Search Results

You are looking at 41 - 50 of 62 items for

  • Author or Editor: Jianjun Chen x
Clear All Modify Search

Containerized ornamental plant production represents extremely intensive agricultural production. An average of 200,000 containers may occupy 1 acre of surface area, to which a large amount of chemical fertilizers will be applied. Because of the use of high-drainage soilless potting mixes coupled with excessive fertigation, a great amount of nutrients, particularly nitrogen and phosphorus, are leached, which increases the potential for ground and surface water contamination. Over the past 2 decades, research has been centered on developing fertigation delivery systems such as nutrient film techniques, ebb-and-flow and capillary mat systems, for reducing leaching. Relatively limited research has been conducted on improving potting medium substrates to minimize nutrient leaching. The objectives of this study were to determine the adsorption isotherm of six different zeolites to ammonium, nitrate and phosphorus, identify and incorporate desired zeolites in a peat/bark-based medium for reducing nutrient leaching in ornamental plant production. Results indicated that the zeolites possess great holding capacities for ammonium, nitrate, and phosphorus. Compared to control, ammonium leaching was reduced 70% to 90%, phosphorus 30% to 80% and nitrate 0% to 60% depending on zeolite species and quantity used per pot. Zeolite amended media caused no adverse effects on plant growth. Conversely, biomass increased significantly when compared to that of the control.

Free access

Anthurium cultivars are being produced primarily as cut-flower plants. Whether Anthurium can be used as a flowering interiorscape plant is not well documented. Therefore, five finished Anthurium cultivars were evaluated in interior acclimatization rooms under two light intensities provided by cool-white fluorescent lamps for 12 hours daily: 16 mmol·m–2·s–1 (low light) and 48 16 mmol·m–2·s–1 (high light). Temperature of the rooms was maintained at 24 °C with a relative humidity of 60%. Total number of open flowers and number of senesced flowers were recorded weekly over 5 months. In addition, plant canopy height and width and total number of leaves were measured monthly. Number of open flowers per week ranged from 1.4 to 4.7 under low light and 2.4 to 6.3 under high light. The cultivar Red Hot showed the best performance with a weekly average flower count of 4.7 under low light and 6.3 under high light. All cultivars continued to produce new leaves, ranging from one to five per month under low light and two to five leaves under high light. Leaves were dark green and shiny under the interior conditions. Growth index of `Red Hot' increased 31% under low light and 20% under high light. Results from this study demonstrate that Anthurium can continue to grow and produce flowers under interior environmental conditions. Variation among cultivars indicates that genetic potential exists for selecting improved cultivars based on interior performance.

Free access

Aglaonema is among the most popular tropical ornamental foliage plants used indoors because of its bright foliar variegation, low light and humidity tolerance, and few pests. Aglaonema, however, has been labeled as one of the most chilling-sensitive foliage plants. The dark, greasy-appearing patches on leaves injured by chilling can result in completely unsalable plants. With recent breeding activity, more and more Aglaonema cultivars have been developed and released. How new cultivars respond to chilling temperatures is, however, mostly unclear. This study was undertaken to evaluate cultivar chilling responses to identify chilling-resistant cultivars. Twenty cultivars were chilled at 1.7, 4.4, 7.2, 10, and 12.7 °C for 24 h using a detached single-leaf method and also whole-plant assay. Results indicate that great genetic variation exists among the cultivars, ranging from no injury at 1.7 °C to severe injury at 12.7 °C. A popular cultivar, Silver Queen, is the most sensitive, while the cultivar Stars is the most resistant. There was also a chilling response difference based on leaf maturity. Young leaves showed less injury than did either mature or old leaves. In addition, there was a significant correlation between the single-leaf and whole-plant assay for chilling resistance in Aglaonema'; the single leaf assay could be particularly useful for a quick test.

