Rhizomes of Oxalis adenophylla Gillies and bulbs of Ipheion uniflorum Raf. were planted and wet- or dry-stored at 5 °C for 0, 6, 10, 14, or 18 weeks, before being placed in a greenhouse. Regardless of moisture regime, foliage emergence and time to flower decreased for both species with increasing duration of cooling. Wet-stored bulbs/rhizomes within a cooling treatment required less time to foliage and flower emergence when compared with the corresponding dry-storage period. About 10 weeks of 5 °C was optimum for both species.
Allan M. Armitage, Linda Copeland, Paula Gross, and Meg Green
Y.J. Yang and K.A. Lee
148 POSTER SESSION 17 (Abstr. 120–133) Postharvest Physiology/Storage/Food Science Wednesday, 26 July, 1:00–2:00 p.m.
Rod Jones and John Faragher
Five members of the Proteaceae and 13 Australian native cut flower cultivars were stored for 35 days under standard conditions at 1C to assess their ability to withstand long-term storage and transport. Protea cynaroides L., Leucadendron `Silvan Red', Leucospermum `Firewheel', Thryptomene calycina (Lindl.) Stapf., Telopea speciosissima R. Br., and Verticordia grandtiflora Endl. retained a vase life of at least 7 days after 21 days of storage. Leucospermum cordifolium Salisb. ex Knight, Protea neriifoli R. Br., Chamelaucium uncinatum `Alba', C. uncinatum `Purple Pride', Verticordia monadelpha Turcz., Verticordia plumosa (Desf.) Druce, and Verticordia nitens (Lindl.) Schau. suffered a decline in vase life ranging from 31% to 100% after 14 to 21 days of storage. Species of Verticordia and Chamelaucium were particularly susceptible to fungal infection. Anigozanthos pulcherrimus Hook. and the Anigozanthos cultivars Ruby Delight, Bush Harmony, Bush Haze, and Gold Fever all showed a significant reduction in vase life after 14 days of storage compared with unstored controls.
Kathryn L. McDavid, David L. Sanford, and Robert D. Berghage
on the effects of storage or germination temperature on germination rates of stonecrop species. Bonde (1965) showed that lanceleaf sedum ( Sedum lanceolatum ) seed germinated at 92.5% using growth chambers set at 18 °C. Widow’s cross sedum ( Sedum
Francisco Artés, Angel J. Escriche, and Jose G. Marin
Several intermittent 13C warming treatments were applied to `Primofiori' lemons (Citrus limon Burn) stored at 2 or SC. Fruit stored at 13C were treated with 10%, 2090, or 30% CO2 for 24 hours at weekly intervals. Reduction in decay and physiological disorders was best with two cycles of 2 weeks at 2C and 2 weeks at 13C and relative humidity >95 %. Under this storage condition, soluble solids concentration, pH, titratable acidity, and reducing sugars did not change relative to values at harvest, but the concentration of ascorbic acid increased and that of nonreducing sugars decreased in relation to harvest values. Carbon dioxide treatments did not prevent the development of alternaria (Alternaria citri Ell. & Pierce) rot and red blotch disorder, but effectively prevented the development of membranosis, rind pitting, and oleocellosis.
Andres A. Reyes
The virulence of Mucor mucedo (L.) Fr. (the cause of mucor rot) and Botrytis cinerea Pers. (gray mold) on vegetables stored at 13C for 7 days or 1C for 70 days varied with the host and controlled atmosphere (CA). M. mucedo was severely pathogenic at 13C to cucumber (Cucumis sativus L.), eggplant (Solarium melongena L. var. esculentum Nees), pepper (Capsicum annum L.), and tomato (Lycopersicon esculentum Mill.), but not to bean (Phaseolus vulgaris L.). The fungus did not infect carrot (Daucus carota L. var. sativa DC.), celery (Apium graveolens L. var. dulce DC.), onion (Allium cepa L.), or parsnip (Pastinaca sativa L.) at 1C. B. cinerea was virulent on all of these crops at 13 or 1C. The severity of mucor rot and gray mold on eggplant stored at 13C for 14 days was suppressed most in a CA of 7.5% CO + 1.5% O2 and least in 1.5% 02, in comparison with the air control. Similarly, the growth and sporulation of each pathogen on eggplant-extract agar maintained at 13C for 4 or 14 days were suppressed most in 7.5% CO + 1.5% O2; suppression was least in 1.5% O2. The suppression of diseases on eggplant was highly correlated with the suppression of mycelial growth and sporulation of pathogens on agar.
