The effects of water stress on evapotranspiration and leaf temperatures of two olive (Olea europaea L.) cultivars

Abstract

The evapotranspiration (ET) and leaf temperatures of two olive (Olea europaea L.) cultivars 'Ayvalık' and 'Gemlik' were studied comparatively in fully-irrigated and water-stressed plants. The pot experiment was conducted under field conditions in 2009 and 2010. The experiment consisted of 4 treatments: 1) non water-stressed, 2) mild waterstressed, 3) moderate water-stressed, and 4) fully water-stressed. Leaf temperature (Tc) and ambient air temperature (Ta) of each seedling were measured at midday with an infrared thermometer and psychrometer respectively, and Tc-Ta was assessed. It was found that the irrigation water requirement of 'Gemlik' olive seedlings exceeded that of 'Ayvalık' olive seedlings. Tc-Ta was highest in the fully water-stressed treatment and lowest in the non water-stressed treatment for both olive cultivars. In all treatments, the Tc-Ta of 'Gemlik' was higher than that of 'Ayvalık'. The relationship between Tc-Ta and ET was linear and the coefficients of determination (R 2 = 0.72-0.74 for 'Ayvalık', R 2 = 0.62-0.72 for 'Gemlik' according to the analysis of linear regression) were statistically significant at p < 0.001 for both cultivars. The study showed that leaf temperature changed depending on ET in both olive cultivars and that an infrared thermometer can be used for measuring daily ET in olive seedlings.

An Overview of Olive Cultivation in Turkey: Botanical Features, Eco-Physiology and Phytochemical Aspects

“…Olive cultivation in Turkey is usually carried out on slopes or very difficult terrain, and such plants will suffer from high temperatures and lack of water following the future scenarios of global warming [205]. Olive trees growing especially in arid and semi-arid regions too will be affected in particular by global climate change and water stress [206]. If agricultural production in general goes down, this will have serious consequences on the economies of olive producing countries as well.…”

Physiological and molecular responses to drought stress in teak (Tectona grandis L.f.)

“…Here, the RWC intensification under moderate stress treatment compared with control treatment can be explained by the high transpiration rate and high maximum temperature at the collection date (38°C), which may have caused a leaf transpiration outbreak during tissue preparation and photographing. This also explains the great RWC variability in the control plants, since both moderate and severe drought stress plants remained with their stomata closed during the collection day, and therefore the transpiration rate was less influenced by the air temperature and humidity [64]. Also, the RWC reduction can be positively correlated with the photosynthetic rate reduction and with the compatible solutes enhancement [65].…”

Implications of atmospheric conditions for analysis of surface temperature variability derived from landscape-scale thermography

“…Huge differences in temperature between a vegetated surface and the air above it may occur at times with (i) a high energy input, especially due to high incoming shortwave radiation (Kahmen et al 2011; Lambers et al 1998; Martin et al 1999; Wilson et al 1987), (ii) a low transpirational cooling due to water limitation (Camoglu 2013; Fuchs 1990; Gates 1964; Jackson et al 1981), and (iii) low atmosphere-vegetation coupling (Jones 1992; McNaughton and Jarvis 1983). …”