In order to reveal the effect of Trichoderma isolates on maize
seedling growth directly, two inoculate applications were evaluated.
In one set experiment, inoculums were presented after planting via
spore presentation and in another set, the seeds were potted in
inoculated soil. In the first experiment, three maize surface
disinfected seeds (soaked in 0.5% hypochlorite sodium (NaClO) for
5 min then rinsed and washed thoroughly in sterile distilled water 3
times) were sown in each pot. Two weeks after potting, when the
seedling was in two leaves stage, 10 ml spore suspension (prepared
as mentioned above) was added on the surface of the soil near the
emerged seedling. In the control pots, seed was watered with noninoculated
medium distilled water. One month after inoculating,
plant response parameter such as total chlorophyll content and
stomata conductivity were measured in each plant via chlorophyll
meter (Model; SPAD 502 Konika Minolta Sensing Inc, Japan) and
stomata conductivity (Model; SC-1 Eijkelkamp, Netherland)
instruments respectively, as well as plant height, root height, aerial
weight, root weight and total leaf area (Model: Li 3100, Area meter
Licor Lincon Nebraska, USA), after uprooting the plants and
washing them under running tap water to remove residual soil from
the roots. In the second experimental set, Trichoderma inoculums
were prepared by inoculation of sterilized wheat grains in 1 L
conical flask (autoclaved at 121°C for 20 min twice with 24 h
distance) by 5 mm Trichoderma isolate mycelia plug, before
incubating at 25±1°C in a growth chamber for 14 days and then
were mixed with soil in 1:10 w/w rate before seed potting. In the