Competition Effects of Purple Nutsedge (Cyperus Rotundus L.) on Growthand Yield of Tef[Eragrostis Tef (Zucc.) Trotter] in Ethiopia

Competition Effects of Purple Nutsedge (Cyperus Rotundus L.) on Growthand Yield of Tef[Eragrostis Tef (Zucc.) Trotter] in Ethiopia

Tef [Eragrostis tef (Zucc.) Trotter] is the staple food of Ethiopians, and purple nutsedge (Cyperus rotundus L.) is one of the commonest and most abundant weeds in tef. Thus, two experiments were undertaken at three locations, namely, Alem Tena, Debre Zeit and Tullu Bollo in Ethiopia to investigate...

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Main Author: Mohammed Sherif, Ahmed
Format: Thesis
Language:English
English
Published: 2004
Subjects:
Nutgrass - Competition - Teff - Ethiopia - Case studies
Online Access:http://psasir.upm.edu.my/id/eprint/517/1/549741_FP_2004_48.pdf
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spelling my-upm-ir.5172013-05-27T06:48:55Z Competition Effects of Purple Nutsedge (Cyperus Rotundus L.) on Growthand Yield of Tef[Eragrostis Tef (Zucc.) Trotter] in Ethiopia 2004-11 Mohammed Sherif, Ahmed Tef [Eragrostis tef (Zucc.) Trotter] is the staple food of Ethiopians, and purple nutsedge (Cyperus rotundus L.) is one of the commonest and most abundant weeds in tef. Thus, two experiments were undertaken at three locations, namely, Alem Tena, Debre Zeit and Tullu Bollo in Ethiopia to investigate competition effects of purple nutsedge on tef and determine combinations of seeding rates, sowing dates, fertilizer rates and time of weeding for effective control of nutsedge without the use of herbicides. The first experiment in each of the three locations consisted of three levels of tef seeding rates (10, 30 and 50 kg ha-1), fertilizer at rates of 0, 10 & 20 kg N ha-1 and 0, 10.5 & 21 kg P ha-1, in the form of Diammonium Phosphate (DAP) treatments, and nutsedge density (0, 30 and 60 plants m-2). The experiment was 33 factorial in a completely randomized block design with four replicates. The second experiment consisted of three sowing dates delayed by 0, 7 and 15 days and five weed removal treatments (no-weeding, weeded at 2, 4 & 6 weeks after crop emergence and a weed-free check). It was a 3x5 factorial in a completely randomized block design with four replications. The results obtained from this study indicated that tef was more competitive than nutsedge under conditions of stress at low soil fertility and high crop and weed densities. Tef plants under these conditions had fewer tillers, were much taller and produced higher yields. Highest seed rate of 50 kg ha-1 offered a greater competitive advantage to tef. The higher tef seeding rates were associated with higher biomass production, which was strongly and positively correlated with higher grain yield. Under conditions of higher soil fertility with applied fertilizer, purple nutsedge resulted in slightly more aggressive growth and reduced tef plant height and grain yield. A detailed analysis of the specific responses in tef plant height to nutsedge density and biomass in relation to fertilizer levels, tef seeding rates and nutsedge sowing densities showed that at the highest seed rate of 50 kg ha-1 tef was more competitive. There was a stronger trend in tef height increase with an increase in nutsedge density, and there was a strong positive correlation between tef plant height and grain yield (R2=0.75). The data also showed that conditions favoring increase in tiller production was associated with lower grain yield. Increase in panicle length was associated with an increase in spikelet numbers and a corresponding increase in tef grain yields, provided there was no delay in sowing. Sowing delays resulted in shorter panicles, and sowing delays of 7 and 15 days resulted in yield reductions of 59.60 and 68.39%, respectively. In general, tef was more competitive than purple nutsedge at all three experimental sites. In summary, crop seeding rates of between 30 and 50 kg ha-1, fertilizer rates of 10 & 20 kg N ha-1 and 10.5 & 21 kg P ha-1, and keeping the tef field free of weeds for at least six weeks and early sowing of tef would enhance farm yields. However, the prevailing environmental conditions may have also favored the survival and more aggressive growth of tef compared to nutsedge, probably due to the remarkable tolerance of tef to low moisture stress than nutsedge. Therefore, the competitiveness of tef against nutsedge needs to be further investigated under more favorable soil moisture conditions. Nutgrass - Competition - Teff - Ethiopia - Case studies 2004-11 Thesis http://psasir.upm.edu.my/id/eprint/517/ http://psasir.upm.edu.my/id/eprint/517/1/549741_FP_2004_48.pdf application/pdf en public phd doctoral Universiti Putra Malaysia Nutgrass - Competition - Teff - Ethiopia - Case studies Faculty of Agriculture English
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
English
topic Nutgrass - Competition - Teff - Ethiopia - Case studies
spellingShingle Nutgrass - Competition - Teff - Ethiopia - Case studies


