Effect of terminal drought on yield and some physiological traits of winter wheat

Abstract

Terminal drought i.e. drought during grain-filling phase is the most devastating environmental stress to wheat production. In present study the effect of terminal drought on physiological traits and its influence on yield and yield components in two winter wheat varieties (Kuna and Karla) were investigated. Terminal drought stress was applied from the beginning of anthesis by installing mobile plastic roof above the crops. Leaf gas exchange parameters, chlorophyll content index (CCI), relative water content (RWC), and nitrogen (N) content were measured three times during grain-filling phase, at early milk maturity (EMM), late milk maturity (LMM), and at early wax maturity (EWM). Grain yield and 1000 grain weight were measured by harvesting of each plot at crop maturity. Terminal drought enhanced leaf senescence and caused reduction of RWC, CCI, net photosynthetic rate (A), stomatal conductance (gs), and transpiration rate (E) as well as, grain yield and all measured yield components. However, grain yield and grain weight per ear were less affected in Karla indicating enhanced tolerance to terminal drought compared to Kuna variety. Higher tolerance to terminal drought in Karla is based on staygreen strategy. Stay-green strategy in Karla was characterized by retention of CCI at early wax maturity, which contributed to higher E and lower intercellular CO2 concentration compared to Kuna under terminal drought. Stay-green strategy as trait that enhanced terminal drought tolerance in Karla should be used in breeding programs and utilized to ensure maximum economic yields under terminal drought conditions.

Morpho-physiological and biochemical response of wheat to various treatments of silicon nano-particles under drought stress conditions

“…Moreover, the estimated production of wheat was 24.946 million tons in 2019 which was 2.5% higher than the previous year 13,14 . Over half of the world's wheat fields are influenced by periodic drought stress 15 . The rapid climate change and global warming have the worst impact on the crops in the future because it enhances the frequency and intensity of drought due to less rainfall and high temperature on earth 16 .…”

The performance of new early maturing pro-vitamin A maize (Zea mays L.) hybrids in the derived savanna agro-ecology of Nigeria

“…This situation is worsened by the rising impact of global climate change, compelling maize production into marginal, drought-prone zones (Bello et al, 2012). Terminal drought during grain-filling growth phases can be devastating in maize breeding as a result of enhancing leaf senescence, reduction in leaf gas exchange parameters, chlorophyll content of the plant and consequently a reduction in grain yield (Habuš-Jerčić et al, 2018). With the occurrence of random drought in the derived savanna, early maturing maize genotypes that can avoid drought and other stress factors at flowering could be important in reducing losses (Olaoye et al, 2009;Hussain, 2011).…”