EVALUATION OF SOWING DATE, NITROGEN LEVEL, VARIETY AND HERBICIDE FOR THE CONTROL OF Striga heraionthica (DEL.) BENTH IN SORGHUM (Sorghum blcplor (L) KOENCH)
EVALUATION OF SOWING DATE, NITROGEN LEVEL, VARIETY AND HERBICIDE FOR THE CONTROL OF Striga heraionthica (DEL.) BENTH IN SORGHUM (Sorghum blcplor (L) KOENCH)
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Date
1990-02
Authors
ADEOSUN, JAMES OLASUNKANMI
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Abstract
A greenhouse study was conducted at the Institute for Agricultural
Research, Ahmadu Bello University, Samaru, Zaria (11o11' N 07°E) in
the Northern Guinea Savanna Ecological Zone and two field trials
during the 1988 wet season on the commercial farm of Ahmadu Bello
University, Mokwa (09°18'N 05' 04°E) in the Southern Guinea Savanna
Ecological Zone to evaluate dates of sowing, nitrogen levels, crop
varieties and herbicides for the control of Striga hermonthica in
sorghum.
Early sowing of sorghum on 23 June, 1988 resulted in more
vigorous crop growth and grain yield increase of 64.2% over the late
sowing of 14th July. The effect of nitrogen was significant on leaf
area per plant at
3 weeks after sowing (WAS) and on grain yield.
The effect of variety was significant on leaf area at 8 WAS, Striga
score, percentage of Striga - infested sorghum plants, Striga count,
head weight, grain yield and the weight of 1000 seeds. Increasing
nitrogen from 60kg N/ha to 90kg N/ha increased the grain yield by
21.7%. The most promising variety which supported low number of
emerged Striga shoot and produced the highest grain yield was S.35
with 76.5% grain increase over the more susceptible variety L.187,
which also had 57.9% lower striga count than variety L.187.
Variety ICSV 1007 consitently exhibited the highest level of resistance
to Striga hermonthica both in the greenhouse and under field
condition as reflected in the number of emerged Striga shoot but its
yield was low. Significant interactions between sowing date x
nitrogen, nitrogen x variety, sowing date x variety and second order
interaction between sowing date x nitrogen x variety on various
parameters studied were also observed. Grain yield was negatively
iv
correlated with Striga count (r = - 0.28*).
Among the herbicide treatments evaluated, atrazine plus
terbuthylazine at 1,25 + 1.25 kg a. kg a.i/ha and diflufenican plus
atrazine at 0.40 + 1.00 kg a. i/ha applied pre-emergence alone,
respectively increased grain yield by 76.7% and 74.1% over the
unweeded control, and 32.8% and 25.3% over two hoe-weedings.
Supplementary hoe-weeding apparently encouraged Striga emergence.
Grain yield was also correlated with the Striga count (r=s -26*)
and percentage of Striga infested sorghum plants (r=-0.32*).
Description
A THESIS SUBMITTED TO THE POSTGRADUATE SCHOOL, AHMADU BELLO
UNIVERSITY, 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.
FEBRUARY, 1990
Keywords
EVALUATION,, SOWING DATE,, NITROGEN LEVEL,, VARIETY AND HERBICIDE,, Striga heraionthica (DEL.),, (Sorghum blcplor (L) KOENCH)