Abstract
Germination and seedling growth of rice (Oryza
sativa) seeds soaked in distilled water and water
extracts of some weeds were investigated in two
laboratory experiments. The root, shoot, leaf, seed
and whole plants of Trianthema portulacastrum L.,
Dactyloctenium aegyptium L. and Eleusine indica
L. were soaked in distilled water (1:20 w/v)
individually for 24 hours at room temperature to
obtain extracts. The germinated rice seeds were
counted and removed from petri dishes every day
in first experiment. Whereas, in second
experiment, rice seeds were sown in sand culture
to assess the seedling growth. Significantly the
maximum mean germination time and time taken
to 50 % germination was observed where rice
seeds were soaked in water extracts of roots of
Trianthema portulacastrum L. The rice seeds
soaked in leaf extracts of T. portulacastrum L.
showed the maximum inhibitory effects on root
and shoot length of rice whereas, root and shoot
dry weight per seedling as a result of interactive
effect of weeds and water extracts was
significantly minimum when rice seeds were
soaked in root extract of Dactyloctenium
aegyptium L. Pre sowing soaking in water extract
of seed of T. portulacastrum increased shoot length
of rice over control. Pre sowing soaking by leaf
extract of T. portulacastrum proved to be the most
injurious to germination and seedling growth of
rice.
Keywords: Allelopathy