Evapotranspiration-based misting control for poinsettia propagation

Sérgio Zolnier, Richard S. Gates, Robert L. Geneve, Jack W. Buxton

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


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 (Ri) and air vapor pressure deficit (VPDair) 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 VPDair 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 Ri (100, 200, and 300 Wm-2) were combined with three ranges of VPDair (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 Ri or VPDair, by applying only enough water to maintain water status of the cutting.

Original languageEnglish
Pages (from-to)135-145
Number of pages11
JournalTransactions of the ASABE
Issue number1
StatePublished - Jan 2003


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

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)


Dive into the research topics of 'Evapotranspiration-based misting control for poinsettia propagation'. Together they form a unique fingerprint.

Cite this