Abstract
Net photosynthesis, as measured by dry matter changes, was reduced following the dark periods when foliage plants were grown in extended, alternate dark-light cycles. Longer dark periods resulted in greater reduction; however, recovery was observed if the light duration was increased. No visual quality reduction was observed in Tradescantia fluminensis Veil and Asparagus setaceus Jessop which was grown under 14 days light: 14 days dark cycles for 84 days. Similarly, the quality of mature leaves and stems of Philodendron scandens Subsp. oxycardium (Schott) Bunt grown under 24 days dark: 24 days light cycles for 96 days was not impaired; however, new shoots and leaves were abnormal. Dry matter partitioning of Philodendron was affected by light conditions and growth activity. In plants with no active growth, the dry weight of leaves, stems, and roots was increased under adequate light condition and decreased under darkness. Stems were stronger sinks than leaves. In all treatments, when new shoots started their active growth, they became the main carbohydrate sinks with a concomitant reduction of weight of the mature organs. Reduction in percent dry matter following the lowering of the light intensity was observed. Determining and measuring the critical percent dry matter at which plant injury occurs are suggested as practical methods to evaluate the plant’s condition and how it may respond during and after the marketing period.
Abstract
Foliage plants were placed in chambers receiving no light for various time periods after receiving variable fertilizer and light treatments during production. Three foliage plants (Brassaia actinophylla Endl, Philodendron scandens oxycardium (Schott) Bunt, and Aphelandra squarrosa Nees ‘Dania’) in total darkness for 6 days suffered no loss in quality, but Ficus benjamina L. dropped slightly more leaves as length of time in dark storage increased. High light and fertilizer levels during production of F. benjamina increased leaf drop after dark storage.
prolonged darkness, dry mass and %DM of storage roots were lower among plants in response to the main effect of prolonged darkness ( Table 1 ). Plants exposed to prolonged darkness produced 25% lower fibrous root dry mass ( Table 1 ), but similar foliage
produced 36% to 44% shorter plant height, 24% to 29% smaller plant diameter, and 1-d delayed flowering ( Table 2 ). Use of 1.0 mg paclobutrazol produced plants with dark green foliage and delayed first and second wilting by 3.9 and 2.0 d, respectively
foliage color. In addition, they were selected based on foliage color and leaf morphologies. For geranium ‘Black Velvet’, leaves are reniform and vary from almost “zoned” to completely solid red to dark maroon centers with a contrasting green leaf margin
:blue light for 5 d was significantly lower (resulting in darker foliage) than those under the control ( Table 3 ). As exposure to EOP SL increased from 3 to 14 d, L* values decreased for plants under LED treatments providing 100 µmol·m −2 ·s −1 . Additionally
. Reynard (1956) reported that dark-pigmented fruit and/or foliage types were found in a rogue plant of an unknown line at a Campbell’s farm (Riverton, NJ) and called this ‘Webb’s Special’ (‘Black Queen’). From this line, at least two genes, high pigment 1
, it is also resistant to powdery mildew ( Arnold, 2008 ; Cabrera, 2004 ; Dirr, 2009 ). A cross of Red Rocket ® crepe myrtle (‘Whit IV’) and ‘Sarah’s Favorite’ crepe myrtle resulted in a crepe myrtle with dark foliage, ‘Chocolate Mocha’ ( Knight and
magnolia ( Magnolia denudata ) or lily magnolia ( Magnolia liliflora )] can offer yellow flower color and a range of tree sizes and shapes. Most American magnolias bloom with the foliage, which means a late spring–summer bloom; whereas, the Chinese
,” referring to their onion-like bulbs, which are inedible ( Qin et al., 2003 ). The plants have ornamental value because of their beautiful flowers and attractive foliage ( Zhang and Cao, 2001 ) and have been used as potted and landscape plants for several