Abstract

Recent trends in soil microbiology suggest that certain soil microbes have a positive effect on seedling growth and development. A study was conducted to investigate the interactive effect of the plant-growth promoting fungi Trichoderma harzianum and the arbuscular mycorrhizal fungi (AMF) in growth and development of tomato (Solanun lycopersicum) seedlings grown under greenhouse conditions. A 3 × 3 factorial experiment was laid out in a completely randomised design with six replications. At harvest (42 DAP), when compared with the control, T. harzianum and/or AMF treated plants improved shoot length, root length, dry shoot mass and dry root mass. Pre-inoculation with AMF increased shoot N, P and S content of tomato seedlings, whereas pre-sowing with T. harzianum alone increased the shoot N. Generally, shoot Zn and Mn content were affected by both fungi, with the best result observed when AMF was applied 2 weeks after T. harzianum. The percentage of roots colonised by AMF was less than 15% regardless of the time when T. harzianum was applied. However, the percentage of roots colonised by T. harzianum was greater than 90% at all times. In conclusion, this study suggested that T. harzianum and AMF have the potential to improve tomato seedling growth and development.

Key words: Essential mineral nutrients, mycorrhiza, plant-growth promoting fungi, seedling quality, Solanum lycopersicum.