TOMATO IRREGULAR-RIPENING SYMPTOM DEVELOPMENT AND RIPENING OF SILVERLEAF WHITEFLY-INFESTED DWARF CHERRY TOMATOES

Silverleaf whitefly (SLW) (Bemisia argentifolii Bellows and Perring) f eeding was associated with development of tomato irregular ripening (T IR) symptoms, 'Micro-Tom', 'Florida Basket', 'Florida Lanai', and 'Flo rida Petite' dwarf cherry tomatoes (Lycopersicon esculentum Mill.) wer e infested with adult SLW to observe oviposition preference, plant tol erance, and TIR symptom development in two experiments. There was no o viposition preference among the cultivars in either of the trials. TIR fruit symptoms were expressed as longitudinal red streaks with yellow , green, pink, or red blotches externally and white tissue internally. External TIR symptoms at the pink stage of ripening ranged from 32% ( 'Micro-Tom') to 82% ('Florida Basket') in Expt, 1 and 44% (Micro-Tom') to 93% ('Florida Petite') in Expt. 2. In Expt. 1, external TIR sympto ms disappeared from 18% ('Florida Lanai') to 37% ('Micro-Tom') and, in Expt. 2, 16% ('Micro-Tom') to 39% ('Florida Basket') of the fruit dur ing ripening, SLW-infested plants exhibited 82% ('Florida Lanai') to 9 9% ('Florida Basket') and 76% (Micro-Tom') to 90% ('Florida Petite') o f fruit with internal white tissue regardless of external symptoms in Expts. 1 and 2, respectively. Tomatoes with severe TIR symptoms rarely ripened to full red. Postharvest characteristics of ripening SLW-infe sted and control fruit were evaluated (Expts. 3 and 4), Generally, the SLW-infested fruit were lighter in color than the control fruit. The control fruit developed normal red color while the SLW-infested fruit developed a blotchy, streaky color that was overall more of an orange- red. SLW-infested fruit were firmer than the control fruit in both exp eriments. Ethylene production was higher in SLW-infested fruit. While the total soluble solids contents were not significantly different bet ween the treatments, the SLW-infested fruit were more acidic than the control fruit. Each cultivar was susceptible to oviposition by SLW and induction of TIR symptoms. However, TIR symptom expression differed a mong the cultivars. Despite higher ethylene levels, the ripening proce ss in the SLW-infested fruit appeared slower or may have been inhibite d by factors induced by the SLW compared with the control fruit, which ripened normally.