Growth, Yield and Related Physiological Traits of Maize under a Prolonged Irrigation Interval in the Nile Delta of Egypt

Abstract

Water is the primary limiting factor for crop production in Egypt. Two-year field experiments were conducted on Vertisols of the Nile Delta to elucidate the possibility of saving irrigation water during the cultivation of maize (Zea mays L.) by prolonging the irrigation interval in surface furrow irrigation. Maize was grown under a conventional (about 2-week interval: CI) and a prolonged irrigation interval (about 3-week interval: PI). Soil water potential, plant growth, photosynthetic parameters at the early grain-filling stage of maize plant, and grain yield were investigated. The results showed that the PI markedly affected the photosynthetic rate via stomatal closure, especially at midday, and reduced dry matter production by 49% at the early grain-filling stage. However, no significant differences were detected for the final grain yield in both years. Water use efficiency (WUE) based on dry matter production at the early grain-filling stage was higher under CI, while WUE based on grain yield was higher under PI. The absence of differences in yield under different irrigation intervals was ascribed to the availability of water within the deeper soil profile. The results suggested that the water-saving irrigation method enabled to improve the final WUE and to maintain the maize grain yield. The prolonged irrigation interval could save 8-11% of water use in the Nile Delta region, covered by heavy clayey soil. Our study also contributed to the understanding of the response of maize plant leaf photosynthesis to water-deficit.