Wheat flour products are the main dietary component of the Qinghai–Tibetan Plateau (QTP) population in China.  However, the high altitude restricts the local wheat quality and quantity, and the applied nitrogen rate is higher than the optimal rate for wheat planting.  In this study, we considered whether reducing the amount of nitrogen fertilizer and introducing the superior varieties from the North China Plain (NCP) are viable ways to increase the wheat quality and quantity in the QTP.  Three and four winter wheat cultivars from QTP and NCP, respectively, were planted in Lhasa at an altitude of 3 647 m with reduced topdressing nitrogen application at the jointing stage.  The wheat from NCP exhibited higher grain hardness index and test weight, and better flour and dough quality.  Reducing the topdressing nitrogen fertilizer from 135 to 75 kg N ha⁻¹ at the jointing stage (with the same basal fertilization of 105 kg N ha⁻¹) did not significantly (P<0.05) affect the grain yield, grain quality, flour quality or dough quality in any of the cultivars.  In summary, introducing high-quality winter wheat varieties from the NCP to the Lhasa plateau is a viable way to enhance the wheat supply and quality in the QTP.  Reducing a certain amount of the nitrogen fertilizer is an economic and feasible approach for the QTP region.

Wheat was the first crop grown in Egypt, and it remains highly important.  Egypt is the largest wheat importer in the world and consumes an extensive amount of bread.  It is imperative for wheat scientists to decrease the large gap between production and consumption.  Wheat yields in Egypt increased 5.8-fold (6.7 billion kg) between 1961 and 2017 due to variety improvement and the use of better planting methods such as the raised bed method, ideal sowing date, surge flow irrigation and farm irrigation systems, laser levelling, fertilizers, and intercropping with raised beds.  In this paper, the development of wheat production techniques and variety evolution over more than five decades in Egypt have been analyzed.  In particular, we have focused on the technologies, cultural practices and causes for per unit area yield increase.  The main purpose was to study the issues that have arisen during wheat production and to make recommendations for smart agricultural practices.  In 1981, the yield was 3 300 kg ha^–1 and through the improvement of varieties, expansion of agricultural land and the adoption of modern agricultural techniques yield reached 6 500 kg ha^–1 by 2017.  The production growth rate was 4.1% annually, and the total grain yield increased 4.3-fold, from 1.9 billion kg in 1981 to about 8.1 billion kg in 2017.  The use of new improved varieties, new cultivation techniques, and modern irrigation techniques contributed to 97.0% of the increase in yield per unit area and 1.5% of the increase in yield was due to planting area expansion.  Therefore, the increase in total yield mainly depended on the increase in yield per unit area.  Wheat production in Egypt has been improved through the development of breeding and cultivation techniques.  The use of these new techniques, the popularization of new high-quality seed varieties, and the use of the raised bed method instead of the old method of planting in basins have made the largest contributions to increased yield.  In the future, wheat yield could be further increased by using the tridimensional uniform sowing mode and the development of wheat varieties that are resistant to rusts, deficit irrigation, and abiotic stress, that are highly adaptable to mechanized operation and have high yields.  Based on our analysis, we propose the main technical  requirements and measures to increase wheat yield in Egypt in the near future.

Improving radiation use efficiency (RUE) of the canopy is necessary to increase wheat (Triticum aestivum) production.  Tridimensional uniform sowing (U) technology has previously been used to construct a uniformly distributed population structure that increases RUE.  In this study, we used tridimensional uniform sowing to create a wheat canopy within which light was spread evenly to increase RUE.  This study was done during 2014–2016 in the Shunyi District, Beijing, China.  The soil type was sandy loam.  Wheat was grown in two sowing patterns: (1) tridimensional uniform sowing (U); (2) conventional drilling (D).  Four planting densities were used: 1.8, 2.7, 3.6, and 4.5 million plants ha^–1.  Several indices were measured to compare the wheat canopies: photosynthetic active radiation intercepted by the canopy (IPAR), leaf area index (LAI), leaf mass per unit area (LMA), canopy extinction coefficient (K), and RUE.  In two sowing patterns, the K values decreased with increasing planting density, but the K values of U were lower than that of D.  LMA and IPAR were higher for U than for D, whereas LAI was nearly the same for both sowing patterns.  IPAR and LAI increased with increasing density under the same sowing pattern.  However, the difference in IPAR and LAI between the 3.6 and 4.5 million plants ha^–1 treatments was not significant for both sowing patterns.  Therefore, LAI within the same planting density was not affected by sowing pattern.  RUE was the largest for the U mode with a planting density of 3.6 million plants ha^–1 treatment.  For the D sowing pattern, the lowest planting density (1.8 million plants ha^–1) resulted in the highest yield.  Light radiation interception was minimal for the D mode with a planting density of 1.8 million plants ha^–1 treatment, but the highest RUE and highest yield were observed under this condition.  For the U sowing pattern, IPAR increased with increasing planting density, but yield and RUE were the highest with a planting density of 3.6 million plants ha^–1.  These results indicated that the optimal planting density for improving the canopy light environment differed between the sowing patterns.  The effect of sowing pattern×planting density interaction on grain yield, yield components, RUE, IPAR, and LMA was significant (P<0.05).  Correlation analysis indicated that there is a positive significant correlation between grain yield and RUE (r=0.880, P<0.01), LMA (r=0.613, P<0.05), and spike number (r=0.624, P<0.05).  These results demonstrated that the tridimensional uniform sowing technique, particularly at a planting density of 3.6 million plants ha^–1, can effectively increase light interception and utilization and unit leaf area.  This leads to the production of more photosynthetic products that in turn lead to significantly increased spike number (P<0.05), kernel number, grain weight, and an overall increase in yield.