Illinois State Florists' Association
IN RECENT YEARS there have been many discuss ions with growers concerning poinsettia fertilization practices and the effects of carbon dioxide (CO.) on the growth of this crop. We have also been asked for information on the causes of leaf drop in relation to soil potassium levels, the effects of CO. on the ultimate height of commonly grown varieties, and the effects of fertilization on bract size and time of flowering. It was there fore decided to conduct several poinsettia trials in order to provide answers to some of these questions. These were largely demonstration-type experiments, with the plants grown as closely to commercial standards as possible. Treatments Used Cuttings of the varieties 'Paul Mikkelsen,' "Mikkelpink,' 'Improved Ecke White,' 'Barbara Ecke Supreme,' and 'Elisabeth Ecke' were taken on Aug. 26 and rooted in sand under intermittent mist. When rooted, the cuttings were placed in 3-inch clay pots and held in these Hfttil root development was satisfactory. On Oct. 6 the plants were panned, three plants to a 6-inch pan. The soil used for potting and panning was a mixture of equal parts of loam, perlite and Canadian peat moss. A 4-inch potful of both superphosphate and gypsum were added to each wheelbarrow load of the mix.
Keywords: Superphosphate ions Treatments Loam, perlite and Canadian peat mo Supplemental C02