Abstract
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.
, 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
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
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
Strawberry cultivars traditionally have been classified into photoperiodic response groups for flowering. June bearers are defined as facultative short-day (SD) plants ( Darrow, 1936 ), everbearers are classified as long-day plants (LD) ( Darrow
Abstract
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
The developmental stage at which the shoot primary axis meristem (PAM) of the `Hass' avocado (Persea americana Mill.) is committed to flowering was determined. Three-year-old trees were subjected to low-temperature (LT) treatments at 10/7 °C day/night with a 10-h photoperiod for 1 to 4 weeks followed by 25/20 °C day/night at the same photoperiod. Before LT treatment, apical buds of mature vegetative shoots consisted of a convex PAM with two lateral secondary axis inflorescence meristems lacking apical bracts each associated with an inflorescence bract. Apical buds did not change anatomically during LT treatment. However, the 3- and 4-week LT treatments resulted in inflorescences at 17% and 83% of apical buds, respectively. Trees receiving 2 weeks or less LT, including controls maintained at 25/20 °C, produced only vegetative shoots. Apical buds of 2-year-old trees receiving 3 weeks at 10/7 °C plus 1 week at 20/15 °C produced 100% inflorescences. GA3(100 mg·L-1) applied to buds 2 or 4 weeks after initiation of this LT treatment did not reduce the number of inflorescences that developed. `Hass' avocado apical buds were fully committed to flowering after 4 weeks of LT, but were not distinguishable anatomically from those that were not committed to flowering.