How to harvest and store corn (Zea mays)

Authors: SALAZAR-VIDAL, NANCY MIRIAM - University Of Missouri; DRAVES, MELISSA - University Of Missouri; FITZSIMMONS, SARAH - University Of Missouri; TRAYLOR, ZACHARY - University Of Missouri; Flint Garcia, Sherry

Submitted to: Cold Spring Harbor Protocols
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2025
Publication Date: 6/3/2025
Citation: Salazar-Vidal, N., Draves, M.A., Fitzsimmons, S.L., Traylor, Z.B., Flint Garcia, S.A. 2025. How to harvest and store corn (Zea mays). Cold Spring Harbor Protocols. https://doi.org/10.1101/pdb.prot108639.
DOI: https://doi.org/10.1101/pdb.prot108639

Interpretive Summary: Every year, farmers harvest approximately 15 billion bushels of corn in the United States using large scale harvesting equipment. However growing and harvesting corn (maize) for research is done on a much smaller scale and requires very different processes and equipment. A single variety of research corn is often represented by as few as 15 plants in a field typically planted to hundreds or thousands of varieties. In addition, each of these plants may have been pollinated following different strategies (by different varieties or using different methods), and some ears may not have been manually pollinated and do not need to be harvested. Therefore, the ears from each plant must be harvested and tracked separately. The purpose of this protocol is to provide detailed guidelines for harvesting and long-term storage of corn seeds in a research setting. This protocol will be used by corn researchers, especially those new to the field of corn genetics and breeding, in order to successfully harvest and store their genetic nurseries and experimental materials.

Technical Abstract: Harvest scheduling, seed drying, and good storage practices are essential for maize research to avoid negative impacts on the quality of the seeds and to maximize seed viability. Embryo growth and accumulation of energy reserves in the endosperm are completed ~40 days after pollination, of which the last 10–20 days are devoted to maturation and desiccation. Seed maturity is affected by many factors including temperature, day length, humidity, and soil moisture. Once seeds are mature, they must be harvested. Hand harvesting, which allows for greater control and minimizes ear damage, is primarily used in genetic nurseries and general research because each genotype is represented by a small number of plants. Hand harvesting is also used where there is a mix of manually pollinated and undesired open pollinated ears, and can be a selective harvest depending on the research objectives. However, hand harvesting is more labor-intensive and time-consuming compared to combine harvesting. If harvesting a yield trial, where the purpose is to collect yield data and identify promising genotypes, the use of a combine (not described in this protocol) is critical to consistently capture grain weight, moisture, and test weight for each plot. Following harvest, materials must be dried to the appropriate moisture content before storage. Corn is typically stored using the “active collection” model, with temperatures set between 5°C and 10°C and low relative humidity. This harvest protocol is intended to assist laboratories that are new to maize research and may be modified based on project goals, genetic material, equipment, or available space.