EFFECT OF NITROGEN AND PERIOD OF WEED INTERFERENCE ON MAIZE/RICE MIXTURE
EFFECT OF NITROGEN AND PERIOD OF WEED INTERFERENCE ON MAIZE/RICE MIXTURE
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Date
1997-11
Authors
USMAN, ALIYU
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Abstract
A field experiment was conducted during 1994 and 1995 wet
season on the research farm of the Institute for Agricultural
Research, Samaru (11'11' N , 07°E 680m) located in northern Guinea
savanna agro-ecological zone of Nigeria. The main objective
was to investigate the effect of nitrogen level and period of
weed interference on maize/rice mixture. The treatments
consisted of three levels of nitrogen (0, 60 and 120kg/ha) and
ten period of weed interference (weed free for 3,6,9, 12WAS
and harvest and weed infested for the same period) . The
treatment were laid out in a split plot design with nitrogen
in the main plot and period of weed interference in the sub
plots.
The result of this study revealed that increasing
nitrogen from 0 to 120kg\ha significantly increased grain
yield of maize up to the maximum of 2243 kg/ha and 3809 kg/ha
in 1995 and 1995 respectively in treatments that were kept
weed-free until 6,9,12WAS and harvest and those initially
weed-infested for the first 3WAS. On the other hand, nitrogen
application did not increase the grain yields of maize on the
plots weed-infested until harvest and those kept weed-free
initially for 3WAS. For rice, increasing nitrogen from 0 to
120kg/ha significantly increased grain yield up to the maximum
of 933 and 1216 kg/ha in 1994 and 1995 respectively in
treatments that were kept weed-free until 6,9,12 WAS and
harvest. Nitrogen application did not increase the grain
yield of rice on the plots that were kept weed-free initially
for 3WAS in both years and those weed-infested for 9WAS and
more in 1995.
As compared with the crops kept weed-free throughout the
lifecycle, uncontrolled weed growth resulted in 83.03% and
93.85% reduction in average grain yield for both years in
maize and rice respectively. The critical period of weed
interference in maize and rice mixture was established to be
between 6 and 9WAS for maize and 5 and 9WAS for rice.
There was negative correlation between the maize grain
yield and cumulative weed dry matter production (r=-0.028, r=
-0.20 in 1994 and 1995 respectively) as well as weed cover
scores (r= -0.33, r= -0.21 in 1994 and 1995 respectively).
Rice grain yield was also negatively correlated with
cumulative weed dry matter production (r= -0.20, r= -0.52 in
1994 and 1995 respectively) as well as weed cover scores (r= -
0.21, r = -0.46 in 1994 and 1995 respectively). Other plant
characters for maize and rice were highly positively
correlated with the grain yield.
Description
A Thesis submitted to Ahmadu Bello University Postgraduate
school, in partial fulfillment of the requirements for the
degree of Master of Science in Agronomy.
DEPARTMENT OF AGRONOMY
FACULTY OF AGRICULTURE
AHMADU BELLO UNIVERSITY,
ZARIA - NIGERIA
Keywords
EFFECT,, NITROGEN,, PERIOD,, WEED,, INTERFERENCE,, MAIZE/RICE,, MIXTURE