Currently, most sweet corn in the state of Georgia is produced and shipped wholesale for fresh market consumption. The majority of producers in the state aim for a Fourth of July harvest, and shipper sweet corn is a significant source of income for Georgia vegetable growers. Plant population density is a critical factor for achieving optimal yield while balancing resource inputs, and the commercial standard for sweet corn in the state is 60,000 to 74,000 plants ‧ ha-1. While recent research in the midwestern U.S. suggests that planting densities for processing sweet corn can be pushed above previously recommended ranges to optimize profit, little work has been done in current years concerning fresh market shipper sweet corn in the southeastern region of the country, which differs drastically in soil type and seasonal weather patterns. Therefore, the objective of this study is to re-evaluate current state guidelines for plant population density to optimize marketable yields by manipulating inter- and intra-row plant spacing. To do this, sweet corn (cv. ‘Obsession’) was sown directly to the field in the spring season of 2023 at a rate of 43,000 to 107,000 plants ‧ ha-1, which was achieved with sowing patterns in either two or three rows per bed top (91 cm or 46 cm apart, resp.), and five within-row spacings ranging from 15 cm to 25 cm at 2.5 cm increments. The field was managed according to the University of Georgia's irrigation, fertilizer, insect, and disease management guidelines. At harvest, the number, size, and tip fill of ears were collected, with marketable ears categorized based on USDA Fancy grading standards for a minimum length of 15 cm and unfilled kernels at tips covering less than one-fourth cob length. A significant increase in marketable yield was associated with the number of rows but not within-row spacing, with an average increase of 24% in three-row treatments (p < 0.05). There was not a significant difference in unmarketable yield between row treatments. Preliminary results indicate that plant population density for shipper sweet corn in Georgia can be increased by adding a third row while maintaining fresh market quality.
