Six weeks of continuous supplemental lighting beginning December 6 with High Pressure Sodium Lamps (69.4 watts per m2, 6.3 klx average at night) significantly reduced flower production time for aphelandra ‘Dania’ plants started November 8 in a glass greenhouse at 21°C. Six weeks of cooling at 10°C and 0.5 klx incandescent light, and a combination of 3 weeks supplemental HPS lighting and 3 weeks cooling were not effective in hastening flowering. Six weeks HPS lighting resulted in significant leaf crinkling but the plants were of acceptable commercial quality. The 6 week HPS lighting as well as the combination of 3 weeks HPS lighting and 3 weeks 10°C cooling resulted in a low percentage of blind terminal shoots.
major contribution by a number of scientists ( Bonhomme, 2000 ; Galán et al., 2001 ). In reality, several studies were conducted to determine the relationships between climate and flowering phenomena in different species ( Pellizzaro et al., 1996 ) to
, germination, and seedling stage, while others are tolerant at later stages ( Ashraf and Foolad, 2007 ; Katerji et al., 1994 ; Läuchli and Epstein, 1990 ; Niu et al., 2010b ; Pasternak et al., 1979 ). It was reported that salt stress induced early flowering
Litchi ( Litchi chinensis Sonn.) is an evergreen fruit tree widely cultivated in southeast Asia. However, unreliable flowering is a serious problem in the litchi industry. Litchi flowering is induced by low temperatures and enhanced by drought in
Flowering response in guayule (Parthenium argentatum Gray) was found to be photoperiodically induced by long days. The critical daylength for flowering was between 9.5 and 11 hours. The flowering response was the same when measured as days to first flower, node to first flower, or percentage of plants flowering. Plants flowered within 57 days of emergence under 16-hour long days or 8-hour short days, with a light interruption midway through the dark period, but did not flower under 8-hour short days. Flowering was most rapid under 20-hour days and slowed as day-lengths approached 11 hours. Flower induction occurred with exposure to as few as three 20-hour photocycles.
conditions. For that, changes in growth, water relations, and flowering characteristics were determined.
Materials and Methods
Plant material and experimental site.
Rosmarinus officinalis L. (native of the province of Murcia, southeast Spain
to promote vegetative growth in the first, or non-bearing, year. Flowering, fruit development, and harvest occur in the second, or bearing, year. Growth and development in the non-bearing year consists of ramet emergence from underground rhizomes and
-to-year variation in pistillate flowering, and subsequent cropload, is termed AB. Although AB-linked variation in pistillate flowering likely increases individual fitness in natural habitats, it is also a major impediment to greater horticultural domestication and
Seedling growth and flowering responses were examined for four Eustoma cultivars exposed to photoperiod × temperature treatments during two seedling ages. Seedlings were grown under short days (SD, 12-hour photoperiod) or long days (LD, 18-hour photoperiod) in soil at 12 or 28C from 14 to 43 days after sowing. Seedlings from each treatment were then subdivided into four lots and subjected to the same photoperiod × temperature treatments from 43 to 79 days after sowing, for a total of 16 treatments. To determine flowering response, seedlings were grown subsequently for 120 days at 22C under the same photoperiod that they received from day 43 to 79. For all cultivars and both seedling ages, seedlings were larger and had more leaves when grown at 28C rather than at 12C, but the tallest plants at flowering were from seedlings exposed to 12C. Seedlings from some treatments bolted but did not initiate visible flower buds, and some seedlings developed visible buds that later aborted, resulting in plants that did not flower by the termination of the experiment (199 days). Cultivar and interactive effects of photoperiod and temperature influenced the percentage of flowering plants. Vegetative growth and flowering responses were similar for `Yodel White', `Heidi Pink', and `Blue Lisa'. They flowered as LD plants when seedlings were grown at 12C from day 14 to 43 or day 43 to 79. Seedlings of these cultivars that were grown under SD at 28C from day 43 to 79 did not flower, regardless of photoperiod or temperature treatments from day 14 to 43. However, SD photoperiod or 28C did not decrease flowering for `GCREC-Blue'.