Global demand for corn (Zea mays L.) is increasing and it remains one of the most consumed crops by both humans and animals due to its high calorie content. However, corn grain quality research is sparse and often focused only on a few selected influencing factors. Therefore, two side‐by‐side studies (Addition and Deletion) were conducted in 2020 and 2021 in Mississippi, assessing the grain composition including protein, starch, oil, and moisture of corn under several management practices. A randomized complete block design was implemented in both experiments involving a complete factorial of three factors including two plant populations (32 and 40K seed acre−1), two‐row configurations (single and twin), and six combinations of nutrients plus fungicide application (NF). The trials differed based on the manner of NF applications. In trial termed Addition, all NF treatments were added incrementally, whereas in the Deletion trial, they were withheld in a stepwise manner. Conditional inference tree (CIT) analysis was conducted to examine interaction effects among the three factors over site‐years. Corn protein content ranged between 8.2 and 9.8% across all years and locations. All three factors and certain interactions significantly influenced both protein and starch content. Specifically, single row, 40K seeds acre−1, and higher rates of N resulted in higher protein content. Contrarily, the starch content was positively influenced by twin row, 32K seeds acre−1 and only N application. Single row configuration resulted in higher oil than twin rows. This study determined that different management factors have the potential to positively influence protein, starch, and oil. These management strategies could extend farmers profitability and provide superior products for industrial purposes with additional implications for livestock feed supplements.This article is protected by copyright. All rights reserved