Abstract:
The present study was conducted to investigate the phytotoxic effects of aqueous
methanol extract on leaf and bark of Eucalyptus camaldulensis on germination
and seedling growth of some selected monocot (foxtail millet and barnyard grass)
and dicot (cauliflower, broccoli and tomato) plant species from June 2016 to June
2017. The aqueous methanol extract obtained from leaf and bark of eucalyptus
followed six different concentrations ( T
0
= 0 g mL
-1
, T
1
=0.001 g mL
=0.003 g
mL
-1
, T
3
=0.01 g mL
-1
, T
4
=0.3 g mL
-1
, T
5
=0.1 g mL
-1
) were tested on five test
species under laboratory condition. The aqueous extract obtained from leaf of
eucalyptus were tested on five test species under net house at six different
concentrations (T
0
= 0 ppm, T
1
=1 ppm, T
2
=2 ppm, T
3
=3 ppm, T
=5
ppm ). Rsults revealed that a pronounced inhibitory effect of the aqueous and
aqueous methanol leaf and bark extract of eucalyptus was observed on seed
germination and seedling growth of five test plant species. The germination
efficiency, plumule and radicle length and dry weight of plants were completely
inhibited at the highest concentration of aqueous extracts (0.1g mL
) whereas
least inhibition was observed at control at both laboratory and field condition.
Maximum treatment effect was observed in germination and seedling growth of
monocot plants (foxtail millet and barnyard grass) followed by three dicot plants
(cauliflower, broccoli and tomato). Since foxtail millet and barnyard grass was
mostly affected by different treatment effect, thus phytotoxic effect of eucalyptus
may reduce weed competition with crops by affecting the germination and
seedling growth of foxtail millet and barnyard grass. Therefore, it is possible to
use these extracts as a component for production of bio-herbicides due to their
phytotoxic effects on weeds and crops and considered as a natural way for
sustainable weed management.
