A Lycopersicon esculentum Mill. (tomato) cDNA clone with high similarity to a Nicotiana plumbaginifolia Viv. (tobacco) cytochrome P450 gene was isolated using 5' and 3' rapid amplification of cDNA ends (RACE). The isolated cDNA (GenBank Accession No. AF249329) has an open reading frame of 1494 base pairs (bp) and encodes a protein of 498 amino acids with 75% identity to the N. plumbaginifolia cytochrome P450 (CYP72A2) and 45% to a Catharanthus roseus G. Don (Madagaskar periwinkle) CYP72A1 protein sequence. By Southern-blot analysis, one or two highly homologous genes were detected in the L. esculentum genome. Expression of the cloned P450 gene was regulated by circadian rhythm and enhanced by wounding. Leaf transcripts were detected in the light but not dark. Highest transcript levels were observed 3 hours after mechanical wounding. No increase in expression was seen in response to applications of zeatin as with the N. plumbaginifolia gene. Of the tissues analyzed, shoot tips and young leaves and fruit had the highest detectable transcript levels. Attempts to transform more than 1400 cotyledon explants of L. esculentum with sense or antisense CYP72A2 gene constructs produced no transgenic plants.
Grzegorz Bartoszewski, Cesar V. Mujer, Katarzyna Niemirowicz-Szczytt and Ann C. Smigocki
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.
James E. Faust and Royal D. Heins
An energy-balance model is described that predicts vinca (Catharanthus roseus L.) shoot-tip temperature using four environmental measurements: solar radiation and dry bulb, wet bulb, and glazing material temperature. The time and magnitude of the differences between shoot-tip and air temperature were determined in greenhouses maintained at air temperatures of 15, 20, 25, 30, or 35 °C. At night, shoot-tip temperature was always below air temperature. Shoot-tip temperature decreased from 0.5 to 5 °C below air temperature as greenhouse glass temperature decreased from 2 to 15 °C below air temperature. During the photoperiod under low vapor-pressure deficit (VPD) and low air temperature, shoot-tip temperature increased ≈4 °C as solar radiation increased from 0 to 600 W·m-2. Under high VPD and high air temperature, shoot-tip temperature initially decreased 1 to 2 °C at sunrise, then increased later in the morning as solar radiation increased. The model predicted shoot-tip temperatures within ±1 °C of 81% of the observed 1-hour average shoot-tip temperatures. The model was used to simulate shoot-tip temperatures under different VPD, solar radiation, and air temperatures. Since the rate of leaf and flower development are influenced by the temperature of the meristematic tissues, a model of shoot-tip temperature will be a valuable tool to predict plant development in greenhouses and to control the greenhouse environment based on a plant temperature setpoint.
Christopher J. Currey, Roberto G. Lopez and Neil S. Mattson
Energy accounts for one of the largest costs in commercial greenhouse (GH) production of annual bedding plants. Therefore, many bedding plant producers are searching for energy efficient production methods. Our objectives were to quantify the impact of growing annual bedding plants in an unheated high tunnel (HT) compared with a traditional heated GH environment at two northern latitudes. Ten popular bedding plants [angelonia (Angelonia angustifolia), vinca (Catharanthus roseus), celosia (Celosia argentea), dianthus (Dianthus chinensis), geranium (Pelargonium ×hortorum), petunia (Petunia ×hybrida), french marigold (Tagetes patula), viola (Viola ×cornuta), snapdragon (Antirrhinum majus), and osteospermum (Osteospermum ecklonis)] were grown both in an unheated HT and a glass-glazed GH with an 18 °C temperature set point beginning on 1 Apr. 2011 at both Cornell University (Ithaca, NY) and Purdue University (West Lafayette, IN). Although seven of the species exhibited a delay in flowering in the HT as compared with the heated GH, there were no differences in days to flower (DTF) for geranium, osteospermum, and viola grown at Cornell and viola at Purdue. The remaining species exhibited delays in flowering in the HT environment, which varied based on species. At Purdue, several species were lost because of a cold temperature event necessitating a second planting. For the second planting, osteospermum was the only species grown that flowered significantly later in the HT; 7 days later than the GH-grown plants. Production of cold-tolerant annuals in unheated or minimally heated HTs appears to be a viable alternative for commercial producers aiming to reduce energy costs.
Lizzette Gonzalez*, Juan C. Vazquez and Maria del C. Libran
Municipal solid waste compost (MSW) can be used as an effective substrate for ornamental plant production as an alternative to peat. In a previous study a mix with peat, perlite, and vermiculite (1:1:1 per volume) was used along MSW compost at 1:1 per volume ratio as a growing substrate for Catharanthus roseus, providing nitrogen (N) for adequate plant growth. This study will focus in determining if MSW provides adequate amounts of N and Phosphorous (P) for Anthurium pot plant production, reducing the use of fertilizers and nutrient loss to the environment. Plants were fertilized at 0, 100, 150, and 200 ppm N using a 20-10-20 soluble fertilizer. Chemical characterization of leachates collected from plants grown in substrates with or without MSW, to determine possible nutrient run off. Tissue analysis for N and P content was conducted to determine absorption. Our results shows an increase in NH4 -N, NO3 -N and soluble P in leachates as the fertilizer level increased. Higher NO3 -N content in leachates was observed in treatments with MSW. Higher P concentrations were observed in leachates from substrate without MSW. Weeks after, 62% of the plants grown in MSW were dead; the surviving plants had less biomass, but similar N content in leaf and root tissues than plants grown without MSW. Higher P content in tissues was observed in fertilized plants grown without MSW. The MSW was a nutrient source for the plants, but further studies should be conducted for optimum use of MSW as a component of growing substrate.
