Evaluation of different growth media for tomato seedlings to optimize production and water use

ABSTRACT- Soilless cultivation systems are used to attain higher performance, improve crop quality, conserve water and land, and protect the environment better. This study has attempted to use some agricultural wastes and organic matter, and management practices to optimize water holding capacity of cultural media, which are suitable for the growth of tomato seedlings (Solanum lycopersicum.). Fifteen different substrate (growth media) mixtures with a mineral fraction (sand and perlite) and organic fractions (bagasse, oak tree bark, poplar wood chips) were prepared and compared. Sand (۲-۴mm) and perlite (۴-۶ mm) were mixed at ۰, ۱۰, ۲۰, ۳۰ and ۴۰ percent volume ratios with organic fractions at ۰, ۳۰ and ۶۰ percent. The experiment was arranged in a completely randomized design with ۱۵ treatments and ۳ replications with ۶ observations per treatment. During the seedling growth period (۴۵ days), every ۷ days, ۹۰ seedlings were harvested (data for three periods were used) to determine the effect of the growth media on different growth parameters(plant dry matter and leaf area) and indices (RGR, NAR, and SER). The growth rate of tomato seedlings generally increased over time the rate of which varied with treatments. Seedling height, stem diameter, plant fresh weight and dry matter indicated that the highest length (۲۵.۹۱ cm) and diameter (۴.۸۳ cm) of the tomato seedlings was in treatment eight (S۳۰P۱۰T۳۰B۰C۳۰). It was also shown that the sand fraction as a mineral component had a better performance compared to perliter in growth parameters. For the organic component of the growth media, tree bark treatments were better than wood chips or bagasse. The bagasse treatment had the lowest fresh weight and dry weight of shoot and root. The treatments with water holding capacity of ۹۰-۱۰۰% showed the best response in the growth of tomato seedlings.