Abstract:
The experiment was conducted at the experimental field of Sher-e-Bangla Agricultural
University, Dhaka, Bangladesh during the period from October 2007 to February 2008
to study the al]elopathic effect of
Brassica
biomass to control weeds and yield of
wheat. The experiment consisted of two factors of which Factor A: 3 kinds of
Brass/ca
species viz. Si:
Brass/ca campesiris. S
2: Brass/ca juncea
and S
3
: Brc:ssica
napus
and Factor B: incorporation methods of
Brass/ca
biornass (5 levels) like: B
0:
Control (no bioniass application); B
1
: Spreading above the ground; B
2
: Mixed with
soil; B3
: Spreading in line and B
4:
50%
spreading + 50% mixed with soil. At 30 days
after sowing (DAS), the maximum numbers of weeds
(25.53
n12
) were found in the
plot treated with Brass/ca funcea
which was 44. 81°/a higher than
Brass/ca campesiris.
At 50 DAS. Bras's/ca juncea
also showed the highest weed population (20.20 m
2).
However, Brass/ca campes Iris
resulted with the best effect on weed control showing
the least number of weed population (14.07 rn
2
). At 30 DAS, the lowest weed
population (15.33 m 2
) was seen by 133
while the highest (26,89 m
2
) was found in the
B2
. At 50 DAS, the highest (20.89
1112)
weed population was found by B
2
whereas. B4
showed the lowest (13.11 m) population. S
1 B2
showed the lowest density of weeds
(8.67n12
) at 50 DAS which was significantly lower than S
2B0 (37.33n12
) and S3B2
(40.00m 2
) at 30 and 50 DAS respectively. Among the
Brass/ca
species, S
2 produced
the highest grain yield (3.52 t ha
d
) while the lowest (3.32 t ha
d
) was obtained from S.
The highest grain yield
(3.54
t ha
d
) was recorded from B
0
while the lowest (3.32 t ha
')was recorded from B2
. The S2 B1
had the highest grain yield (3.83 t ha") whereas the
lowest (3.06 t ha") was recorded from S
3B1
. It is appeared from the above results that
Brass/ca canzpeslris
and B4
incorporation method was mostly effective in controlling
weed. But yield was not affected by both species and incorporation methods
