How to Harvest and Store Corn (Zea mays)

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.