Infrared Thermal Imaging as Innovative Techniques with Eco-physiological Traits for Monitoring Water Stress in Wheat

Document Type : Original Article

Authors

1 Agronomy Department, Faculty of Agriculture, Suez Canal University, 41522 Ismailia, Egypt

2 Botany Department, Faculty of Agriculture, Suez Canal University, 41522 Ismailia, Egypt

Abstract

The association of Infrared thermal imaging and specific target traits for drought tolerance (presence of awns,
Normalized Difference Vegetative Index (NDVI), Relative Water Content (RWC), leaf area) with yield performance
under three water regimes was analyzed utilizing wheat genotypes in two seasons (2012/2013 and 2013/2014). In this
study eight genotypes of bread wheat were used for screening them under three water regimes; control 100% Field
Capacity (FC), 75% FC and 50% FC. The presence of awns had a significant effect on yield loss under drought amongst
wheat genotypes. Moreover, an infrared crop water stress index was calculated in the main water requirement stage.
RWC was determined to give indication on the plant water status during the experiment. RWC ranged from 47.2% to
76.5% for water stress (50% FC). NDVI ranged from 0.31 (Maser 2) to 0.49 (H2) under water stress 50% FC. This
result indicated that hybrid (H2) had the greatest green biomass and could be considered as a drought tolerant genotype.
Temperatures of canopies can be used as indicators of stomatal closure in response to soil water deficit. It was found
that thermal imaging can distinguish between stressed and non-stressed canopies, and even between deficit water
treatments. Leaf temperature (T leaf) varied between water stress treatments and among the wheat genotypes within the
same water treatment. Where, T leaf was ranged from 21.9 to 25.3°C for 50% FC treatment. Similar observations were
noticed for the other water treatments. Indicating that the other physiological mechanism could be influenced on the
behavior of genotypes due to water stress and subsequently leaf temperature was affected. Variation of the distribution
of temperatures within canopies was found to be a reliable indicator of water stress. It could be concluded that
combining thermal camera technology with physiological traits was sufficiently to predict wheat production under
water stress.

Keywords