Greenhouse Canada


OMAFRA CEA Series: Plant Empowerment Workshop

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May 27 - May 28, 2021

Title: Plant Empowerment Workshop


  • Dr. Peter van Weel, co-author of Plant Empowerment — The Basic Principles
  • Ton Habraken, greenhouse climate adviser, Ludvig Svensson
  • René Beerkens, greenhouse climate consultant and trainer, Hoogendoorn Growth Management
  • Evripidis Papadopoulos, data analyst,

Date and Time:

Thursday, May 27, 2021, 9:00 AM -12:30 PM EST

Friday, May 28, 2021, 9:00 AM — 1:15 PM EST

Where: Zoom



Day 1: Introduction to the theory of Plant Empowerment (Dr. Peter van Weel)

Thursday, May 27, 2021 (9:00 AM-12:30 PM EST)

9:00–10:15 AM EST

Basic knowledge about physics and physiology that play an important role in a greenhouse and for plants:

  • The interaction between the main resources: CO2, light, water, RH and temperature.
  • The energy balance and stomata opening.
  • The role of air movement and ventilation in climate uniformity and physiology.
  • The role of heat emission in the dark.

10:15–10:30 AM EST

Question and Answer

10:30–10:45 AM EST


10:45 AM -12:00 PM EST

Plant Empowerment, from experience-based control to sensor-based control:

  • Controlling 6 balances instead of climate. Why are they important?
  • Why and how reduction of transpiration under intense light can increase photosynthesis.
  • Why is transpiration control in the dark better than RH or VD control?
  • Prevention of fungal diseases with better screen management.

12:00–12:30 PM EST

Question and Answer

Day 2: Practical Application of Plant Empowerment. (Dr. Peter van Weel)

Friday, May 28, 2021, 9:00 AM — 1:15 PM EST

  1. Introduction to sensors, software tools and the value of data analysis:
  • A new generation of sensors: leaf temperature and tissue temperature, net absorbed radiation, and the microclimate.
  • Measure energy balance to control transpiration, stomata opening and water balance.
  • The RTR tool (ratio temperature to radiation) to control plant balance.
  • Demonstration of the radiation monitor tool: the effect of energy screens on the greenhouse climate, transpiration, energy consumption and plant conditions.
  • Demonstration of the GPE simulation tool: how can I use the hardware components such as screens, light, air tubes, air circulation or ventilation fans and windows in an integrated way?

2. The autonomous greenhouse.

10:30–11:00 AM EST

Question and Answer

11:00–11:15 AM EST


11:15 AM-12:45 PM EST

  1. How can the 6 balances assist in obtaining positive effects of light abatement screens (Ton Habraken and René Beerkens).

2. How do I start with the RTR tool? (Evripidis Papadopoulos).


Question and Answer

Contact: Dr. Fadi Al-Daoud, Greenhouse Vegetable Specialist

Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)


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