1. Environmental Control Systems Evolution, Current Systems, the Future Click on images to go to original URL

2. What can be regulated? Temperature (heat/cooling systems) Humidity Supplemental Lighting Photoperiod (day length extension or black cloth) Atmospheric composition (CO 2 enrichment) Irrigation Nutrient Delivery (Fertilization)

3. Types of Controls Manual On/off Switches Step Controllers Dedicated Microprocessors Computers (Integrated Control)

4. Manual Greenhouse Control Common before 1950 to have people 24/7 to monitor temperature (winter) Manual ventilation, heat valves Manual pulling of shade cloth Manual sun shades Hand watering

6. On/Off Switches Simple For heating and cooling based on a thermostat Problems with accuracy May still be suitable for simple season extension houses Many styles and manufacturers available

7. Step Controller Advancement over on/off switch Instead of just one option there are multiple stages possible (for example) Stage 1 – louvered vent opens Stage 2 – exhaust fan on opposite wall on low speed Stage 3 – exhaust fan on opposite wall on high speed Not expandable Not good for complicated temperature control schemes Can be difficult to ‘set up’ and ‘change’

9. Dedicated Microprocesssors

10. Computers Despite cost effectiveness and ease of use 85% of greenhouses still have some manual controls Cost 5 to 7K and up Very expandable System can grow with your operation Data can be easily made available to others for troubleshooting Integrated record keeping

12. IFAC TECHNICAL BOARD AUGUST, 2003 IFAC EMERGING AREAS PROJECT CC 8: BIO & ECOLOGICAL SYSTEMS (APPLICATIONS) Keith Godfrey (for Ewart Carson)

13. TC 8.1 Control and Automation in Agriculture “Speaking animals” Automated measurement of the responses of individual animals to differing feeding and climate regimes so as to optimise their management “Speaking plants” Automated measurement of plant responses to different treatments for the purpose of automatic control of processes in the soil-substrate-plant continuum Automation of harvesting and handling of crops Developments required due to a lack of skilled, affordable labour Automation for tracking and tracing of products and of the production condition Stage of maturity, variability, treatments etc.