Effects of Ethrel on the Growth and Flower Formation in Pot Chrysanthemums

Abstract

Ethrel was sprayed at 2, 000 ppm concentration on pinched and unpinched plants of pot chrysanthemum cultivar `Jack Straw' in early vegetative stage. Results showed a reduced plant height, shortening of internode leading to rosette formation, increased number of 'new shoots, almost complete prevention of flower bud formation and temporary damage and atrophy of leaves in Ethrel sprayed plants. When applied as soil drench at the above concentration, the responses were almost the same but poorer compared to spray application.

Variation in the effects of ethephon on flowering and extension growth in chrysanthemum as a function of temperature, season, and genetics

“…The ethephon we applied resulted in the release of ethylene (Figure 1), reduced internode elongation, delayed flowering, suppressed flowering, and induced rosette formation, as reported previously (Cockshull and Horridge, 1978;Kher et al, 1974;Konishi et al, 1985). Our results show that temperature, season, and cultivar affected these effects of ethephon.…”

“…During the production of Summerto-Autumn-flowering chrysanthemums in Japan, growers apply one or two foliar sprays of ethephon after planting, in order to prevent early budding and to achieve sufficient height (Sugiura and Fujita, 2003). However, the effects of ethephon are unstable, and vary with cultivar and with time, season, and method of application (Kher et al, 1974;Cockshull and Horridge, 1978;Konishi et al, 1985). Although the effect of ethephon on the number of leaves is independent of daylength (Cockshull and Horridge, 1978), temperature might affect the responses to ethephon in chrysanthemum.…”

“…For example, it inhibits the elongation of both roots and shoots in peanuts, peas, beans, and cotton (Goeschl and Kays, 1975), delays flowering in Arabidopsis thaliana (Achard et al, 2007), hastens flowering in pineapple (Cooke and Randall, 1968), breaks dormancy in corms and bulbs (Imanishi and Berghoef, 1986;Imanishi and Yue, 1986), and induces bud dormancy in birch (Betula pendula; Ruonala et al, 2006). Because ethylene suppresses flower initiation and internode elongation in chrysanthemum (Tjia et al, 1969), the application of ethephon, which is hydrolysed and releases ethylene in plant tissues (Warner and Leopold, 1969), does so too (Kher et al, 1974;Cockshull and Horridge, 1978). During the production of Summerto-Autumn-flowering chrysanthemums in Japan, growers apply one or two foliar sprays of ethephon after planting, in order to prevent early budding and to achieve sufficient height (Sugiura and Fujita, 2003).…”

Involvement of the ethylene response pathway in dormancy induction in chrysanthemum

“…Exogenous ethylene suppresses flower initiation and internode elongation in chrysanthemum ( Tjia et al , 1969 ), as does 2-chloroethylphosphonic acid (ethephon), which is hydrolysed and releases to ethylene in plant tissues ( Warner and Leopold, 1969 ; Kher et al , 1974 ; Cockshull and Horridge, 1978 ). Ethephon has been shown to induce rosette formation in chrysanthemum ( Sumitomo et al , 2008 ).…”

Ethylene + GA3 Sprays for Delaying Flower Bud Initiation in Chrysanthemum (Dendranthema grandiflora Tzvelv.) Stock Plants

“…A major problem in developing a clonally propagated, 4-to 5-week class of truly DN glasshouse chrysanthemums is the difficulty in producing cuttings on a commercial scale from plants with low LDLN that flower under virtually all glasshouse environments. A synthetic plant growth substance, 2-chloroethylphosponic acid (ethephon) was reported to delay flower initiation in chrysanthemum (Carpenter and Carlson, 1972;Cockshull and Horridge, 1978;Cockshull et al, 1979;Kher et al, 1974). Applying ≥200 ppm ethephon to chrysanthemums with low LDLN under LD delayed or prevented FBI, causing Cockshull et al (1979) to suggest using this technique to delay flower bud formation on stock plants and cuttings.…”