’ french marigold ( Tagetes patula ), ‘Prelude’ wax begonia ( Begonia × semperflorens-cultorum ), ‘Titan’ madagascar periwinkle ( Catharanthus roseus ), ‘Double Zahara’ zinnia ( Zinnia marylandica ), and ‘Wizard’ coleus ( Solenostemon scutellarioides
Brian Dintelmann, David Trinklein, and Kevin Bradley
Krishna Nemali and Marc W. van Iersel
stomatal and non-stomatal limitations to photosynthesis Plant Cell Environ. 8 95 104 Kim, J. van Iersel, M.W. 2011 Slowly developing drought stress increases photosynthetic acclimation of Catharanthus roseus Physiol. Plant. 143 166 177 Lynch, J.P. 2007a
Karen L. Panter, Steven E. Newman, and Michael J. Roll
Catharanthus roseus plants were grown in three media, each containing one of two by-products of shredded waste tires. The media were no. 1) 1 rubber*: 1 peat moss, no. 2) 1 rubber*: 1 vermiculite: 2 peat moss, and no. 3) 2 rubber*: 1 vermiculite: 1 peat moss (by volume) where rubber* indicates either 0.6 cm shredded rubber or a fibrous by-product. Control plants were grown in 1 peatmoss: 1 rockwool and 1 vermiculite: 1 peatmoss (by volume). Catharanthus roseus cv. Peppermint Cooler plants were grown for 7 weeks in 10-cm containers at a commercial Denver-area greenhouse. Data taken included plant heights, plant widths, flowers per stem, and dry weights. Visually, plants grown in the no. 2 mix, with either fiber or 0.6-cm rubber, were similar to the controls and superior to the other two mixes. Ending plant heights were similar among the two controls and no. 2 with fiber and were taller than all other combinations. Flower numbers were greater in the 1 rockwool: 1 peat moss control and no. 2 mix with fiber than any other treatment. The same was true for stem number and dry weight. Results indicate that the no. 2 mix of 1 fiber: 1 vermiculite: 2 peatmoss has potential for container crop production.
Assunta Bertaccini, Robert E. Davis, and Ing Ming Lee
A collection of mycoplasma-like organisms (MLOs) was maintained in plant tissues micropropagated in vitro. MLO-infected plants included Chrysanthemum frutescens L. with chyrsanthemum yellows disease, Gladiolus sp. L. with “germ fins,” Hydrangea macrophilla (Thunb.) DC. with virescence, Rubus fruticosus L. with rubus stunt, and periwinkle [Catharanthus roseus (L.) G. Don] singly infected by the following MLOs: Italian periwinkle virescence, chrysanthemum yellows, North American aster yellows, Italian periwinkle stunt, American periwinkle little leaf. Shoots micropropagated in vitro exhibited symptoms of little-leaf and/or abnormal proliferation of axillary shoots resulting in “witches' broom” appearance that resembled symptoms in grafttransmitted greenhouse-grown or naturally infected field-collected plants. These symptoms, typical of infection by MLOs, were not observed in micropropagated healthy shoots of the same plant species, and, compared with the healthy ones, varied with MLO strain and host plant species. Dot hybridizations with a nonradioactive cloned DNA probe provided evidence for the presence of MLOs in propagated tissues through serial subcultures.
D.M. Quinn, B.K. Behe, J.L. Witt, and R.S. Roark
Our objective was to determine heat tolerance and performance of 245 summer-flowering annual plant cultivars installed 16 Mar. 1995 in beds receiving full sun located at the E.V. Smith Research Center in Shorter, Ala. (lat. 32°30′N, long. 85°40′W). No maintenance, with the exception of one midseason pruning of petunias, was performed. Catharanthus roseus L. `Blush Cooler' had the highest mean rating (4.1 of 5.0). Salvia farinacea Benth. `Victoria Blue' and Petunia ×hybrida `Fantasy Pink' both performed well with 3.5 mean ratings. `Purple Wave', a compact spreading cultivar of P. ×hybrida, had a 3.1 mean rating, but had a 5.0 rating before pruning. We do not recommend pruning `Purple Wave'. Of the 34 marigold cultivars evaluated, Tagetes erecta L. `Antigua Mixed' had the highest mean rating. Tagetes erecta `Inca Yellow' and `Perfection Gold' tied with the second highest mean rating.
D.W. Burger, T.K. Hartz, and G.W. Forister
Seed germination and crop growth characteristics were determined for Tagetes spp. L. `Lemondrop', marigold; Catharanthus roseus Don. `Little Pinkie', vinca; Petunia hybrida Vilm. `Royalty Cherry', petunia; Dendranthema×grandiflorum (Ramat.) Kitamura `White Diamond', chrysanthemum; Pittosporum tobira Ait. `Wheeleri', sweet mock orange; Photinia ×fraseri Dress., photinia and Juniperus sabina L. `Moon Glow', juniper grown in various size containers containing blends of composted green waste (CGW) and UC Mix. Seed germination, plant height, and stem and root fresh and dry mass were lowest in unamended CGW. For most plants studied, a CGW: UC Mix blend containing at least 25% UC Mix was required for adequate growth and development. Germinating seeds and young seedlings were most adversely affected by unamended CGW. As plants grew and were transplanted into larger containers (10- and 15-cm pots, 530 and 1800 mL), they were better able to grow in media with higher CGW content.