Keri L. Paridon, Norman Winter, William B. Evans and Guihong Bi
Landscape trials were conducted to evaluate 235 cultivars within 66 species in central Mississippi. All entries were grown from seed or vegetatively propagated material. Raised landscape beds were prepared using accepted regional methods. Planting into beds began on 4 April and was completed on 20 April. Plants were given an overall rating based on insect resistance, disease resistance, vigor, flowering, and foliage color. Each cultivar was rated bimonthly until early August when pruning or termination was necessary, depending on each cultivar, at which time rating frequency became once a month through the first freeze. The rating range was 0 to 5, where 5 is optimum and 0 is death. Height (cm) was measured for each cultivar at the same intervals as performance ratings. Heights were recorded to show the average height of each cultivar. No herbicides were applied; handweeding controlled weeds. No insecticides were applied to plants with the exception of the hibiscus where there was severe pressure from sawfly larva. In 2005 central Mississippi experienced a very hot and dry summer. Strong winds and heavy rains in late August and early September associated with Hurricanes Katrina and Rita took their toll on the trial, especially many of the taller cultivars. The top performing cultivars for 2005 were `Intensia Lilac Rose' phlox (Phlox ×), Proven Winners; `Intensia Neon Pink' phlox (Phlox ×), Proven Winners; `Elliottii Wind Dancer' grass (Eragrostis curvula), Pan American Seed; `Intensia Lavender Glow' phlox (Phlox ×), Proven Winners; `Dolce Licorice' heuchera (Heuchera ×), Proven Winners; `Diamond Frost' euphorbia (Euphorbia ×), Proven Winners; `Gold Flake' mecardonia (Mecardonia ×), Proven Winners; `Titan Polka Dot' annual vinca (Catharanthus roseus), Ball Seed; `Sun Fan' scaevola (Scaevola aemula), Proven Winners; `Golden Delicious' salvia (Salvia elegans), Proven Winners.
Michael R. Evans
Two grades of ground bovine bone were evaluated as potential alternatives to perlite in horticultural substrates. The bulk density of small and large bone-amended substrates was significantly higher than equivalent perlite-amended substrates. Large and small bone increased the air-filled pore space of sphagnum peat. However, at 10% and 20% (v/v), neither size of bone resulted in as high an air-filled pore space as equivalent amounts of perlite. At 30% and 40%, incorporation of small bone resulted in a similar air-filled pore space as incorporation of equivalent amounts of perlite, and incorporation of large bone resulted in a higher air-filled pore space than incorporation of equivalent amounts of perlite. Water-filled pore space and water-holding capacities of substrates were inversely related to air-filled pore space. When placed in a moist substrate, mineral elements within the bone were able to leach into the substrate over time. Substrates amended with 40% large and small bone had significantly higher concentrations of ammonium (NH4 +), phosphorus (P), potassium (K), calcium (Ca), sodium (Na), and chloride (Cl-) than the 40% perlite-containing substrates. Substrates amended with 40% large bone had similar concentrations of magnesium (Mg), sulfur (S), iron (Fe), and copper (Cu) while substrates amended with 40% small bone had higher levels of these elements than perlite-amended substrates. Substrate concentrations of nitrate (NO3 -), manganese (Mn), zinc (Zn), and boron (B) were not different among the substrates after 4 weeks in the greenhouse. The pH, electrical conductivity (EC) and NH4 + levels of bone-amended substrates increased to levels significantly higher than recommended and resulted in rapid mortality of `Orbit Cardinal' geranium (Pelargonium × hortorum), `Cooler Blush' vinca (Catharanthus roseus), and `Dazzler Rose Star' impatiens (Impatiens walleriana) plants grown in bone-amended substrates. Therefore, ground bovine bone was not a feasible alternative to perlite for use in horticultural substrates.
