Germination ecology of spiny (Amaranthus spinosus) and slender amaranth (A. viridis): troublesome weeds of direct-seeded rice

Spiny and slender amaranth are troublesome Amaranthaceae species of direct-seeded rice and other upland crops in many Asian countries. Seed germination and seedling emergence response of these species to various environmental factors was determined in laboratory and screenhouse experiments. Germinat...

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Detalles Bibliográficos
Autores principales: Chauhan, Bhagirath S., Johnson, David E.
Formato: Journal Article
Lenguaje:Inglés
Publicado: Cambridge University Press 2009
Materias:
Acceso en línea:https://hdl.handle.net/10568/165121
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author Chauhan, Bhagirath S.
Johnson, David E.
author_browse Chauhan, Bhagirath S.
Johnson, David E.
author_facet Chauhan, Bhagirath S.
Johnson, David E.
author_sort Chauhan, Bhagirath S.
collection Repository of Agricultural Research Outputs (CGSpace)
description Spiny and slender amaranth are troublesome Amaranthaceae species of direct-seeded rice and other upland crops in many Asian countries. Seed germination and seedling emergence response of these species to various environmental factors was determined in laboratory and screenhouse experiments. Germination in both species was stimulated by 35/25 and 30/20 C fluctuating temperatures and light. Germination of slender amaranth was more sensitive to increasing salt and water stress than spiny amaranth. Spiny amaranth germinated at a NaCl concentration of 100 mM (19%), whereas slender amaranth seeds did not germinate at this concentration. In seed burial trials where the seeds were on the soil surface, emergence was 56 and 68% for spiny amaranth and slender amaranth, respectively. Only 7% of spiny amaranth seedling emerged from a soil depth of 0.5 cm, whereas no emergence was observed for 4 cm or deeper. For slender amaranth, 6 and 0% emergence was observed at 4 and 6 cm, respectively. Seedling emergence of spiny amaranth was affected more by high rates of rice residue than slender amaranth. Greater quantities of residue than those normally found in rice fields were required to significantly reduce weed densities.
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spelling CGSpace1651212024-12-19T14:12:36Z Germination ecology of spiny (Amaranthus spinosus) and slender amaranth (A. viridis): troublesome weeds of direct-seeded rice Chauhan, Bhagirath S. Johnson, David E. weeds amaranthus spinosus amaranthus viridis germination ecology direct sowing Spiny and slender amaranth are troublesome Amaranthaceae species of direct-seeded rice and other upland crops in many Asian countries. Seed germination and seedling emergence response of these species to various environmental factors was determined in laboratory and screenhouse experiments. Germination in both species was stimulated by 35/25 and 30/20 C fluctuating temperatures and light. Germination of slender amaranth was more sensitive to increasing salt and water stress than spiny amaranth. Spiny amaranth germinated at a NaCl concentration of 100 mM (19%), whereas slender amaranth seeds did not germinate at this concentration. In seed burial trials where the seeds were on the soil surface, emergence was 56 and 68% for spiny amaranth and slender amaranth, respectively. Only 7% of spiny amaranth seedling emerged from a soil depth of 0.5 cm, whereas no emergence was observed for 4 cm or deeper. For slender amaranth, 6 and 0% emergence was observed at 4 and 6 cm, respectively. Seedling emergence of spiny amaranth was affected more by high rates of rice residue than slender amaranth. Greater quantities of residue than those normally found in rice fields were required to significantly reduce weed densities. 2009-08 2024-12-19T12:54:43Z 2024-12-19T12:54:43Z Journal Article https://hdl.handle.net/10568/165121 en Cambridge University Press Chauhan, Bhagirath S.; Johnson, David E. 2009. Germination ecology of spiny (Amaranthus spinosus) and slender amaranth (A. viridis): troublesome weeds of direct-seeded rice. Weed sci., Volume 57 no. 4 p. 379-385
spellingShingle weeds
amaranthus spinosus
amaranthus viridis
germination
ecology
direct sowing
Chauhan, Bhagirath S.
Johnson, David E.
Germination ecology of spiny (Amaranthus spinosus) and slender amaranth (A. viridis): troublesome weeds of direct-seeded rice
title Germination ecology of spiny (Amaranthus spinosus) and slender amaranth (A. viridis): troublesome weeds of direct-seeded rice
title_full Germination ecology of spiny (Amaranthus spinosus) and slender amaranth (A. viridis): troublesome weeds of direct-seeded rice
title_fullStr Germination ecology of spiny (Amaranthus spinosus) and slender amaranth (A. viridis): troublesome weeds of direct-seeded rice
title_full_unstemmed Germination ecology of spiny (Amaranthus spinosus) and slender amaranth (A. viridis): troublesome weeds of direct-seeded rice
title_short Germination ecology of spiny (Amaranthus spinosus) and slender amaranth (A. viridis): troublesome weeds of direct-seeded rice
title_sort germination ecology of spiny amaranthus spinosus and slender amaranth a viridis troublesome weeds of direct seeded rice
topic weeds
amaranthus spinosus
amaranthus viridis
germination
ecology
direct sowing
url https://hdl.handle.net/10568/165121
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