Abstract

In recent years, a wide range of soilless culture techniques have been developed and commercially introduced for intensive production of horticultural crops, particularly in greenhouses. Reasons for replacing soils as growing media arise from plant protection problems with soil-borne pathogens and environmental regulations against groundwater pollution with nitrate and pesticides. The aim of this study was to compare some growing indexes of greenhouse tomato that were cultivated in some substrates, such as perlite, date-palm peat and coco peat. The research was conducted in a completely randomized design with 6 replications. The treatments were coco peat + perlite (v/v=50%)‚ date-palm peat + perlite (v/v=50%)‚ perlite (100%) and date-palm peat (100%). Papadopolus formula was used for nutrient solution during plant growth with fertigation method. Also temperature, humidity and irrigation rate was constant for all treatments. Comparison of means showed that the media had no significant effect on concentration of nutrient elements in fruit such as N, P, K and yield in all treatments. Minimum and maximum amount of fruits yield was in date-palm peat and perlite treatments respectively. That had no significant difference with other treatments. Higher amount of total soluble solids (TSS) related to coco peat + perlite treatment that has not any significant difference with date-palm peat + perlite, perlite and date-palm peat treatments. Also, culture substrates had no significant difference on the amount of ascorbic acid. The results showed that date-palm peat is an appropriate media for soilless culture with suitable physical and chemical properties, availability and low cost. Therefore, it can be a new substrate that is introduced for replacing other media.

Key word: Soilless, substrate, date-palm peat, total soluble solids, ascorbic acid.