Possible Use Of Ethylene To Enhance Germination

     Recently I went to a garden store to purchase more perlite and found that they are now selling a Bonide product called "Fruit Eliminator" "Florel brand G/R Plant Growth Regulator".The active ingredient is 3.90 % Ethephon.  I purchased an 8 Fl. Oz bottle for $9.99.  In the older Rose Hybridizers Newsletters there have been articles about using Ethephon (which releases ethylene) to ripen hips, but the only reference to germination  enhancement that I found was in an article by Ron. J. Bell from Harkaway, Victoria, Australia where he states: "Treating with ethylene gas improves germination, and this can be accomplished by enclosing seed in a container with rotting fruit such as bananas or apples or their skins".  No data were presented.

     The following two paragraphs are from the book "Seeds", by Carol C. Baskin and Jerry M. Baskin, pages 72-73, Academic Press, 1998.
     "Ethylene treatments at normal atmospheric concentrations of carbon dioxide 0.0355% by volume) stimulate seeds of a number of species to germinate (Egley and Dale, 1970, Olatoye and Hall, 1973; Egley, 1978, 1980; Taylorson 1979; Jones and Hall, 1979; Keegan et al., 1989), but the effects of ethylene frequently are enhanced when the carbon dioxide concentration is raised above 0.0355% (Negm ct al., 1973; Katoh and Esashi, 1975b; Esashi and Katoh, 1975, Esashi et al., 1976). However, ethylene in combination with 10 % carbon dioxide inhibited the germination of Siriga lutea seeds (Egley and Duke, 1985). The dormancy-breaking action of ethylene on Chenopodium album seeds increased with an increase in the nitrate level in the seeds (Saini et al., 1986; Saini and Spencer, 1987).

     Ethylene causes changes in dormancy states primarily by breaking dormancy.  However, not all seeds respond to ethylene, and sorne are inhibited by it (Olatoye and Hall, 1973; Taylorson, 1979; Suzuki and Taylorson, 1981 ). Seeds that respond to ethylene also germinate to higher percentages in light than in darkness, but ethylene does not promote germination in all light stimulated seeds (Taylorson, 1979). Ethylene can break dormancy (Schonbeck and Egley, 1980a) or substitute for a light requirement for germination (Schonhcck and Egley, 1980a,b). Also, ethylene can break secondary dormancy induced by darkness and/or high temperatures (Schonbeck and Egley, 1981 b; Corbincau et al., 1988). In some species, ethylene-treated seeds germinated at higher temperatures (Schonbeck and EgIcy, 1980a) and under greater water stresses (Schonbeck and Foley. 1980b, 1981 a; Esashi et al., 1989) than nontreated ones. Ethylene increased the osmotic potential in cells of Xalithium penslvanicum embryos (Esashi and Ishizawa, 1989), thereby increasing their growth potential. In seed-priming studies on this species, promotive effects of ethylene increased with water stress and with increased oxygen and decreased carbon dioxide levels (Esashi et aL, 1990)."

     The above indicates that the use of ethylene for rose seed germination enhancement may prove beneficial.   I am using it but I have not run any "control" tests so far.