Hemp for textiles

plant size matters

W. Westerhuis

Research output: Thesisinternal PhD, WU

Abstract

Abstract

Key words: Cannabis sativa L., day length sensitivity, fibre hemp, genotype, harvest time, plant density, plant weight, primary fibres, secondary fibres, sowing date, textiles.

Westerhuis, W. (2016) Hemp for textiles: plant size matters, PhD thesis. Wageningen University, Wageningen, The Netherlands, 234 pp. With English and Dutch summaries. 

Fibre hemp (Cannabis sativa L.) may be an alternative to cotton and synthetic fibres as a raw material for textile yarn production in the European Union. The agronomic options to manipulate plant development and crop growth with the aim to optimise hemp long fibre production were investigated. Field trials with factors sowing density, sowing date, harvest time and variety were conducted. Stems were traditionally processed by retting, drying, breaking, and scutching. Following standard protocols, almost 1500 hemp stem samples were analysed. Varieties differ widely in their fibre content, but this thesis shows that when variety and plant size are known, the amounts of fibres, wood, and retting losses are known. The dry weight of the stems at harvest, not the factors underlying this weight, are determinant. In retted stems the dry matter is split–up into fibres and wood in a fixed way. The options to manipulate this ratio by crop management, given variety, are very small and for practical reasons they can be neglected. In fibre hemp two bast fibre types occur. Primary or long fibres are valuable for yarn spinning. Secondary fibres are too short and their presence hampers the production of fine yarns. This thesis shows that the secondary fibre front height increases with plant weight. Although a causal relationship between secondary fibre formation and flowering does not exist, the secondary fibre front is found higher in flowering plants when compared to non–flowering plants of the same height. This is likely to be caused by the higher weight or momentum of flowering plants as compared with non–flowering plants of the same height. Consequently, a harvest before flowering is preferable. This was shown in a greenhouse experiment, in which the short–day response of hemp was used to create size ranges of flowering and non–flowering plants. To produce high–quality raw materials for textile production, short crops should be grown. The options to produce plants with the desired size are manifold. Since sowing density, sowing date, and harvest time do not have an additional effect on the primary fibre content besides the indirect effect through stem weight, any combination of these factors could be chosen to optimize plant size.

 

 

Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Struik, Paul, Promotor
  • Stomph, Tjeerd-Jan, Co-promotor
  • van Dam, Jan, Co-promotor
Award date20 May 2016
Place of PublicationWageningen
Publisher
Print ISBNs9789462577879
DOIs
Publication statusPublished - 2016

Fingerprint

hemp
yarns
sowing date
stems
retting
Cannabis sativa
flowering
fiber content
raw materials
Angiospermae
sowing
synthetic fibers
wood fibers
lint cotton
momentum
crop management
crops
spinning
greenhouse experimentation
plant density

Keywords

  • cannabis sativa
  • fibre plants
  • textile fibres
  • textiles
  • photoperiod
  • hemp
  • plant fibres
  • plant density
  • harvesting date
  • sowing date
  • biobased materials

Cite this

Westerhuis, W. (2016). Hemp for textiles: plant size matters. Wageningen: Wageningen University. https://doi.org/10.18174/378698
Westerhuis, W.. / Hemp for textiles : plant size matters. Wageningen : Wageningen University, 2016. 234 p.
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abstract = "Abstract Key words: Cannabis sativa L., day length sensitivity, fibre hemp, genotype, harvest time, plant density, plant weight, primary fibres, secondary fibres, sowing date, textiles. Westerhuis, W. (2016) Hemp for textiles: plant size matters, PhD thesis. Wageningen University, Wageningen, The Netherlands, 234 pp. With English and Dutch summaries.  Fibre hemp (Cannabis sativa L.) may be an alternative to cotton and synthetic fibres as a raw material for textile yarn production in the European Union. The agronomic options to manipulate plant development and crop growth with the aim to optimise hemp long fibre production were investigated. Field trials with factors sowing density, sowing date, harvest time and variety were conducted. Stems were traditionally processed by retting, drying, breaking, and scutching. Following standard protocols, almost 1500 hemp stem samples were analysed. Varieties differ widely in their fibre content, but this thesis shows that when variety and plant size are known, the amounts of fibres, wood, and retting losses are known. The dry weight of the stems at harvest, not the factors underlying this weight, are determinant. In retted stems the dry matter is split–up into fibres and wood in a fixed way. The options to manipulate this ratio by crop management, given variety, are very small and for practical reasons they can be neglected. In fibre hemp two bast fibre types occur. Primary or long fibres are valuable for yarn spinning. Secondary fibres are too short and their presence hampers the production of fine yarns. This thesis shows that the secondary fibre front height increases with plant weight. Although a causal relationship between secondary fibre formation and flowering does not exist, the secondary fibre front is found higher in flowering plants when compared to non–flowering plants of the same height. This is likely to be caused by the higher weight or momentum of flowering plants as compared with non–flowering plants of the same height. Consequently, a harvest before flowering is preferable. This was shown in a greenhouse experiment, in which the short–day response of hemp was used to create size ranges of flowering and non–flowering plants. To produce high–quality raw materials for textile production, short crops should be grown. The options to produce plants with the desired size are manifold. Since sowing density, sowing date, and harvest time do not have an additional effect on the primary fibre content besides the indirect effect through stem weight, any combination of these factors could be chosen to optimize plant size.    ",
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publisher = "Wageningen University",
school = "Wageningen University",

}

Westerhuis, W 2016, 'Hemp for textiles: plant size matters', Doctor of Philosophy, Wageningen University, Wageningen. https://doi.org/10.18174/378698

Hemp for textiles : plant size matters. / Westerhuis, W.

