Chemical control of plant habitus in summer-to-autumn flowering chrysanthemum (Dendranthema grandiflora).
Summer-to-autumn flowering chrysanthemums (Dendranthema grandiflora Tzvelev. cv.) are grown outdoors in containers and are characterised by a uniform ball-shaped growth habit. Development of new cultivars expanded the production of marketable plants from end of July until end of October. During the first weeks of the production cycle plants were pinched regular to increase branching but also to prevent development of precocious initiated flowers. This pinching treatment however increases Labour costs and is therefore more and more abandoned. The effectiveness of ethephon for terminal bud destruction was evaluated for three cultivars 'Draga', 'Tardero' and 'Veria Dark'. PLants were sprayed with 0-240-480-1200-2400 mg a.i./l. Ethephon spraying resulted in growth arrest and apical bud necrosis and higher doses resulted in more pronounced reactions. The highest dose (2400 mg a.i./l) resulted in phytotoxicity one week after application; phytotoxicity was more severe in 'Veria Dark' than 'Draga' and 'Tardero'. Ethephon treatments significantly delayed flowering and have potential to be used in commercial production schemes of summer-to-autumn flowering chrysanthemum in outdoor conditions.
Blindeman
Liesbet
L
Research Centre for Ornamental Plants, PCS, Belgium.
Van Labeke
Marie-Christine
MC
D031202:Chrysanthemum / Q000145:classification / Q000254:growth & development / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D035263:Flowering Tops / Q000187:drug effects* / Q000254:growth & development; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D010937:Plant Growth Regulators / Q000494:pharmacology*; D012621:Seasons; D013045:Species Specificity
D009943:Organophosphorus Compounds; D010937:Plant Growth Regulators; C005073:ethephon