ISHS Acta Horticulturae 82: Symposium on Production of Protected Crops in Peat and other Media
EFFECT OF MINERAL AND SLOW-RELEASE NITROGEN COMBINATIONS ON THE GROWTH OF TOMATO IN A CONIFEROUS BARK MEDIUM |
| Authors: | A.R. Barragry, J.V. Morgan |
| Abstract:
The effects of mineral and slow-release N on the growth of tomato in a bark medium of mixed conifer composition was assessed. Four mineral N sources, (NH4)2SO4, CaNH4NO3, Ca(NO3)2 and CO(NH2)2 were applied at 206, 412 and 824 mg N/l. Each of these was combined with ureaformaldehyde to provide an additional 275, 550 and 825 mg N/1. CaNH4NO3 was also combined with Osmocote (18–6–12). Excluding (NH4)2SO4, the optimal rates of N amendment were 206 mg of mineral N combined with 550 or 825 mg of ureaform. Increases in plant dry weight up to 33% were recorded for bark over the peat control 19 days after potting. Dry weights decreased with the addition of 412 and 824 mg mineral N. Plant growth in the Osmocote treatments was restricted by P deficiency. Twenty six days from planting none of the bark treatments were superior to the control as measured by plant dry weight. This was due to delayed feeding coupled with N immobilisation in bark. Flower number in the first inflorescence was generally lower in bark, but the onset of anthesis was largely unaltered. The results indicate that the inclusion of mineral and slow-release N can successfully cater for plant requirements and the N immobilisation requirements in uncomposted bark media. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
