Egypt is generally known for its arid desert climate. Western and Eastern deserts comprise an area of around 68 and 22% of Egypt’s total area, correspondingly. Due to the insignificant amount of precipitation, the reclaimed desert areas are entirely dependent on irrigation with groundwater, which is primarily extracted from the Nubian Sandstone and carbonate aquifers, providing an irregular water supply. Therefore, Water deficit is the major challenge facing agriculture in these areas that are classified as arid and hyper-arid regions with their hot and rainless climate. In such adverse conditions, the expansion of cultivated land is not considered a feasible option for agricultural intensification, as an alternative, the utilization of high yielding, stress-tolerant crops would be more feasible. Therefore, there is a dare need to expand the production of crops and varieties known for their tolerance to adverse environmental conditions, especially drought, for feeding the continuously growing population.
The main summer staple crops in Egypt are maize and rice with their production restricted to the delta region due to their high-water requirements and need for special soil and climate.
Dahlbert et al. (2004) claimed that millet flour can be a substitute for 10-20% of wheat flour in baking different types of bread. Pearl millet is an important source of nutrition for populations with substandard economic conditions that inhibit different parts of the world, especially in Asia and Africa. Jukanti et al. (2016) stated that pearl millet is tolerant to drought and high temperatures driven by its high tillering capacity and deep root system that help the crop to withstand adverse conditions that may cause yield reductions or crop failure in other summer crops. Moreover, pearl millet produces a rational amount of yield when grown in soils with low fertility. Thus, it provides staple food particularly for rural inhabitants living in areas subject to severe environments and unfavorable farming contexts mainly because of drought and poor soils. Plant density greatly influence grain yield and yield components of pearl millet as it determines the inter-and intra-plant competition for groundwater and soil nutrients along the growing season. Currently, a research published in the Asia Journal of Plant Sciences that was presented by the Shaalan et al. (2021) evaluate the grain yield and some agronomic characteristics of four newly introduced and one local pearl millet genotypes under three plant densities when grown in the arid conditions of the North West Coast of Egypt. The results indicated that the low and intermediate plant densities supported the production of a higher number of tillers and panicles with heavier panicles and grains, which were clearly reflected on the higher final grain yields with the intermediate plant density being superior to the low. So, they concluded that the shorter plants produced with decreased plant densities are more resistant to lodging that ultimately reduces the risk of crop failure.