Free access

Peace lily (Spathiphyllum Schott) is one of the most popular tropical ornamental foliage plants and is used worldwide for interiorscaping. However, little information is available on the genetic relationships of cultivars. Using amplified fragment length polymorphism (AFLP) markers with near-infrared fluorescence-labeled primers, this study analyzed genetic relatedness of 63 commercial cultivars and breeding lines. Forty-eight EcoRI + 2/MseI + 3 primer set combinations were initially screened, from which six primer sets were selected and used in this investigation. All cultivars were clearly differentiated by their AFLP fingerprints, and the relationships were analyzed using the unweighted pair-group method of arithmetic average cluster analysis (UPGMA). The 63 cultivars were divided into four clusters. All commercial cultivars or breeding lines resulted from crosses of some of the cultivars, a total of 45, were positioned in cluster I with Jaccard's similarity coefficients between 0.61 and 0.88. There was only one cultivar in cluster II. Cluster III contained 16 cultivars; they are either species or breeding lines generated from interspecific hybridization. Cluster IV had one unknown species. This study provides genetic evidence as to why cultivars from cluster I and III are not readily crossable because the Jaccard's similarity coefficient between the two clusters was only 0.35. Results also indicate that commercial cultivars are genetically close. Strategies for increasing genetic diversity of cultivated peace lily should be sought for future breeding efforts.

Free access

Potted anthurium is becoming an important indoor flowering foliage plant because of its unique attractive appearance and continuous growth and flowering under interior conditions. However, an interior environment, with controlled optimal temperatures and relative humidity and living plants, is an ideal niche for pest development. Pests such as thrips and two-spotted spider mite on Anthurium have been great challenges to the interiorscape industry because many pesticides have been rigorously restricted for interior use. Thus, exploiting the genetic potential of cultivar resistance may be the best approach for the control of these pests. In this study, eight of the most popular Anthurium cultivars were evaluated for their resistance to a natural infestation of thrips (Hercinothrips femoralis) and two-spotted spider mite (Tetranychus urticae) under three light levels: 4, 8, and 16 μmol·m-2·s-1, temperatures of 23.8 to 26.7 °C and a relative humidity of 60%. Results indicated that significant resistant differences exist among cultivars. The cultivars most resistant to thrips were not the most resistant to mite and vice versa. Cultivars that exhibited moderate resistance to thrips were also moderately resistant to mite. Low light intensity appeared to be a factor influencing thrips infestation since control plants that grew under a light intensity of 200 μmol·m-2·s-1 had no observed thrips damage. On the other hand, two-spotted spider mite infestation was not influenced by light intensity.

Free access

This study established a new method for regenerating Anthurium andraeanum Lind. and evaluated effects of different wavelengths from light-emitting diodes (LEDs) on rooting and growth of adventitious shoots. Callus occurred in leaf explants of A. andraeanum ‘Alabama’ and ‘Sierra’ cultured on a modified Murashige and Skoog (MS) basal medium supplemented with four concentrations of N-phenyl-N′-1,2,3-thiadiazol-5-ylurea (TDZ). Adventitious shoots were induced from callus pieces (≈1 cm3) cultured on the modified MS medium containing 6-benzyladenine (BA) with kinetin (KN), BA, and/or KN with 3-indolebutyric acid (IBA) or α-naphthalene acetic acid (NAA). Results showed that 1.82 μM TDZ induced 83.3% and 77.8% of leaf explants of ‘Alabama’ and ‘Sierra’ to produce callus and 24.9 and 24.7 adventitious shoots were produced per callus piece of ‘Alabama’ and ‘Sierra’ cultured on the modified MS medium containing 0.89 μM BA, 2.32 μM KN, and 0.98 μM IBA, respectively. Adventitious shoots were cut and rooted in the modified MS medium containing 0.98 μM IBA and grown under the same light level but with different light qualities. All adventitious shoots rooted; root numbers, root lengths, root fresh and dry weights, and leaf area of plantlets grown under red plus blue light were comparable to those grown under conventional fluorescent white light. Shoot height was the greatest in monochromic blue light followed by red light. Shoot fresh and dry weights of plantlets grown under red plus blue light, however, were significantly greater than those grown under the other light qualities. Plantlets grown under red plus blue light had 22.7% greater total dry weight and more balanced root-to-shoot ratio than those grown under fluorescent white light. These results suggested the use of complex of red plus blue LED could be an option for improving growth of A. andraeanum plantlets in vitro.

