red', and Viola ×wittrockiana Gams., `Bingo Blue'), winter [Antirrhinum majus L., `Tahiti Mix', Matthiola incana (L.) R. Br., `Midget Red', and P. × hybrida, `Dreams Mix'], and spring [Catharanthus roseus (L.) G. Don, `Cooler Pink', Salvia splendens F. Sellow ex Roem. & Schult., `Empire Red', and Begonia ×semperflorens-cultorum Hort., `Cocktail Mix']. The treatments significantly reduced finished plant size of all species for each season. There was a significant difference in finish size between sources for Dianthus, Antirrhinum, Matthiola, Catharanthus, Salvia, and Begonia. The efficacy of chlormequat/daminozide also differed for each source of Dianthus, Matthiola, and Begonia, but the treatments minimized the differences in finish size between sources for Petunia and Viola. Chemical names used: (2-chlorethyl) trimethylammonium chloride (chlormequat); (N-dimethylaminosuccinamic acid) (daminozide).
Don C. Elfving and Dwayne B. Visser
The height above the bud union at which induced feathers develop on fruit trees in the nursery is an important determinant of tree quality for an intended market. The bioregulators cyclanilide (CYC; Bayer Environmental Science, Research Triangle Park, NC) and a proprietary formulation of 6-benzyladenine and gibberellins A4 and A7 (Promalin [PR]; Valent BioSciences, Walnut Creek, CA) affected the final height above the union of the lowest induced sylleptic shoot (feather) differently in apple and sweet cherry trees in the nursery. In apple, both products resulted in the lowest induced feather developing at approximately 4 to 20 cm below the height of the central leader shoot tip at the time of bioregulator application. In sweet cherry, the lowest induced feather typically originated starting approximately 2 to 20 cm above the central leader shoot tip height at the time of bioregulator application. Nursery tree height can serve as a suitable criterion for timing bioregulator applications to obtain feathers starting within a specific range of height above the bud union as long as species-specific feathering response characteristics are taken into account. Chemical names used: 1-(2,4-dichlorophenylaminocarbonyl)-cyclopropane carboxylic acid (Cyclanilide), N-(phenylmethyl)-1H-purine-6-amine + gibberellins A4A7 (Promalin), polyoxyethylenepolypropoxypropanol, dihydroxypropane, 2-butoxyethanol (Regulaid).
Jeff S. Kuehny, Patricia C. Branch, Gordon E. Holcomb, and Wen-Chy Chang
Dimethyl ammonium chloride (DAC, `Triathlon'), sodium hypochlorite, formaldehyde, and streptomycin (`Agri-mycin 17') were used as dips to treat Zantedeschia rehmannii superba Engl., Zantedeschia elliotiana ×maculata (Hook.) Engl., and Zantedeschia albomaculata (W.Wats.) Baill. rhizomes to control Erwinia soft rot. A 30 min 200 ppm (mg·L−1) streptomycin dip provided the best control of Erwinia soft rot for all three Zantedeschia species and a 1-hour 10% formaldehyde dip provided the second best control of inoculated rhizomes. Rhizomes inoculated with Erwinia required more days to emerge. Chemical treatments did not affect days to emergence or final plant growth.
Scarlett L. Walker and Richard L. Harkess
36 COLLEGIATE BRANCH ORAL SESSION (Abstr. 793–x803)
Renee Timmermann and M.A.L. Smith
32 ORAL SESSION (Abstr. 375-382) COLLEGIATE BRANCH FORUM I
Long Ma, Kevin E. Kenworthy, Huangjun Lu, and Ronald Cherry
of the leaf. It has a boat-shaped leaf tip and flattened leaf sheath ( Bruneau et al., 2008 ). The seed head of common carpetgrass usually includes two to three raceme-type branches with the upper two branches approximate and the third remote ( Heath
Gilles Galopin, Sandrine Codarin, Jean-Daniel Viemont, and Philippe Morel
. Fertile florets are differentiated as of the second branching order in terminal position. Sterile florets are differentiated later and are located on the secondary branchings of the dichasium. Inflorescence development takes place over two growing
Ellen Thompson, Bernadine C. Strik, John R. Clark, and Chad E. Finn
primocanes and winter pruning of floricanes. Tipping the upper portion of the primocane in early summer removes apical dominance and encourages branching. Similarly, soft-tipping (removing the upper 2 to 5 cm) primocane-fruiting types in early summer may be a
Benjamin D. Toft, Mobashwer M. Alam, John D. Wilkie, and Bruce L. Topp
Lespinasse, 2001 ; Sherif, 2013 ), and increased branching can improve early flowering of mango due to availability of terminal shoots ( Oosthuyse and Jacobs, 1995 ), although similar relationships are unclear for macadamia. Therefore, it is necessary to