Response of Yield Formation of Maize Hybrids to Different Planting Densities

Abstract

Crop density is a means that controls grain yield establishment. This study was focused on evaluating the effect of four crop densities (CD1—50,125 plants ha−1, CD2—59,523 plants ha−1, CD3—69,686 plants ha−1, and CD4—79,365 plants ha−1) on yield components, grain yield, sustainable yield index (SYI), and rain use efficiency (RUE) of the maize hybrids ZP 500, NS 5010, and AS 534 during 2016–2018. In 2017, due to unfavorable meteorological conditions, ear length, number of grains per ear, grain weight per ear, 1000-grain weight, grain yield, SYI, and RUE were low compared to 2016 and 2018. The hybrid NS 5010 had the lowest ear length, number of grains per ear, grain weight per ear, 1000-grain weight, grain yield, and SYI. Increasing crop density significantly decreased yield components and increased grain yield, SYI, and RUE. The lowest ear length was recorded in treatments CD3 and CD4, the lowest number of grains per ear, grain weight per ear, and 1000-grain weight in treatment CD4. However, the highest grain yield, SYI, and RUE were recorded in the CD4 treatment because the number of plants per unit area is an essential determinant of the final grain yield.