Effects of nitrogen fertilizer, sugarcane trash mulch, cowpea intercrop and herbicides on itchgrass control, yield and quality of sugarcane
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Date
1994
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Sokoine University of Agriculture
Abstract
A field experiment was conducted (under rainfed
conditions with supplimentary irrigation) to evaluate the
effects of nitrogen fertilizer, post emergence herbicides
and other weed control treatments on itchgrass ( Rottboellia
cochinchinensis (Lour) Clayton) control, yield and quality
of sugarcane ( Saccharum officinarum L.).
The
experiment
was
laid
out
as
split-plot
randomized complete block design replicated
in
a
four times.
Nitrogen fertilizer rates (0, 50 and 100 kg N/ha) were main
plots while herbicides and other weed control treatments
were subplots.
The herbicides included gramuron
(3.2 kg
a.i/ha), basta (2.0 kg a.i/ha) and asulam (3.7 kg a.i/ha).
Other weed control treatments were cane trash mulch, cane
trash mulch plus hand weeding,
intercrop plus hand weeding,
cowpea intercrop,
gesapax combi
cowpea
(4 kg a.i/ha)
plus two hand weedings plus mechanical cultivation,
weed
free and unweeded checks.
Nitrogen fertilization was ineffective in controlling
itchgrss. Mulching or intercropping supplemented with hand
weeding as well as gesapax combi (4 kg a.i/ha) plus two
hand
weedings
plus
mechanical
cultivation
completely
eliminated itchgrass. Asulam (3.7 kg a.i/ha) controlled the
weed by an average of 88%. Gramuron (3.2 kg a.i/ha) basta(2.0 kg a.i/ha) and mulching had between 70 and 75% control
of the weed.
Intercropping was
ineffective
in itchgrass
control.
Increasing the rate of nitrogen from 0 to 100 kg N/ha
significantly (P<0.05) increased cane yield by 14%. Plots
which were
mulched
and
then
weeded,
hand
treated
with
asulam (3.7 kg a.i/ha) or gesapax combi (4 kg a.i/ha) plus
two
hand weedings
better
control
plus
of
mechanical
itchgrass
cultivation provided
higher
and
cane
yields
averaging between 85 and 88 tons/ha.
Sugarcane yields positively correlated with number of
sugarcane tillers (r=0.766), stalk population (r=0.734) and
stalk length (r=0.433). Among sugarcane growth parameters,
tiller
length
counts,
of
number
negatively
harvestable
correlated
stalks
(r=0.749,
and
0.850,
stalk
0.886
respectively) with itchgrass count. Analysis of coefficient
9
of determination (r )
influenced (r^=0.60)
indicated that cane yield was more
by tiller counts
than by the other
parameters.
Application of
100
kg
N/ha
reduced sucrose content which
is
significantly
(P<0.05)
the main parameter
sugarcane quality compared to unfertilized cane.
ofiv
Economic
analysis
showed
that
mulching
plus
hand
weeding applied with 100 kg N/ha had the highest marginal
rate of return of 192%.
Description
Dissertation
Keywords
Nitrogen fertilizer, Quality of sugarcane Cowpea intercrop, Itchgrass control, Saccharum officinarum L., Sugarcane trash