Abstract
Induced resistance to bitter rot (Colletotrichum gloeosporioides), brown rot (Monilinia fructicola), green mold (Penicillium digitatum), and Fusarium root rot (Fusarium solani) in 'Golden Delicious' apples, 'Elberta' peaches, 'Dancy' tangerines, and 'Jewel' sweetpotatoes, respectively by treating them with low dose hormetic ultraviolet light-C (UV-C) at the stem end in a stationary position without rotation (STSP) was investigated. This approach was compared with the conventional procedure where produce were rotated four times (CRM), there by exposing the entire surface area to UV-C. Results revealed that when the stem ends of apples, peaches, tangerines, and sweetpotatoes were exposed in a stationary position to dosages of 7.5, 7.5, 1.3, and 3.6 KJm super(-2) of UV-C, respectively induced host resistance to postharvest decay. The percent decay reduction compared to the control was greater than or equal to 80 and greater than or equal to 70% for STSP and CRM methods, respectively. When produce were not rotated and exposed only one or two different sides rotated to UV-C, the percent infection and decay lesion size appeared to increase, compared to STSP and CRM methods. There are two exceptions of the STSP method occurred with greenhouse tomatoes and table grapes. The potential of the STSP method for an on-line conveyor apparatus for commercial application will be discussed.