Impact of Trichoderma harzianum on the early growth of Amaranthus spinosus under normal gravity and microgravity conditions

Abstract

This study investigated the use of Trichoderma harzianum as bio-fertilizer for the early growth of Amaranthus
spinosus (spinach) on land and space environment using a simulated microgravity device. White and black
spinach seeds were placed in different Petri dishes. The seeds were treated with Trichoderma harzianum for at
least 24 hours to allow proper absorption by the seeds. The treated seeds were subjected to different growth
environments (normal gravity and clinorotated). The treated seeds of spinach were sown inside Petri dishes each
containing 10 ml of 1.5% DuchefaBiochemie plant Agar-Agar. The experimental design for each spinach variety
was completely randomized design having two treatments (i.e. normal gravity and clinorotated) with three
replicates each. This gave rise to a total of six Petri dishes per variety. The clinostat was rotated at a speed of 20
rpm for 72 hours (3 days) and observed. The result shows that the two varieties of spinach responded better in
terms of the percentage germination, radicle length, and plumule length under the normal gravity than
microgravity environment. However, the seeds of the microgravity germinated earlier than those of the normal
gravity. The treatment with Trichoderma did not produce any significant effect on the germination and growth of
the spinach varieties under both environments. The influence of the biofertilizer could have been more positively
seen at the later stage of the growth of the plant.