The Effect of Supplemental Irrigation on Canopy Temperature Depression, Chlorophyll Content, and Water Use Efficiency in Three Wheat (Triticum aestivum L. and T. durum Desf.) Varieties Grown in Dry Regions of Jordan

Abstract

Abstract:One critical challenge facing the world is the need to satisfy the food requirements of the dramatically growing population. Drought stress is one of the main limiting factors in the wheat-producing regions; therefore, wheat yield stability is a major objective of wheat-breeding programs in Jordan, which experience fluctuating climatic conditions in the context of global climate change. In the current study, a two-year field experiment was conducted for exploring the effect of four different water regimes on the yield, yield components, and stability of three wheat (Triticum aestivum L.; T. durum Desf.) Jordanian cultivars as related to Canopy Temperature Depression (CTD), and Chlorophyll Content (measured by Soil-Plant Analysis Development, SPAD). A split plot design was used in this experiment with four replicates. Water treatment was applied as the main factor: with and without supplemental irrigation; 0%, 50%, 75%, and 100% of field capacity were applied. Two durum wheat cultivars and one bread wheat cultivar were split over irrigation treatments as a sub factor. In both growing seasons, supplemental irrigation showed a significant increase in grain yield compared to the rain-fed conditions. This increase in grain yield was due to the significantly positive effect of water availability on yield components. Values of CTD, SPAD, harvest index, and water use efficiency (WUE) were increased significantly with an increase in soil moisture and highly correlated with grain yield. Ammon variety produced the highest grain yield across the four water regimes used in this study. This variety was characterized by the least thermal time to maturity and the highest values of CTD and SPAD. It was concluded that Ammon had the highest stability among the cultivars tested. Furthermore, CTD and SPAD can be used as important selection parameters in breeding programs in Jordan to assist in developing high-yielding genotypes under drought and heat stress conditions.

Response of Growth, Productivity and Quality of Some Egyptian Wheat Cultivars to Different Irrigation Regimes

“…The superiority of growth traits, total chlorophyll and phenological development stages obtained herein at full irrigation regime (five irrigations) may be due to that the sufficient soil moisture in the root zone help the plants to absorb greater amount of water and nutrients which enhancing internodes elongation and cell division as well as improving pigments and photosynthetic process and metabolites accumulation and consequently increased growth periods. In this concern, many researchers reported that providing the wheat plants with sufficient moisture caused an increase in plant height (Razaq et al, 2016, Soomro et al, 2016, flag leaf area (El-Metwally et al, 2015), chlorophyll (Abdelraouf et al, 2013 andAl-Ghzawi et al, 2018) and days from sowing till heading and maturity Mekkei &El Haggan, 2014).…”

“…Recently, a great attention has been directed paid to increase the productivity of such important crop, therefore the strategies of agricultural policies have to be focused on minimizing the gap between the Egyptian production and consumption via increasing wheat production through using tolerant genotypes for biotic and abiotic stress circumstances and using the optimal agricultural practices taking into account the limited available water reserves on global scale (Loggini et al, 1999 andVarga et al, 2015). One of the major effects of climate changes particularly in arid and semi-arid regions will be increased frequency and severity of drought stress which is considered the most critical environmental stresses and one of the limiting factors in the wheat-producing regions (IPCC, 2013 andAl-Ghzawi et al, 2018). Water stress can result in a negative impact on phenological growth stages, reduced biomass production and grain yield (Kilic &Yagabsanlar, 2010 andSeleiman et al, 2011).…”

The Use of Appropriate Cultivar of Basil (Ocimum basilicum) Can Increase Water Use Efficiency under Water Stress

“…The trend was similar in all cultivars, and the lowest WUE was found at the d 100 treatment. WUE was affected by the irrigation level and also by the cultivar, which is very important, as, in limited water supply, it is better to find cultivars tolerant to water stress that can efficiently use water [24,25,[45][46][47][48]. In addition, the WUE that was found was much higher than in other species such as maize, and this is because basil and also other aromatic and medicinal plants are not harvested for grains, but they are harvested at full anthesis and do not require water for their whole growth period [46][47][48].…”

Morphological and Ecophysiological Indicators for Coriander Under Irrigation Depths and Nitrogen Levels

“…Possibly, the chlorophyll "b" is more resistant to degradation than chlorophyll "a" and can be an important index of hydric stress. However, contrarily to these results, in literature was observed decreasing in sugarcane (Gonçalves et al, 2017) and wheat (Al-Ghzawi et al, 2018) or not effect in Thymus daenensis (Bahreininejad et al, 2013) on chlorophyll "b" under soil hydric deficit.…”