GROWTH AND NUTRITIONAL STATUS OF BEDDING PLANTS ON COMPOST-BASED GROWING MEDIA
The agronomic performance of and the mineral composition and trace element content in Callistephus, Impatiens, Lobelia and Petunia were tested by growing the plants on substrates of white peat and 50 or 100% green waste and sewage sludge (80% + 20% v/v) compost (CP); a commercial peat medium (CM) of black and white peat (2:1 by vol.) was used as control. At flowering, the agronomic parameters were compared by ANOVA and plant nutritional status was checked by vector analysis. Substrate-species interactions (P<0.001) were evident for all measured parameters. Callistephus and Petunia were the most adaptable, increasing growth and flower production even at 50% CP. While Impatiens reacted negatively only to unblended CP, Lobelia showed a negative trend for all parameters even at 50% CP. Significant too was the common tendency of plants to accumulate micronutrients and heavy metals. Callistephus for Ni, Petunia for Al and Fe, and Impatiens for Ni, Al, Fe, Na and Al more than doubled the control uptake rate on 50% CP. Moreover, Callistephus showed a good aptitude for controlling Na, Mn, Pb and Cd translocation, as Lobelia did for Cd. The low ability of Impatiens on 100% CP to exclude Pb is remarkable, too. Lobelia proved to be the most susceptible species to the compost use, and high level of the metal ions, as well as being unable to fully exclude Al and Ni.
Grigatti, M., Ciavatta, C. and Giorgioni, M.E. (2008). GROWTH AND NUTRITIONAL STATUS OF BEDDING PLANTS ON COMPOST-BASED GROWING MEDIA. Acta Hortic. 779, 607-614
substrates, nutrients, tissue composition, Callistephus chinensis, Impatiens walleriana, Lobelia erinus, Petunia × hybr