Search Results
Postharvest shelf life of fresh sweet basil (Ocimum basilicum L.) at 5°C is only 3 to 4 d due to development of chilling injury symptoms. Plants chill-hardened at 10°C for 4 h daily (2 h at end of the light period and 2 h at the beginning of the dark period) for 2 d prior to harvest had 3 d extended shelf life at 5°C. Increasing the duration of preharvest chill-hardening did not further improve the shelf life. Plants were chill-hardened at 10°C for 4 h daily for one week at different periods during the day. Four-, 5- and 6-week-old basil were used in each of three consecutive runs. With the 4- and 5-week-old basil, chill-hardening at the beginning of the day extended average shelf life by 1 and 1.5 d at 5°C, respectively. Shelf life was either decreased or not affected by the other periods of preharvest chilling. Postharvest chill-hardening of packaged sweet basil for 1 d at 10°C before transfer to 5°C increased shelf life by 5 d. Postharvest chill-hardening has potential for reducing chilling injury of packaged sweet basil.
Exposure to exogenous ethylene (C2H4) caused corolla abscission of New Guinea impatiens (Impatiens × hawkeri `Sunfire'). Abscission varied with time of exposure and C2H4 concentration. Ethylene at ≥ 1 μl·liter-1 and exposure times of 4 or more hours caused 80% to 100% corolla abscission. Simulated shipping of untreated control plants caused ≈ 65% corolla abscission. Plants pretreated with silver thiosulfate (STS) and (aminooxy)acetic acid (AOA) and subsequently exposed to simulated shipping were not different from one another, and both treatments reduced corolla abscission to ≈ 20% when applied at 1.0 mm. Plants pretreated with STS and exposed to `exogenous C2H4 showed 0% abscission, whereas plants pretreated with AOA showed no reduction in abscission when compared with control plants.
Highbush blueberry (Vaccinium corymbosum L. `Bluecrop') fruit sealed in low-density polyethylene packages were incubated at 0, 5, 10, 15, 20, or 25C until O2 and CO2 levels in the package reached a steady state. A range of steady-state O2 partial pressures (1 to 18 kPa) was created by placing a range of fruit weights within packages having a constant surface area and film thickness. The steady-state O2 partial pressure in packages containing the same weight of fruit decreased as temperature increased, indicating the respiratory rate rose more rapidly (i.e., had a greater sensitivity to temperature) than O2 transmission through the film. Steady-state O2 and CO2 partial pressures were used to calculate rates of O2 uptake. CO2 Production. and the respiratory quotient (RO). The effects of temperature and 02 partial pressure on O2 uptake and CO2 production and the RQ were characte∼zed. The steady-state O, partial pressure at which the fruit began to exhibit anaerobic CO2 production (the RQ breakpoint) increased with increasing temperature, which implies that blueberry fruit can be stored at lower O2 partial pressures when stored at lower temperatures.