Maize Performance under Different Levels of Plant Population Density and Time of Defoliation

O. Almahdi, Idris; E.A. Khalil, Hassan; Nawar, Ali I.

doi:10.21608/asejaiqjsae.2025.436176

Maize Performance under Different Levels of Plant Population Density and Time of Defoliation

Document Type : Original Article

Authors

¹ Crop Science Dept., Benghazi University, Libya.

² Crop Intensification Dept., Field Crops Research Institute, Agricultural Research Center.

10.21608/asejaiqjsae.2025.436176

Abstract

Two field experiments were carried out, in the summer seasons of 2021 and 2022 at Agriculture Research Station, Alexandria University, Alexandria, Egypt, to study the response of some growth and productivity traits of maize (Giza 168 cultivar) to three plant densities (46.6, 57.0 and 71.4 thousand plants/ ha) and four defoliation treatments of D₀= no defoliation besides D₁, D₂ and D₃ defoliation times applied, at 60, 75 and 90 days after sowing (DAS). Forage production by defoliation was found to be closely related to time of defoliation and plant density, where the maximum leaves yield was obtained from the highest plant density and defoliation at 90 days (3.66 and 3.60 t/ ha in 2021 and 2022 seasons, respectively), whereas the respective lowest leaves yield of 2.53 and 2.70 t/ ha, were obtained from the lowest plant density and defoliation at 60 DAS. Grain yield production was found to be a function for defoliation time and plant density, where the lowest grain yield was obtained with the lowest plant density and defoliation at 60 DAS (3.92 and 3.87 t/ ha in 2021 and 2022 seasons, respectively), while the respective highest grain yield was produced by no defoliation and highest plant density (5.72 and 5.54 t/ ha) and it was statistically similar to defoliation at 90 DAS for the same plant density. Quadratic response indicated that the optimal plant density for grain yield was lower than the maximum applied density. However the highest grain yield was obtained with the maximum plant density. That implies the necessity to determine the increase of grain yield above the optimal density in relation to economic return per unit area.
In conclusion, both proper time of defoliated leaves at maximum plant density, without significant reduction in grain yield, encourages maize cultivation as a dual purpose crop (food for humans and fodder for animals).

Keywords