ARTIFICIALLY CURING SWEET ONIONS

An index of cure was developed and used to evaluate the extent of curing of sweet onion as influenced by different treatment effects of the maturity of onions at harvest, the duration of cure and the depth of onions in the stack during curing. In order to obtain a complete cure, the required duration of cure varied most of all with harvest maturity. For onions harvested at an optimal maturity, 48 h was necessary to obtain a good level of curing, A small benefit was observed when curing was extended to 72 h. For onions harvested after the optimal maturity, 24 h was sufficient. However, onions harvested before the optimal maturity were not fully cured after 72 h. Depth of onios influenced curing because the drying front moved through the stack in the direction of the airflow and curing was not complete for the whole stack of onions until the drying front had completely moved through the onions. A similar value of curing index may be procured from different combinations of harvest maturity, depth of cure and period of cure