Promotion of flowering in stock [Matthiola incana (L.) R-Br.] by prohexadione-calcium in plastic-film greenhouse conditions

Promotive effects of prohexadione- calcium (PCa) on vegetative growth and t he time of anthesis (flowering) of Matthiola incana (L.) R. Er. in plastic- film greenhouse conditions were investigated. Low temperature requirement f or flowering is more stringent for late flowering cultivars than for early flowering cultivars. The flowering season of 'Sourei' (extremely early), 'P earl Pink' (early) and 'Fujimusume' (mid) was significantly accelerated in PCa- 10, PCa- 100 and GA(3)-100 ppm treatments compared to that in the cont rol. Although GA(3) treatment significantly decreased spike length and stem diameter, decrease of Spike length was not observed and that of stem diame ter was not significant in PCa- 10 and 100 ppm treatments. The flowering ti me of 'Banrei' (late) was promoted in PCa- 100 and PCa- 1000 ppm treatments . High dose of PCa treatment decreased length of cut stem. These results in dicate that accelerating flowering rime in summer sown M. incana is possibl e by PCa treatment in the plastic-film greenhouse conditions.