Wageningen : Wageningen University, 2016. 234 p.

Research output: Thesisinternal PhD, WU

TY - THES

T1 - Hemp for textiles

T2 - plant size matters

AU - Westerhuis, W.

N1 - WU thesis 6354

PY - 2016

Y1 - 2016

N2 - Abstract Key words: Cannabis sativa L., day length sensitivity, fibre hemp, genotype, harvest time, plant density, plant weight, primary fibres, secondary fibres, sowing date, textiles. Westerhuis, W. (2016) Hemp for textiles: plant size matters, PhD thesis. Wageningen University, Wageningen, The Netherlands, 234 pp. With English and Dutch summaries.  Fibre hemp (Cannabis sativa L.) may be an alternative to cotton and synthetic fibres as a raw material for textile yarn production in the European Union. The agronomic options to manipulate plant development and crop growth with the aim to optimise hemp long fibre production were investigated. Field trials with factors sowing density, sowing date, harvest time and variety were conducted. Stems were traditionally processed by retting, drying, breaking, and scutching. Following standard protocols, almost 1500 hemp stem samples were analysed. Varieties differ widely in their fibre content, but this thesis shows that when variety and plant size are known, the amounts of fibres, wood, and retting losses are known. The dry weight of the stems at harvest, not the factors underlying this weight, are determinant. In retted stems the dry matter is split–up into fibres and wood in a fixed way. The options to manipulate this ratio by crop management, given variety, are very small and for practical reasons they can be neglected. In fibre hemp two bast fibre types occur. Primary or long fibres are valuable for yarn spinning. Secondary fibres are too short and their presence hampers the production of fine yarns. This thesis shows that the secondary fibre front height increases with plant weight. Although a causal relationship between secondary fibre formation and flowering does not exist, the secondary fibre front is found higher in flowering plants when compared to non–flowering plants of the same height. This is likely to be caused by the higher weight or momentum of flowering plants as compared with non–flowering plants of the same height. Consequently, a harvest before flowering is preferable. This was shown in a greenhouse experiment, in which the short–day response of hemp was used to create size ranges of flowering and non–flowering plants. To produce high–quality raw materials for textile production, short crops should be grown. The options to produce plants with the desired size are manifold. Since sowing density, sowing date, and harvest time do not have an additional effect on the primary fibre content besides the indirect effect through stem weight, any combination of these factors could be chosen to optimize plant size.    

AB - Abstract Key words: Cannabis sativa L., day length sensitivity, fibre hemp, genotype, harvest time, plant density, plant weight, primary fibres, secondary fibres, sowing date, textiles. Westerhuis, W. (2016) Hemp for textiles: plant size matters, PhD thesis. Wageningen University, Wageningen, The Netherlands, 234 pp. With English and Dutch summaries.  Fibre hemp (Cannabis sativa L.) may be an alternative to cotton and synthetic fibres as a raw material for textile yarn production in the European Union. The agronomic options to manipulate plant development and crop growth with the aim to optimise hemp long fibre production were investigated. Field trials with factors sowing density, sowing date, harvest time and variety were conducted. Stems were traditionally processed by retting, drying, breaking, and scutching. Following standard protocols, almost 1500 hemp stem samples were analysed. Varieties differ widely in their fibre content, but this thesis shows that when variety and plant size are known, the amounts of fibres, wood, and retting losses are known. The dry weight of the stems at harvest, not the factors underlying this weight, are determinant. In retted stems the dry matter is split–up into fibres and wood in a fixed way. The options to manipulate this ratio by crop management, given variety, are very small and for practical reasons they can be neglected. In fibre hemp two bast fibre types occur. Primary or long fibres are valuable for yarn spinning. Secondary fibres are too short and their presence hampers the production of fine yarns. This thesis shows that the secondary fibre front height increases with plant weight. Although a causal relationship between secondary fibre formation and flowering does not exist, the secondary fibre front is found higher in flowering plants when compared to non–flowering plants of the same height. This is likely to be caused by the higher weight or momentum of flowering plants as compared with non–flowering plants of the same height. Consequently, a harvest before flowering is preferable. This was shown in a greenhouse experiment, in which the short–day response of hemp was used to create size ranges of flowering and non–flowering plants. To produce high–quality raw materials for textile production, short crops should be grown. The options to produce plants with the desired size are manifold. Since sowing density, sowing date, and harvest time do not have an additional effect on the primary fibre content besides the indirect effect through stem weight, any combination of these factors could be chosen to optimize plant size.    

KW - cannabis sativa

KW - fibre plants

KW - textile fibres

KW - textiles

KW - photoperiod

KW - hemp

KW - plant fibres

KW - plant density

KW - harvesting date

KW - sowing date

KW - biobased materials

KW - cannabis sativa

KW - vezelgewassen

KW - textielvezels

KW - textiel

KW - fotoperiode

KW - hennep

KW - plantenvezels

KW - plantdichtheid

KW - oogsttijdstip

KW - zaaitijd

KW - materialen uit biologische grondstoffen

U2 - 10.18174/378698

DO - 10.18174/378698

M3 - internal PhD, WU

SN - 9789462577879

PB - Wageningen University

CY - Wageningen

ER -

Westerhuis W. Hemp for textiles: plant size matters. Wageningen: Wageningen University, 2016. 234 p. https://doi.org/10.18174/378698