Although leading producers in South Africa achieve record yields exceeding local averages by approximately 10 tons per hectare, many farmers do not utilize the full potential of their seeds. Agronomist Nico Barnard from Pannar Seed explains how this significant yield gap can be overcome by protecting crop potential through timely and targeted operations.
The yield gap is defined as the difference between the full genetic potential of the crop and what is actually harvested. Every season, farmers start with maximum potential, but unaddressed limitations constantly reduce this prospect.
Achieving higher productivity depends on optimizing existing management practices, including soil condition and field operations, rather than simply trying to solve agronomic problems by increasing costs.
Higher resource expenditure does not automatically guarantee a greater harvest. Adding more fertilizer or increasing planting density often does not address underlying limitations such as soil compaction or low root volume.
Barnard notes: 'Farmers must optimize what they already have before adding extra resources. For example, if poor establishment is caused by soil compaction, applying more fertilizer to the field may not solve the core problem, as plant roots may still struggle to access water and nutrients.'
Instead of relying on more intensive application, he advises that the true value lies in precise placement of resources, timely weed control, and eliminating physical barriers in the soil so that root systems can effectively absorb applied nutrients.
Barnard asserts that corn yield develops in stages based on four key factors: plant density, ear count, kernel count per ear, and final grain mass. The main characteristics of the ear are established early—the number of rows is determined around the V5 growth stage, and the number of kernels per row at the V12 stage, long before the ears become visible in the field.
When environmental stresses or nutrient deficiencies occur during grain development, the plant limits its energy load through kernel abortion. Since approximately one-third of the total dry matter of the crop accumulates in the last 30 days before physiological maturity, late-season management remains equally important.
Maintaining healthy leaf surface against diseases and ensuring active photosynthesis during grain filling protects the final grain mass, guaranteeing a strong completion of the crop cycle.
Achieving an even, uniform planting from the start is mandatory, as losses incurred in the early stages can never be compensated for later in the life cycle. Barnard warns: 'Every missing, weak, or late germinating plant can reduce the crop's ability to reach its potential.' He adds that good establishment starts with quality seed but also depends on creating favorable and uniform conditions for germination and emergence.
Narrowing the yield gap begins with identifying the specific factors limiting production on individual fields. Producers can consistently protect yield potential and ensure higher profits by making targeted, phased operational adjustments instead of trying to change everything at once.
