Leaf Temperature as an Index to Determine the Irrigation Interval

Subject Areas : Research On Crop Ecophysiology

ABDOLREZA EGHTEDARI NAEENI ¹ , ELHAM MOHRI ESFAHANI ² , MOHSEN BEIGI HARCHEGANI ³ , MEHRDAD JAFARPOUR ⁴ , MARYAM GOLABADI ⁵

1 - Faculty of Agriculture Engineering, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran
2 - Faculty of Agriculture Engineering, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran
3 - Tiran Branch, Islamic Azad University, Isfahan, Iran.
4 - Faculty of Agriculture Engineering, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran
5 - Faculty of Agriculture Engineering, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran

Accepted : 2017-10-17 Published : 2014-06-01

Keywords:

Abstract :

ABDOLREZA EGHTEDARI NAEENI1*, ELHAM MOHRI ESFAHANI1, MOHSEN BEIGI HARCHEGANI2, MEHRDADJAFARPOUR1, MARYAM GOLABADI11- Faculty of Agriculture Engineering, Isfahan (Khorasgan) Branch, Islamic Azad University,Isfahan, Iran2- Tiran Branch, Islamic Azad University, Isfahan, Iran.
Corresponding author Email: [e-mail]: 10 January 2014 Accepted: 25 April 2014ABSTRACT Abstract Evapotranspiration and plant water absorption reduce when exposed to water stress and this reduction results in an increase in leaf temperature. To determine the effect of water stress on leaf temperature and timing of irrigation using leaf temperature, a research was conducted on the Research and Education Greenhouse Production Center of Islamic Azad University, Isfahan Branch (Khorasgan). This study was conducted in controlled conditions and soilless culture of cucumber, tomato, pepper and strawberry. The index of difference between the temperature of air and leaf (ΔT= TAir –TLeaf ) showed leaf temperature which then could indicate the amount of water absorbed by the root therefore, transpiration rates were measured. With an acceptable coefficient of determination model, we concluded that this index (difference between the temperature of air and leaf) was dependent on the intake of water from the roots and leaf transpiration rate, so it can be used as an indicator to determine the time of irrigation. Abbreviation: VPD: Vapor Pressure Deficit, PAR: Photosynthetically Active Radiation, RH: Relative Humidity, ΔT = TAir –TLeaf.