Relationship between Applied Fertilizer and Accumulated Levels of Nitrogen and Sulfur in a Soilless Mix
| Autor: | Walter W. Stroup, M. Elizabeth Conley, Ellen T. Paparozzi |
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| Rok vydání: | 1996 |
| Předmět: | |
| Zdroj: | HortScience. 31:584a-584 |
| ISSN: | 2327-9834 0018-5345 |
| DOI: | 10.21273/hortsci.31.4.584a |
| Popis: | Three cultivars of poinsettia, Freedom Red, Lilo and Red Sails, were grown in a peat:perlite:vermiculite mix according to a commercial production schedule. Twelve selected nitrogen–sulfur fertilizer combinations were applied (125, 150, 175 ppm N with either 12.5, 25, or 37.5 ppm S, 225 and 275 ppm N with either 37.5 or 75 ppm S). The experimental design was a split plot with cultivars as the whole plot and fertilizer levels as the split-plot factor. Mix samples were taken initially, at production week 7 and at the end of the experiment. Nitrate-nitrogen, sulfate-sulfur and total nitrogen were determined. Data were analyzed using SAS PROC MIXED. Visually all cultivars responded similarly to all treatments and were salable. Thus, levels of N as low as 125 or 150 with 12.5 ppm S produced quality plants. Sulfate-S tended to accumulate in the mix while nitrate-N and total N did not. Both nitrate-N and sulfate-S concentrations were affected by an interaction between the cultivar and the amount of S applied with `Freedom' better able to utilize available sulfur. `Lilo' removed more nitrate-N and total N from the mix than `Freedom' which removed more than `Red Sails', but only at specific levels of sulfur. There was no cultivar by nitrogen interaction for any variable measured. |
| Databáze: | OpenAIRE |
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