Free access

Adenium obesum (Forssk.), Roem. & Schult. has been increasingly produced as a flowering potted plant; however, there is no information regarding its tissue mineral composition. This study evaluated plant performance of A. obesum ‘Red’ grown in two container sizes and under four rates of a controlled-release fertilizer. Nutrient concentrations in flowers, leaves, stems, and roots were analyzed. Results showed that canopy height and width, stem caliper, top and root dry weights, and average flower count of A. obesum ‘Red’ increased linearly with the increased rate of fertilizer regardless of pot size. Tissue analysis indicated that nitrogen (N), phosphorus (P), and potassium (K) concentrations were lower in all organs compared with those reported for other ornamental potted plants such as Bouvardia Salisb., Euphorbia L., Rhododendron L., and Rosa L. The lower levels of tissue N and P accompanied with higher dry matter accumulation suggest that A. obesum ‘Red’ is efficient in use of N and P. The low tissue K levels were largely attributed to sodium (Na) substitution for K. Leaf K and Na concentrations were almost equal except at the highest fertilizer treatment in 1.25-L pots and the last two higher treatments in 3.0-L pots. The levels of other mineral elements were comparable to those of other reported ornamental potted plants. To produce high-quality plants in 1.25-L pots, Adenium ‘Red’ should be fertilized with 1.08 g N per liter of potting mix. For plants grown in 3.0-L pots, N rates of 0.36 g or 0.72 g per liter of potting mix would be recommended with a preference for 0.36 g.

Free access

Three composts, derived from municipal solid waste with biosolids, yard trimmings, and yard trimmings with biosolids, were mixed by volume with sphagnum peat and pine bark to formulate 12 substrates. After characterizing physical and chemical properties, the substrates, along with a control, were used for rooting single eye cuttings of pothos (Epipremnum aureum) and terminal cuttings of maranta (Maranta leuconeura) and schefflera (Schefflera arboricola) in enclosed polyethylene tents. All cuttings initiated roots with no significant difference in root numbers per cutting 14 days after sticking, but root lengths 21 days and root-ball coverage ratings 45 days after sticking were significantly affected by substrates. Five of 12 compost-formulated substrates resulted in root lengths of cuttings equal to or longer than the control. In addition to desirable physical properties such as bulk density, total porosity, and air space, common chemical characteristics of the five substrates included low concentration of mineral elements, initial electrical conductivity ≤3.0 dS·m-1 based on the pour through extraction method, and pH between 3.8 to 5.0. The five substrates were formulated by combining composted municipal solid waste with biosolids or yard trimmings with biosolids volumetrically at 20% or less or composted yard trimmings at 50% or less with equal volumes of sphagnum peat and pine bark.

Full access

Fire flash (Chlorophytum amaniense), a member of Liliaceae, is attracting considerable attention in the foliage plant industry as a new addition for interior plantscaping. Coral-colored petioles and midribs contrasting with dark green leaves make it a sought after specimen. Originally collected from rainforests of eastern Africa in 1902, it has remained largely obscure for a century. Recently, studies on fire flash's propagation, production, and interiorscape performance have been completed. This report presents relevant botanical information and the results of our 4-year evaluation of this plant. Fire flash can be propagated through seed, division, or tissue culture and produced as a potted foliage plant under light levels from 114 to 228 μmol·m–2·s–1 and temperatures from 18 to 32 °C. Finished plants after being placed in building interiors are able to maintain their aesthetic appearances under a light level as low as 8 μmol·m–2·s–1 for 8 months or longer.

Full access