Titre du document / Document title

Evapotranspiration-based misting control for poinsettia propagation

Auteur(s) / Author(s)

ZOLNIER S. ⁽¹⁾ ; GATES R. S. ⁽²⁾ ; GENEVE R. L. ⁽³⁾ ; BUXTON J. W. ⁽³⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Department, Federal University of Viçosa, Minas Gerais, BRESIL
⁽²⁾ Biosystems and Agricultural Engineering Department, University of Kentucky, Lexington, Kentucky, ETATS-UNIS
⁽³⁾ Department of Horticulture, University of Kentucky, Lexington, Kentucky, ETATS-UNIS

Résumé / Abstract

Theoretical development and validation of a model-based misting control system for propagating poinsettias (Euphorbia pulcherrima 'Freedom Dark Red' Willd. ex Klotzsch) are presented. The control system predicts evapotranspiration (ET) using the Penman-Monteith combination model, with the canopy surface resistance term replaced by an equivalent surface resistance that includes the combined resistance effects of plant stomata, water uptake, propagation medium, and leaf adaxial surfaces. Different combinations of incident radiation (R_i) and air vapor pressure deficit (VPD_air) were used to validate this technique by comparing measured and estimated values of ET of partially rooted cuttings under partially wetted conditions. Under dark conditions, four ranges of VPD_air were applied (0.8 to 1.1, 1.3 to 1.6, 1.8 to 2.1, and 2.3 to 2.6 kPa). Under light conditions, three levels of R_i (100, 200, and 300 W m^-2) were combined with three ranges of VPD_air (1.3 to 1.6, 1.8 to 2.1, and 2.3 to 2.6 kPa). Observed and predicted values of ET under dark conditions were in remarkable agreement, with the ET model overestimating actual ET by 6% and 8% at root emergence and after one week, respectively. During light conditions, predicted ET was at most 14% larger than observed values. The use of predicted ET in misting control for propagation of vegetative cuttings has several advantages over other techniques, such as timer-based scheduling and techniques that account for only R_i or VPD_air, by applying only enough water to maintain water status of the cutting.

Revue / Journal Title

Transactions of the ASAE   ISSN 0001-2351   CODEN TAAEAJ 

Source / Source

2003, vol. 46, n^o1, pp. 135-145 [11 page(s) (article)] (19 ref.)

Langue / Language

Anglais

Editeur / Publisher

American Society of Agricultural Engineers, St. Joseph, MI, ETATS-UNIS  (1958-2005) (Revue)

Mots-clés anglais / English Keywords

Application method ; Ornamental crop ; Spermatophyta ; Angiospermae ; Dicotyledones ; Euphorbiaceae ; Misting ; Euphorbia pulcherrima ; Model study ; Modeling ; Stomata ; Surface resistance ; Vapor pressure ; Vegetative propagation ; Control system ; Evapotranspiration ; Cropping system ;

Mots-clés français / French Keywords

Mots-clés espagnols / Spanish Keywords

Modalidad tratamiento ; Planta ornamental ; Spermatophyta ; Angiospermae ; Dicotyledones ; Euphorbiaceae ; Euphorbia pulcherrima ; Estudio sobre modelo ; Modelización ; Estoma ; Resistencia superficial ; Presión vapor ; Multiplicación vegetativa ; Sistema control ; Evapotranspiración ; Sistema cultural ;

Mots-clés d'auteur / Author Keywords

Evapotranspiration ; Misting control ; Poinsettia propagation ; Vapor pressure deficit ;

Localisation / Location

INIST-CNRS, Cote INIST : 2869, 35400010987098.0130