The Effect of Maleic Hydrazide Salts on Quality and Bulb Tissue Residues of Stored ‘Yellow Sweet Spanish’ Onions1

Abstract

Abstract Diethanolamine and potassium salts of maleic hydrazide (MH) were applied to plants of ‘Yellow Sweet Spanish’ onion (Allium cepa L.) exhibiting maturity ratings of 0, 25, 50, and 100% green tops down. The K formulation of MH was equal to the diethanolamine formulation in sprout control of onions in storage. Lower application rates resulted in lower bulb residues; however, there were no consistent differences in bulb residues among the maturity treatments. Concentrations of MH were lowest in mature outer scales. Maleic hydrazide applications significantly reduced sprouting during storage, had no effect on the percentage of bulbs with storage rot, and reduced respiration rates and weight loss of bulbs stored at 10°C, but had no effect on respiration rate and only slightly reduced weight loss of bulbs stored at 4°. Root growth occurred on nontreated bulbs at both 4 and 10°, while root development was inhibited in MH-treated onions.