Two field experiments were conducted at Gemmeiza Agric. Res. Stat. during 2011/12 and 2012/13 growing seasons, to study the influence of different irrigation regimes i.e. irrigation at tillering stage (I1), at tillering and heading stage (I2) and at tillering , heading and grain filling stage (I3) with three methods of sowing i.e. broadcasting, drilling and beds sowing on yield and its components of four wheat cultivars namely Gemmeiza-11, Misr-1, Shandaweel-1 and Sids-12.A significant reductions in grain and straw yields in both seasons was obtained as a result to subjecting wheat plants to drought-stress. Results showed that three irrigations increased significantly number of spikes/m 2 , number of grains/spike, 1000-grain weight, grain weight/spike, biological yield and harvest index except protein content. It could be noticed beds sowing method gave highest yield components. Gemmeiza-11 wheat cultivar surpassed the other tested cultivars concerning with the above mentioned traits, except number of spikes/m 2 and straw yield. While, Misr-1 surpassed in no. of spikes in both seasons and harvest index in the second season, however, Shandaweel-1 produced the highest protein content. A significant interactions between the effect of irrigation (I), sowing methods (M) and wheat cultivars (V) were found in increasing the yield and its components, except between irrigation and sowing methods (I x M) concerning with grain weight/spike (g), grain yield (ardab/fad), straw yield (ton/fad) and biological yield (ton/ fad) in the second season only. Correlation positive and significant relationships between grain yield/fad and all yield components. It could be concluded that to get highest productivity of wheat under middle delta region conditions it must cultivate Gemmeiza-11 cultivar with addition of three irrigations with using the beds sowing method.
In order to investigate the influence of different irrigation regimes i.e. irrigation at tillering stage (I1), at tillering and heading stage (I2) at tillering , heading and grain filling stage (I3) of the available soil moisture depletion with three methods of sowing i.e. broadcasting, drilling and beds sowing on some and characters of growth attributes, relative water content, water use efficiency and drought susceptibility index for four wheat cultivars namely; Gemmeiza-11,Misr-1, Shandaweel-1 and Sids-12. So, two field trials was carried out during 2011/12 and 2012/13 seasons, at El-Gemmeiza Agric. Res. Stat. The results can be summarized as follows: Subjecting wheat plants to drought-stress resulted in a significant reduction in plant height, number of days to heading, number of days to maturity, grain filling period, flag leaf area and relative water content. Water use efficiency and total chlorophyll content tends significantly increased as irrigation regime decreased. Moreover, number of days to heading, number of days to maturity, grain filling period and flag leaf area were insignificant differed due to the tested sowing methods. However, beds sowing method was significantly differed total chlorophyll content, relative water content and water use efficiency. Gemmeiza-11 cultivar surpassed others tested cultivars with respect the abovementioned traits, except number of days to maturity since Shandaweel-1 cultivar was the earliest. Wheat plants grown under severe water deficit were more sensitive to drought. This was clear from drought sensitivity based on drought susceptibility index. Sids-12 and Misr-1 cultivars was proved to be the most drought-tolerant cultivar compared to the other tested ones.
A diallel cross set was carried out at the Experimental Farm of Gemmeiza Agriculture Research Station, Agriculture Research Center, (ARC), Egypt, during the two winter seasons of 2017/2018 and 2018/2019 to assess the variations among six wheat genotypes and their new combinations to estimate heterosis, general and specific combining abilities to determine suitable measurements for drought tolerance in wheat genotypes. Genotypes and the resulted crosses mean squares were found to be either significant or highly significant for all the studied traits under normal and stress environments as well as the combined analysis, except for chlorophyll-a under drought. General combining ability and specific combining ability were found to be significant for all the studied characters under both conditions, except plant height for (SCA) under normal condition, chlorophyll-a for GCA under normal and drought as well as combined analysis and SCA under water-stress condition. The GCA/SCA ratios were found to be greater than unity, suggesting that, additive was much larger and more important than non-additive gene effects in the inheritance of these traits. The two parents Line 1 and Line 3 could be considered as excellent parents in breeding programs aimed to release drought tolerance cultivars. P1, P3, P4, P5 and P6 had the lowest drought susceptibility index value and F1 crosses P1xP2, P1xP3, P1xP4, P1xP5, P2xP6and P3xP5would be classified as drought tolerance due to the least reduction in yield under water stress compared to normal condition, such results might be useful for improving drought tolerance in wheat breeding program.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.