ISHS Acta Horticulturae 82: Symposium on Production of Protected Crops in Peat and other Media
A COMPARISON OF THE EARLY GROWTH AND NITROGEN UPTAKE OF TOMATOES IN PEAT AND BARK BASED COMPOSTS |
| Authors: | K. Chilton, A. Concannon, V. Devonald |
| Abstract:
The experiment compared the early growth of pot-grown tomatoes in 3/1 peat/coarse sand with base fertilizer and 3/1 bark/coarse sand with base fertilizer, at two levels of liquid feeding. In the bark-based composts, visually assessed vigour of growth, shoot height, shoot fresh weight and shoot dry weight were significantly depressed. The higher level of liquid feeding significantly increased shoot fresh weight and dry weight but did not compensate for the depressive effect of the bark compost. Chlorosis appeared in the bark-grown plants from eleven days after pricking out. Analysis of the composts for total and nitrate nitrogen at the beginning and end of the experiment suggested that any available nitrogen came from the fertilizer applications, and that there were no residues of available nitrogen in the composts at the end of the experiment. In the case of the peat-based composts, the total nitrogen of the shoot system, derived from micro-Kjeldahl analysis of the fourth leaf from the base, was similar to the total nitrogen applied to the pot during the experiment, but in the case of the bark-based composts, it was lower. This was interpreted as evidence of the diversion of available nitrogen by decay micro-organisms. This conclusion was supported by the fact that the bark-based composts showed a significant increase in total nitrogen over the course of the experiment while the peat-based ones did not. | |
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