N. E. Cheatham
Natural curing may be beneficial if onions are grown in a climate hot and dry enough for them to be cured outside. In natural curing, onions are typically windrowed, topped, and left to dry in the field in bags or crates for a period of at least 5 days. During this time, precipitation could disrupt the curing process. If weather does not permit windrowing, other drying methods may be necessary. It has been noted that for optimal curing, the use of bulk pallets or wooden crates should be considered (Vaughan, Cropsey, & Hoffman, 1964). It should also be noted that if curing in crates or pallets is not possible, curing onions in burlap bags is suggested (Vaughan, Cropsey, & Hoffman, 1964). An onion has been correctly cured when the neck is dry and shrunken (Matson, Mansour, & Richardson, 1985).
Other natural curing methods minimize handling by allowing crops to cure in place. In the cure-in-place method, water supply to onions is cut 1 to 2 weeks before lifting, working best in areas with dry, warm harvesting seasons. Once fields have been dried, onions can be undercut (removal of roots) by a machine, then lifted, topped, and loaded in a one step process for immediate bagging or storing. This minimal handling process maximizes efficiency by reducing costs, energy usage, and the amount of harvesting processes.