Use of different growing media and nutrition in organic seedling production

Legislation in organic agriculture also sets up the rules for production of seeds and other plant propagation materials. In Turkey, organic seedlings are raised mostly by the farmers themselves since propagation material released from commercial nurseries is very limited due to the lack of standard protocols and research under controlled organic conditions. The aim of this research was to develop growing medium as an alternative due to the pressures on peat as a non-renewable resource and fertilization programs using local resources that could be applicable at commercial level to produce organic tomato ('Meils') seedlings. In two experiments, liquid vermicompost, diluted poultry manure and liquid composted farmyard manure were tested in order to develop the nutritional program with (1) peat, (2) local peat + clinoptilolite + vermicompost (1:1:1; v:v), (3) local peat + perlite + vermicompost (1:1:1; v:v) and (4) local peat (60%) + vermicompost (40%). In the first experiment, only the effect of growing media on shoot dry weight was found significantly different while in the second one the main and interaction effects of treatments were significant. The mixture of local peat and vermicompost was as good as peat in terms of shoot fresh and dry weights. Among the tested fertilizers, liquid composted farmyard and poultry manure were found promising however liquid composted farmyard manure could be more appropriate for commercial use considering its effects on plant fresh weight, availability and cost.