Lihua Fan, Jun Song, Charles F. Forney, and Michael A. Jordan
Ethanol concentration and chlorophyll fluorescence (CF) were measured as signs of heat stress in apple fruit [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.]. `McIntosh', `Cortland', `Jonagold', and `Northern Spy' apples were placed in trays and exposed to 46 °C for 0, 4, 8, or 12 hours. Following treatments, fruit were stored in air at 0 °C and evaluated after 0, 1, 2, or 3 months. Ethanol and ethylene production, CF, peel and flesh browning, firmness, skin color, soluble solids, and titratable acidity were measured. Increases in ethanol were apparent immediately following 12-hour heat treatments as well as after 3 months. After 3 months, ethanol concentrations were 16-, 52-, 6-, and 60-fold higher in `McIntosh', `Cortland', `Jonagold', and `Northern Spy' apples than in controls, respectively. The concentrations of ethanol accumulated reflected the degree of heat-induced fruit injury. Heat treatments reduced ethylene production relative to control values. After 3 months of storage ethylene production of fruit exposed to 46 °C for 12 h was <0.48 μmol·kg-1·h-1 compared to >4.3 μmol·kg-1·h-1 for controls. Heat treatments also reduced CF which was expressed as Fv/Fm, where Fv is the difference between the maximal and the minimal fluorescence (Fm - Fo), and Fm is the maximal fluorescence. After 3 months storage at 0 °C, Fv/Fm was ≈0.2 in fruit held at 46 °C for 12 hours compared with 0.5-0.6 for control fruit. Exposure to 46 °C for 12 hours caused severe peel and flesh browning in all cultivars. Severity of peel and flesh browning increased with increasing duration of heat treatment and subsequent storage at 0 °C. `Northern Spy' apple fruit were most susceptible to heat stress based on the degree of flesh browning. Heat treatments of 8 and 12 hours reduced firmness of `McIntosh', `Cortland', and `Northern Spy', but not `Jonagold' apples. Hue angle of the green side of fruit was also reduced in `Cortland', Jonagold' and `Northern Spy' apples receiving the 8- and 12-hour treatments. Heat treatments caused a decrease in fruit tiratable acidity, but had no effect on soluble solids content. The increase in ethanol production and decrease in CF correlated with heat-induced injury, and were apparent before browning was visually apparent. Ethanol and CF have the potential to be used to nondestructively predict the severity of injury that develops during storage.
D. H. Scott and A. D. Draper
In a germination test with strawberry seed of different ages stored at 40°F, 23-year-old seed germinated as well as 1-year-old seed. Germination was relatively high for all of the seed lots, despite differences in age.
Norman E. Looney
Ripening of ‘Bartlett’ pears at 20°C was assessed in samples harvested weekly beginning 4 weeks prior to commercial harvest maturity. Ripening was promoted by delaying harvest, by 1- and 2-week periods of storage at 4.4°C, or both. Early summer treatments with 750 and 7500 ppm succinic acid-2,2-dimethylhydrazide (SADH) delayed ripening but this effect was counteracted by both delayed harvest and postharvest storage at 4.4°C. It is concluded that SADH delays ripening by influencing an endogenous mechanism for controlling ripening in pears.
E. Chalutz, G. Felsenstein, and J. Waks
An inexpensive method for accurate control and measurement of fresh air introduction into experimental storage rooms is described.