GROWING MEDIA FOR ORGANIC TOMATO PLANTLET PRODUCTION

Summary in the original language of the document

The choice of growing media and the strategy of application of organic fertilizers is considered one of the largest challenges for production of organic tomato plantlets for transplanting. We have measured the growth and the ability of young tomato plantlets to extract plant nutrients from an organic growing media. Plants were grown in 0.45L pots. Plant nutrition were either entirely based on the mineral nutrients, available from the organic growing media or based on a combination of nutrients from the organic growing media and fertigation with water-soluble organic fertilizers during plantlet production. The first results shows that plant dry weigth and uptake of nitrogen, phosphorus and potassium was reduced in the organic growing media compared to the control, peat based growing media, but the results also indicate a possibility for optimizing the suggested organic growing media in order to increase the nutrient acquisition and utilization efficiency of the plants. Improved organic growing media can supply most of the necessary plant nutrients needed for the plant, limit the need for supplementary fertilisation, and be an alternative to conventional production with inorganic fertilizers.