The impacts of climatic changes on the yield and water use efficiency of maize grown under different sowing dates and two irrigation schemes in arid climate

Upper Egypt is characterized by high temperatures in summer and low temperatures in winter, which has a significant impact on the dates of planting maize in this region. The productivity of the maize crop as well as the efficiency of the use of water can be severely affected by planting dates and drought. Consequently, the optimum irrigation level and planting date must be determined based on local conditions. Two irrigation schemes were used: (1) control (full irrigation water applied), (2) 70% of irrigation water. Field experiments were conducted at the water studies and research complex station, National Water Research Center in Toshka to evaluate two irrigation levels (full irrigation water applied and 70% of irrigation water requirements) under five planting dates (early seeding (mid-February and March), normal (mid- June) and late planting (mid- August and September) in 2019 and 2020) to determine the optimum planting date and irrigation level. Early SD has increased the days between seeding and plant emergence. Late SD reduced the number of days until the plant matured and had higher grain yields and water use efficiency (WUE). The planting date in September under the irrigation level of 70% achieved the best productivity and the best water use efficiency, where the productivity was 7.01 Mg ha −1 and the water use efficiency was 0.72 kg/m 3 The data confirm the general perception of farmers that the September sowing date under 70% irrigation levels is the best within the experimentation area.