Arbuscular mycorrhiza has limited effects on yield and quality of tomatoes grown under soilless cultivation

Abstract

A study was conducted investigating the possible utilization of mycorrhiza to enhance yield and quality of tomatoes grown in a soilless culture system using sawdust or coir as growing media. The experiment was carried out in temperature-controlled and non-temperature-controlled (NTC) tunnels. Fertigation was applied at three levels (100%, 75%, and 50%) of the recommended nutrient concentration. Mycoroot™, containing four arbuscular mycorrhizal species (Glomus etunicatum, Paraglomus occultum, Glomus clarum, and Glomus mosseae), was applied at seeding, as well as transplanting. Growing tomatoes under reduced nutrient supply reduced the total soluble solids in the juice of the fruits, but improved total and marketable yield, as well as the number of marketable fruits. This effect was more substantial in the temperature-controlled tunnel than in the NTC tunnel. Fruit firmness and leaf chlorophyll concentrations were significantly higher in plants grown in the temperature-controlled tunnel. Growing tomatoes in sawdust improved the leaf Mn and Ca concentration over that of tomato plants grown in coir. Mycorrhiza colonization did not have a beneficial effect on tomato yield and quality. Further studies, including different media, nutrient composition, and concentration need to be carried out to investigate the possible effect of AMF failing to improve yield, despite AMF root colonization, and to reveal the cause of the poor beneficial effect of AMF on tomato plants grown under soilless culture. © 2013 Copyright Taylor and Francis Group, LLC.