INCORPORATION OF A MODEL TO PREDICT CROP TRANSPIRATION IN A COMMERCIAL IRRIGATION EQUIPMENT AS A CONTROL METHOD FOR WATER SUPPLY TO SOILLESS HORTICULTURAL CROPS

Irrigation control in protected soilless culture can be based on the use of climate parameters and crop development to predict water requirements.
This estimate, generally based on the Penman-Monteith equation, could be conditioned by the availability of coefficient values from different climatic regions and the approach to LAI evolution.
In this study we propose two methods to adjust the P-M equation to the water requirements of a soilless tomato crop under greenhouse conditions where crop development was estimated by means of: i) A regression in function on the days after transplanting corrected using the daily drain flow measured with a tipping-bucket flow sensor and ii) the LAI prediction in function on the inside greenhouse daily thermal time.
Based on these transpiration estimates, the irrigation methods were tested and compared to current irrigation practices.
All irrigation managements showed the same water use efficiency but the method i) needed fewer human intervention, during the 202 days of crop cycle, than the others irrigation methods.
The use of a transpiration model, together with on-line information of changes in leaf are provide an accurate irrigation method for soilless crop production which canopy is continuously modified.

International Symposium on High Technology for Greenhouse System Management: Greensys2007

E. Medrano, F.J. Alonso, MA. Cruz Sánchez-Guerrero, P. Lorenzo

LAI, greenhouse, water use efficiency, radiation, VPD

https://doi.org/10.17660/ActaHortic.2008.801.162