Mohammed Sherif, Ahmed
Competition Effects of Purple Nutsedge (Cyperus Rotundus L.) on Growthand Yield of Tef[Eragrostis Tef (Zucc.) Trotter] in Ethiopia
description Tef [Eragrostis tef (Zucc.) Trotter] is the staple food of Ethiopians, and purple nutsedge (Cyperus rotundus L.) is one of the commonest and most abundant weeds in tef. Thus, two experiments were undertaken at three locations, namely, Alem Tena, Debre Zeit and Tullu Bollo in Ethiopia to investigate competition effects of purple nutsedge on tef and determine combinations of seeding rates, sowing dates, fertilizer rates and time of weeding for effective control of nutsedge without the use of herbicides. The first experiment in each of the three locations consisted of three levels of tef seeding rates (10, 30 and 50 kg ha-1), fertilizer at rates of 0, 10 & 20 kg N ha-1 and 0, 10.5 & 21 kg P ha-1, in the form of Diammonium Phosphate (DAP) treatments, and nutsedge density (0, 30 and 60 plants m-2). The experiment was 33 factorial in a completely randomized block design with four replicates. The second experiment consisted of three sowing dates delayed by 0, 7 and 15 days and five weed removal treatments (no-weeding, weeded at 2, 4 & 6 weeks after crop emergence and a weed-free check). It was a 3x5 factorial in a completely randomized block design with four replications. The results obtained from this study indicated that tef was more competitive than nutsedge under conditions of stress at low soil fertility and high crop and weed densities. Tef plants under these conditions had fewer tillers, were much taller and produced higher yields. Highest seed rate of 50 kg ha-1 offered a greater competitive advantage to tef. The higher tef seeding rates were associated with higher biomass production, which was strongly and positively correlated with higher grain yield. Under conditions of higher soil fertility with applied fertilizer, purple nutsedge resulted in slightly more aggressive growth and reduced tef plant height and grain yield. A detailed analysis of the specific responses in tef plant height to nutsedge density and biomass in relation to fertilizer levels, tef seeding rates and nutsedge sowing densities showed that at the highest seed rate of 50 kg ha-1 tef was more competitive. There was a stronger trend in tef height increase with an increase in nutsedge density, and there was a strong positive correlation between tef plant height and grain yield (R2=0.75). The data also showed that conditions favoring increase in tiller production was associated with lower grain yield. Increase in panicle length was associated with an increase in spikelet numbers and a corresponding increase in tef grain yields, provided there was no delay in sowing. Sowing delays resulted in shorter panicles, and sowing delays of 7 and 15 days resulted in yield reductions of 59.60 and 68.39%, respectively. In general, tef was more competitive than purple nutsedge at all three experimental sites. In summary, crop seeding rates of between 30 and 50 kg ha-1, fertilizer rates of 10 & 20 kg N ha-1 and 10.5 & 21 kg P ha-1, and keeping the tef field free of weeds for at least six weeks and early sowing of tef would enhance farm yields. However, the prevailing environmental conditions may have also favored the survival and more aggressive growth of tef compared to nutsedge, probably due to the remarkable tolerance of tef to low moisture stress than nutsedge. Therefore, the competitiveness of tef against nutsedge needs to be further investigated under more favorable soil moisture conditions.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Mohammed Sherif, Ahmed
author_facet Mohammed Sherif, Ahmed
author_sort Mohammed Sherif, Ahmed
title Competition Effects of Purple Nutsedge (Cyperus Rotundus L.) on Growthand Yield of Tef[Eragrostis Tef (Zucc.) Trotter] in Ethiopia
title_short Competition Effects of Purple Nutsedge (Cyperus Rotundus L.) on Growthand Yield of Tef[Eragrostis Tef (Zucc.) Trotter] in Ethiopia
title_full Competition Effects of Purple Nutsedge (Cyperus Rotundus L.) on Growthand Yield of Tef[Eragrostis Tef (Zucc.) Trotter] in Ethiopia
title_fullStr Competition Effects of Purple Nutsedge (Cyperus Rotundus L.) on Growthand Yield of Tef[Eragrostis Tef (Zucc.) Trotter] in Ethiopia
title_full_unstemmed Competition Effects of Purple Nutsedge (Cyperus Rotundus L.) on Growthand Yield of Tef[Eragrostis Tef (Zucc.) Trotter] in Ethiopia
title_sort competition effects of purple nutsedge (cyperus rotundus l.) on growthand yield of tef[eragrostis tef (zucc.) trotter] in ethiopia
granting_institution Universiti Putra Malaysia
granting_department Faculty of Agriculture
publishDate 2004
url http://psasir.upm.edu.my/id/eprint/517/1/549741_FP_2004_48.pdf
_version_ 1747810239383601152

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