tie-up Removal of some of the leaves (typically at least half or more) and cutting back and tying up the remainder are standard, yet nonetheless, controversial industry practices when transplanting palms. They purportedly reduce water loss and keep the
Donald R. Hodel, A. James Downer, and Dennis R. Pittenger
Harvey E. Arjona, Frank B. Matta, and James O. Garner Jr.
Vine-ripened yellow passion fruit (Passiflora edulis f. flavicarpa Deg.) were placed in styrofoam trays and wrapped with VF-60 plastic film and stored for 15 and 30 days. Wrapping prevented fruit weight loss while maintaining external appearance. Storage time contributed to quality loss of external appearance. Wrapping maintained fruit glucose and fructose content at 43 and 40 mg·ml-1 up to 15 days, respectively, and did not influence juice pH. Initial sucrose content of wrapped fruit declined 62% after 15 days in storage. Plastic film did not effectively modify O2 or CO2.
Kate M. Maguire, Nigel H. Banks, Alexander Lang, and Ian L. Gordon
Research quantified contributions to total variation in water vapor permeance from sources such as cultivar and harvest date in `Braeburn', `Pacific Rose', `Granny Smith', and `Cripps Pink' apples [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.]. In a study on `Braeburn' fruit from eight orchards in Central Otago, New Zealand, >50% of the total variation in permeance was associated with harvest date. This variation was the result of a large increase in water vapor permeance from 16.6 to 30.2 (se = 0.88, df = 192) nmol·s-1·m-2·Pa-1 over the 8 week experimental harvest period. Fruit to fruit differences accounted for 22% of total variation in permeance. Interaction between harvest date and orchard effects explained 7% of the total variation, indicating that fruit from the different orchards responded in differing ways to advancing harvest date. Tree effects accounted for only 1% of the total variation. Weight loss from respiration [at 20 °C and ≈60% relative humidity (RH)] comprised 3.04±0.11% of total weight loss, averaged across all harvest dates. In a second study of fruit of four apple cultivars, almost 30% of the total variation in water vapor permeance was associated with cultivar differences. Mean water vapor permeance for `Braeburn', `Pacific Rose', `Granny Smith', and `Cripps Pink' fruit was 44, 35, 17, and 20 (se = 4.3, df = 300) nmol·s-1·m-2·Pa-1 respectively. Over 20% of the total variation was associated with harvest date and arose from a large increase in water vapor permeance from 21 nmol·s-1·m-2·Pa-1 at first harvest to 46 nmol·s-1·m-2·Pa-1 (se = 5.3, df = 200) at final harvest, 10 weeks later, on average across all four cultivars. There was large fruit to fruit variation in water vapor permeance accounting for 25% of the total variation in permeance values. Tree effects only accounted for 4% of the total variation. Water vapor permeance in `Pacific Rose'` and `Braeburn' increased substantially with later harvest but values remained relatively constant for `Granny Smith' and `Cripps Pink'. A simple mathematical model was developed to predict weight loss from `Braeburn' fruit. Based on these findings, it appears worthwhile to increase the stringency of measures to control weight loss in `Braeburn' and `Pacific Rose'` apples, particularly those harvested late in the season.
L. G. Albrigo
Antitranspirant sprays of 5 film-forming materials were compared on mature Citrus sinensis (L.) Osbeck cv. Valencia trees for film persistence and reduction of fruit weight loss after harvest. These materials were also sprayed on young ‘Pineapple’ (C. sinensis) or ‘Valencia’ orange trees growing in 7.6 liter containers on which weight loss was subsequently measured for 48-hour periods after watering. Spray solutions of equal or known film-forming ingredients (solids content) of 1 to 4% (weight/weight) were applied and compared. Plantgard film did not significantly increase the leaf epicuticular coating nor did it reduce fruit weight loss or young tree water use. Mobileaf, Vapor Gard, Nu-Film-17, and Wilt Pruf NCF did result in heavier leaf coatings and less fruit weight loss than the controls. Mobileaf and Vapor Gard reduced potted tree water use. Some loss of effectiveness and coating thickness occurred 5 months after application, but only a small nonsignificant change in effectiveness occurred during the first 2 months after application. Mobileaf and Vapor Gard appeared to give the best antitranspirant protection for the initial 2 months and Vapor Gard for 5 months.