Michael R. Evans
Plant growth was evaluated in substrates containing varying proportions of processed poultry feather fiber (feather fiber). `Cooler Blush' vinca (Catharanthus roseus) and `Orbit Cardinal' geranium (Pelargonium × hortorum) dry shoot and dry root weights were not significantly different among plants grown in sphagnum-peat-based and perlite-based substrates containing 0% to 30% feather fiber. `Pineapple Queen' coleus (Coleus blumei) dry shoot weights were not significantly different among plants grown in substrates containing 0% to 50% feather fiber. Coleus dry root weights were not significantly different among the substrates containing 0% to 40% feather fiber. `Better Boy' tomato (Lycopersicon esculentum) dry shoot weights were not significantly different among the substrates containing 0% to 30% feather fiber. Tomato dry root weights were not significantly different among the substrates containing 0% to 30% feather fiber, but tomato grown in substrates containing 40% to 60% feather fiber had significantly lower dry root weights than tomato grown in substrates containing 0% to 30% feather fiber. `Salad Bush' cucumber (Cucumis sativus) dry shoot and dry root weights were not significantly different between plants grown in 0% to 50% feather fiber, but those gown in substrates containing 60% feather fiber had significantly lower dry shoot weights than those grown in substrates containing 0% feather fiber. Dry shoot and root weights of coleus and tomato grown in SB-300 substrate amended with 20% or 30% feather fiber were not significantly different from coleus and tomato grown in SB-300 without feather fiber. Dry shoot and dry root weights of coleus and tomato were significantly lower for plants grown in SB-300 amended with 40% feather fiber than for plants grown in SB-300 without feather fiber. For all species tested, plants grown in substrates containing up to 30% feather fiber were not significantly different from those grown in substrates containing 0% feather fiber and were of marketable qualities.
Robert D. Wright, Brian E. Jackson, Michael C. Barnes and Jake F. Browder
The objective of this study was to evaluate the landscape performance of annual bedding plants grown in a ground pine tree substrate (PTS) produced from loblolly pine trees (Pinus taeda) or in ground pine bark (PB) when transplanted into the landscape and grown at three different fertilizer rates. Begonia (Begonia ×semperflorens-cultorum) ‘Cocktail Vodka’, coleus (Solenostemen scutellarioides) ‘Kingswood Torch’, impatiens (Impatiens walleriana) ‘Dazzler White’, marigold (Tagetes erecta) ‘Bonanza Yellow’, petunia (Petunia ×hybrid) ‘Wave Purple’, salvia (Salvia splendens) ‘Red Hot Sally’, and vinca (Catharanthus roseus) ‘Cooler Pink’ were evaluated in 2005, and begonia ‘Cocktail Whiskey’, marigold ‘Inca Gold’, salvia ‘Red Hot Sally’, and vinca ‘Cooler Pink’ were evaluated in 2006 and 2007. Landscape fertilizer rates were 1 lb/1000 ft2 nitrogen (N) in 2005 and 0, 1, and 2 lb/1000 ft2 N in 2006 and 2007. Visual observations throughout each year indicated that all species, whether grown in PTS or PB, had comparable foliage quality in the landscape trial beds during the growing period. With few exceptions, dry weight and plant size for all species increased with increasing fertilizer additions, regardless of the substrate in which the plants were grown. For the unfertilized treatment, when comparing plant dry weight between PB and PTS for each species and for each year (eight comparisons), PTS-grown plant dry weight was less than PB-grown plants in three out of the eight comparisons. However, there were fewer differences in plant dry weight between PTS- and PB-grown plants when fertilizer was applied (PTS-grown plants were smaller than PB-grown plants in only 2 of the 16 comparisons: four species, two fertilizer rates, and 2 years), indicating that N immobilization may be somewhat of an issue, but not to the extent expected. Therefore, the utilization of PTS as a substrate for the production of landscape annuals may be acceptable in the context of landscape performance.
Wesley C. Randall and Roberto G. Lopez
To produce uniform, compact, and high-quality annual bedding plant seedlings in late winter through early spring, growers in northern latitudes must use supplemental lighting (SL) to achieve a photosynthetic daily light integral (DLI) of 10 to 12 mol·m−2·d−1. Alternatively, new lighting technologies may be used for sole-source photosynthetic lighting (SSL) to grow seedlings in an indoor high-density multilayer controlled environment. The objective of this study was to compare seedlings grown under low greenhouse ambient light (AL) to those grown under SL or SSL with a similar DLI. On hypocotyl emergence, seedlings of vinca (Catharanthus roseus), impatiens (Impatiens walleriana), geranium (Pelargonium ×hortorum), petunia (Petunia ×hybrida), and French marigold (Tagetes patula) were placed in a greenhouse under AL or AL plus SL delivering a photosynthetic photon flux (PPF) of 70 µmol·m−2·s–1 for 16 hours, or under multilayer SSL delivering a PPF of 185 µmol·m−2·s–1 for 16 hours in a walk-in growth chamber. Supplemental lighting consisted of high-pressure sodium (HPS) lamps or high-intensity light-emitting diode (LED) arrays with a red:blue light ratio (400–700 nm; %) of 87:13, and SSL consisted of LED arrays providing a red:blue light ratio (%) of 87:13 or 70:30. Root and shoot dry mass, stem diameter, relative chlorophyll content, and the quality index (a quantitative measurement of quality) of most species were generally greater under SSL and SL than under AL. In addition, height of geranium, petunia, and marigold was 5% to 26%, 62% to 79%, and 7% to 19% shorter, respectively, for seedlings grown under SSL compared with those under AL and SL. With the exception of impatiens, time to flower was similar or hastened for all species grown under SL or SSL compared with AL. Seedlings grown under SSL were of similar or greater quality compared with those under SL; indicating that LED SSL could be used as an alternative to traditional greenhouse seedling production.