Abstract:
Faba bean (Ficia faba L.) is among the leading legumes in area coverage and production in
Ethiopia. However, its productivity is low mainly due to in appropriate plant population and
weed management. Studies on the combined use of inter row spacing and weed management
for faba bean are lacking at Omo nada area. Therefore, a field experiment was conducted to
determine the effect of inter rows spacing and weed management on yield and yield
components of faba beanin 2018 main cropping season in Jimma Zone, Omo Nada district,
south western Ethiopia. Four inter row spacings ; 30 cm x 10 cm( 333,333 plants ha-1
),40cmx10cm (250,000 plants ha- 1), 50cm x 10cm (200,000 plantsha-1 ) and 60 cm x 10cm
(166,667 plants ha-1) and five weeding regime ; no weeding, one time hand weeding at 20
days after emergence(DAE),two times hand weeding at 20 and 40DAE, three times hand
weeding at 20,40 and 60DAE and application of Dual Gold pre-emergence herbicide at a
rate of 1.00kgha-1supplemented by hand weeding at 40DAE were laid out in a randomized
complete block design with factorial arrangement in three replications. Dataon weed density
and dry weight, crop growth, yield and yield components of faba bean variety Tumsa were
subjected to ANOVA using SAS version 9.3software. The results revealed that interaction
effect of inter rows spacing and weed management significantly (P<0.05) affected weed
density and dry matter, leaf area, leaf area index, plant height, number of pods per plant
,number of seeds per pod, thousand seed weight, grain yield and above ground biomass of
faba bean. However, days to 50% flowering, days to 90% maturity,height to first pod
,Number of productive tillers per plant were not affected by interaction effect of inter rows
spacing and weed management . The highest grain yield (3911.7 kg ha-1) and above ground
biomass (10589.7 kg ha-1) was obtained from widest inter rows spacing (60cm) and twice
hand weeding at20 and 40DAE. Whereas, the lowest grain yield (1984 kg ha-1)was recorded
for narrowest inter row spacing(30cm) or 166667plants ha-1and unwedded plot and the
lowest above ground biomass (5874.6 kg ha-1) was obtained fromcombined application of
50cm inter row spacing or 200000plants ha-1 with unwedded. Grain yield was strongly and
positivelycorrelated with plant height, leaf area, crop biomass, Number of productive tillers
per plant, number of pod per plant, number of seeds per plant and harvest index,however it
was strongly and negatively correlated with weed density and weed dry weight. Partial
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budget analysis revealed that combined application of 60cm inter row spacing or
166,667plants ha-1 with twice hand weeding at 20 and 40DAE resulted in maximum net
return (66,817ETBha-1) with marginal rate of return of 3125%.Thus, 60cm inter row spacing
or plant density of 166,667 plants ha-1and twice hand weedingwas found to be better both
agronomically andeconomically for faba bean variety Tumsa production under rain-fed
conditions in the experimental area.