Lyn A. Gettys and William T. Haller
‘Cocktail Whiskey’ begonia (Begonia semperflorens), ‘Sun Devil Extreme’ vinca (Catharanthus roseus), ‘Million Gold’ melampodium (Melampodium paludosum), and ‘Super Elfin’ impatiens (Impatiens walleriana) plants were irrigated with water treated with quinclorac, topramezone, imazamox, and penoxsulam to identify herbicide concentrations that cause phytotoxic effects. Plants were irrigated four times over a 10-day period with the equivalent of 0.5 inch of treated water during each irrigation and were then irrigated with tap water until they were harvested 28 days after the first herbicide treatment. Visual quality and dry weight data revealed that melampodium was the most sensitive of the bedding plants to quinclorac, imazamox, and penoxsulam, whereas vinca was the most sensitive species to topramezone. Noticeable reductions in visual quality and dry weight of melampodium were evident after exposure to 240, 580, and 10 ppb of quinclorac, imazamox, and penoxsulam, respectively, while dry weight of vinca was reduced after exposure to 110 ppb of topramezone. Current irrigation restrictions on imazamox, penoxsulam, and topramezone are adequate to minimize damage to these bedding plants if herbicide-treated waters are used for four irrigation events. However, irrigation restrictions should be established for quinclorac to prevent damage to sensitive bedding plants such as melampodium.
Robert L. Geneve and Sharon T. Kester
Early seedling growth rate can be used to estimate seed vigor for small-seeded vegetable and flower seeds. However, hand measurement of small seedlings is tedious and difficult to reproduce among analysts. Computer-aided analysis digital images of seedlings should improve accuracy and reproducibility. A flat-bed scanner fitted with base and top lighting provided high resolution images of even small-seeded species like petunia [Petunia ×hybrida `Blue Picotee' (Hort) Vilm.] and lisianthus [Eustoma grandiflorum `Mariachi Pure White' (Raf.) Shinn]. Uniform lighting was provided and images were captured and analyzed in less than 2 minutes. A clear, cellulose film was used as the germination substrate in petri dish germination assays to facilitate capturing images with a flat-bed scanner. The transparent medium permitted seedlings to be imaged without removal from the petri dish and also allowed for repeated measures of the same seedlings in order to calculate growth rate. Six species evaluated in this study included cauliflower (Brassica oleracea L., var. Botrytis), tomato (Lycopersicon esculentum Mill. `New Yorker'), pepper (Capsicum annuum L. `North Star'), impatiens [Impatiens walleriana Hook. f. `Impact Lavender'], vinca [Catharanthus roseus (L.) G. Don. `Little Bright Eye'], and marigold (Tagetes patula L. `Little Devil Flame'). For germination and early seedling growth, the cellulose film compared favorably with other standard germination media (blue blotter and germination paper) for five of the six species tested. Computer analysis of seedling length was possible for all six species and was statistically similar to hand measurements averaged for three analysts.
J.E. Barrett, R.K. Schoellhorn, C.A. Bartuska, D.G. Clark, and T.A. Nell
Uniconazole was applied as a spray to the surface of container media prior to planting bedding plant plugs. This medium spray was compared to a standard whole-plant spray applied 2 weeks after planting. For petunia (Petunia ×hybrida Vilm.) and coleus (Solenostemon scutellarioides L.) the efficacy of the medium spray was similar to the whole-plant spray. However, for impatiens (Impatiens wallerana Hook. f.) and vinca [Catharanthus roseus (L.) G. Don.] the medium spray had greater efficacy than the whole-plant spray. Increased concentrations of uniconazole in the medium spray decreased plant height; however, the effect of higher concentrations was greater in a medium with out pine bark compared to a medium with pine bark as a component. In the above experiments, uniconazole was applied in a volume of 200 mL·m-2. In a test where spray volume varied, there was a negative linear relationship between plant height and spray volume. Chemical name used: (E)-(+)-(S)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-pent-1-ane-3-ol (uniconazole).
Michael R. Evans, Andrew K. Koeser, Guihong Bi, Susmitha Nambuthiri, Robert Geneve, Sarah Taylor Lovell, and J. Ryan Stewart
Nine commercially available biocontainers and a plastic control were evaluated at Fayetteville, AR, and Crystal Springs, MS, to determine the irrigation interval and total water required to grow a crop of ‘Cooler Grape’ vinca (Catharanthus roseus) with or without the use of plastic shuttle trays. Additionally, the rate at which water passed through the container wall of each container was assessed with or without the use of a shuttle tray. Slotted rice hull, coconut fiber, peat, wood fiber, dairy manure, and straw containers were constructed with water-permeable materials or had openings in the container sidewall. Such properties increased the rate of water loss compared with more impermeable bioplastic, solid rice hull, and plastic containers. This higher rate of water loss resulted in most of the biocontainers having a shorter irrigation interval and a higher water requirement than traditional plastic containers. Placing permeable biocontainers in plastic shuttle trays reduced water loss through the container walls. However, irrigation demand for these containers was still generally higher than that of the plastic control containers.