Robert E. Paull
Rating scales and their descriptions are described for spadix condition, spathe discoloration, and gloss for anthurium inflorescence.
Preeti Sood, Chris Ference, Jan Narciso, and Ed Etxeberria
potential adverse effects during storage. The pinhole depressions applied after washing and waxing disrupt the natural cuticular barrier and the protective commercial wax cover, seemingly creating open cavities that would allow for increased water loss and
Eliahou Cohen, Yavin Shalom, and Ida Rosenberger
Britex and Zivdar, water-based polyethylene waxes, were applied in commercial and experimental formulations as spray coating, a single dip, or double dips on `Murcott' tangerine (Citrus reticulate Blanco) fruits. Postharvest waxing of `Murcott' tangerine reduced weight loss but affected the sensory characteristics of the fruit. Charges in fruit weight loss and juice composition occurred in the waxed fruits after 4 weeks of storage at 5C plus 1 week of simulated retail handling at 17C. Changes in internal fruit atmosphere were related to fruit flavor quality.
Michael R. Evans, Andrew K. Koeser, Guihong Bi, Susmitha Nambuthiri, Robert Geneve, Sarah Taylor Lovell, and J. Ryan Stewart
been to compare irrigation requirements to those of traditional plastic containers. Evans and Karcher (2004) found that when comparing peat, feather fiber, and plastic containers, the peat containers had the highest rate of water loss through the
Sissel Torre, Tove Fjeld, Hans Ragnar Gislerød, and Roar Moe
Single node cuttings with one mature leaf were taken from Rosa ×hybrida `Baroness' and rooted in water culture. The plants were subjected to either 90% (high) or 70% (moderate) relative humidity (RH) in climate chambers. Single stem roses with intact roots were transferred to 40% (low) RH to investigate the stomatal response to water stress. Moderate RH plants showed decreasing leaf conductance from day 1 to day 3 during both light and dark phases, in contrast to high RH roses, which showed almost similar leaf conductances during the 3 days. Leaf samples were studied with a light microscope (LM) and a scanning electron microscope (SEM) to quantify morphological and structural changes. Epidermal imprints showed a significantly higher number of stomata and longer stomata, as well as a wider stomatal apertures on roses grown at high RH. The high RH leaves showed a reduced density of vascular tissue and thinner leaves when compared to moderate RH leaves. Enlarged intercellular air-space (ICA) was found due to a reduced number of spongy and palisade mesophyll cells. No obvious difference in shape, size, undulation or the structure of the epicuticular wax was observed in SEM between high and moderate RH grown leaves. In conclusion, roses subjected to high RH showed differences in leaf anatomy, stomatal morphology and stomatal function, which may explain the loss of water control of these plants. Stomatal ontogenesis should occur at RH conditions below 85% to secure roses with a high postharvest quality potential.
Siriphun Sriyook, Somboon Siriatiwat, and Jingtair Siriphanich
Immature and mature durian (Durio zibethinus Murr.) fruit dehiscence was studied. Fruit were stored at 27C and 65% or 95% relative humidity, with or without 24-hour exposure to 100 ppm ethylene. Low relative humidity and ethylene increased fruit dehiscence. Spraying fruit with 100 ppm GA3 delayed dehiscence but allowed pulp ripening to continue. The plant-growth regulators IBA; 2,4-D; 2,4,5-T; BAP; daminozide; and mepiquat chloride had no consistent effects on fruit dehiscence. Various coating materials delayed dehiscence and ripening; a sucrose fatty acid ester at 1% concentration gave the best result. All coating materials reduced weight loss 7% to 14% below that of the control fruit. Fruit coated with the sucrose fatty acid ester and 100% apple wax had higher internal CO2 levels than fruit coated with any other coating. Ethylene is more important in durian fruit dehiscence than weight loss. Chemical names used: 3-indolebutyric acid (IBA); 2,4-dichlorophenoxyacetic acid (2,4-D); 2,4,5-trichlorophenoxyacetic acid (2,4,5-T); 6-benzylaminopurine (BAP); succinic acid-2,2-dimethyl hydrazide (daminozide); 1,1-dimethyl-piperidinium chloride (mepiquat chloride); gibberellic acid (GA3).