Abstract:
Barley is one of the major crops for large numbers of people living in the highlands of Ethiopia.
However, it suffers the greatest yield reduction due to weed competition. Therefore, this study was
conducted in 2019 during the main cropping season at Asagerit woreda, to determine the effect of
plant spacing and weeding frequency on weed infestation, yield component and grain yield of
barley. The experimental treatment consisted of three row spacing (10 cm, 20 cm and 30 cm) and
six weeding frequencies (W1 = one weeding by hand hoeing two weeks after crop emergence, W2=
one weeding by hand-hoeing three weeks after crop emergence, W3= one weeding by hand-hoeing
four weeks after crop emergence, W4= two weeding by hand-hoeing two and four weeks after crop
emergence, W5= weed-free check, and W6 = weedy check). The experiment was laid out in a
randomized complete block design in a factorial arrangement and each plot was replicated three
times per treatment. It was observed that broad leaved weed species were dominant in the study
area with a relative density of 74.6% followed by grasses with relative density of 24.3% whereas
sedge weed species were the least abundant ones with relative density of 1.04%. Interaction of
weeding frequency and spacing significantly affected number of productive tillers per plant, plant
height, number of grains per spike, aboveground biomass yield and grain yield of barley. Days to
heading, spike length, thousand grain weight and harvest index were significantly affected by the
main effects of weeding frequency and plant spacing. Comparing weeding frequency and spacing,
significantly higher yield and yield components of barley were obtained from wider spacing (30
cm) and weed free check and with all weeding frequencies as compared to narrow spacing.
Treatments left weedy check and in10 cm row spacing produced highest dry biomass weight for
both broad and grass weed species. Based on the result, the maximum grain yield value (5263.2
kg ha-1
) was recorded from the weed free check and when sown with 30cm row spacing while the
lowest grain yield (1030.0 kg ha-1
) was recorded from un-weeded barley sown at 30 cm apart).
The economic analysis revealed that the highest net benefit and MRR was obtained in response to
combining 30 cm row spacing with either weed free check or weeding twice at 2 and 4 weeks after
crop emergence. It could be concluded that sowing of barley at 30 cm row spacing and weeding
the crop twice or keeping it completely weed free resulted in optimum growth and grain yield of
the crop.
