Low Humidity, Warm AIr Storage Effective for Medium-Term Storage of Sweet Onions

Onions of the variety Granex 33 were placed in low humidity, warm air storage for a minimum of 15 weeks andthen examined for weight loss, pungency, soluble solids, and disease presence. They were compared with onions held in coldand CA storage. Temperature and relative humidity of the air in the low humidity, warm air storage established levels asgenerated by a heat-pump-dehumidifier with means 30.C to 34.C and 29% to 36% R.H. over years, there being a 0.2.C to0.6.C and 0.1% to 0.6% R.H. differential between intake and exhaust conditions. Low humidity, warm air storage provedsuitable for mid-term storage of healthy onions or those onions with shallow surface diseases whose disease developmentcould be halted. Onions containing hidden internal diseases were exasperated by the warm circulating air, causing furtherdisease development.