Foliar sprays or root dips of synthetic abscisic acid (s-ABA) have shown to reduce the transpiration rate and subsequently prolong postharvest longevity in a select group of herbaceous ornamental crops. The objective of our study was to determine the impact of s-ABA on postproduction performance of seed impatiens in greenhouse or low light conditions. Market ready Impatiens wallerana `Xtreme Scarlet' plants were sprayed or the root substrate was drenched with s-ABA at 250 or 500 mg·L–1 then boxed for 48 h to represent shipping conditions. Flower number was measured 3 days after application, and again after plants were hydrated following the day when the last treatment wilted 0, 2, 4, 8, 16, or 24 days after application. Visual quality ratings were made 0, 2, 3, 4, 8, 11, 16, or 19 days after application and again after plants were re-irrigated. Drenching the substrate with s-ABA at 500 mg·L–1 maintained foliage and flower turgidity up to 8 days in the greenhouse environment and 16 days in the low light environment. Substrate drenches at 500 mg·L–1 dramatically decreased flower number after removal from the shipping box under greenhouse conditions, and in the low light environment drenching the substrate at 250 mg·L–1 produced similar visual quality results to 500 mg·L–1 16 days after treatment. Plants drenched at 250 mg·L–1 also had the same number of flowers 3 and 20 days after treatment, when compared to 500 mg·L–1. Therefore, impatiens growers should drench the root substrate with s-ABA at 250 mg·L–1 to reduce labor costs associated with hand-watering and prolong postproduction performance in low light conditions, such as indoor retail conditions.
James L. Gibson and Shannon Crowley
Ryan J. Hayes, Carlos H. Galeano, Yaguang Luo, Rudie Antonise, and Ivan Simko
Lettuce is a perishable leafy vegetable crop marketed as whole heads or as cut leaves packaged as ready-to-eat salads. Postharvest quality and shelf life are important characteristics for consumers and lettuce shipping companies. Cultivars bred with
Anna Marín, Elizabeth A. Baldwin, Jinhe Bai, David Wood, Christopher Ference, Xiuxiu Sun, Jeffrey K. Brecht, and Anne Plotto
, increasing the risk of developing pathogens ( Baldwin, 2007 ). Therefore, fresh-cut fruit shelf life is considerably shorter than for whole fruit. To delay fresh-cut fruit deterioration, processors tend to cut mangoes on reception without preripening to avoid
Peter M.A. Toivonen
microperforated film at 4.5 °C for up to 12 d. According to the authors’ recollection, the shelf life could be doubled from 4 to 8 d using 1-MCP treatment and that was probably the result of the effects seen in the visual quality rating. However, 1-MCP only
Hiroshi Iwanami, Shigeki Moriya, Nobuhiro Kotoda, and Kazuyuki Abe
storage in our experiment. This possibly means that the strength of adhesion between neighboring cells determines the fate of a cultivar that has a low reduction rate of turgor whether the cultivar has severe mealiness or long shelf life. On the other hand
Jaysankar De, Aswathy Sreedharan, You Li, Alan Gutierrez, Jeffrey K. Brecht, Steven A. Sargent, and Keith R. Schneider
, respectively. The short postharvest shelf life of fresh fruit like blueberries requires efficient technologies for postharvest cooling, handling, and storage to keep losses to a minimum. Blueberries, like many other small fruits that are consumed raw, have the
Konstantinos G. Batziakas, Shehbaz Singh, Kanwal Ayub, Qing Kang, Jeffrey K. Brecht, Cary L. Rivard, and Eleni D. Pliakoni
been successfully implemented for reducing postharvest losses by extending the shelf life and maintaining the quality of a variety of fruits and vegetables ( Domínguez et al., 2016 ; Kader et al., 1989 ; Mampholo et al., 2015 ; Zhang et al., 2006
Ahmed El Ghaouth, Joseph Arul, Rathy Ponnampalam, and Francois Castaigne
The effect of chitosan coating on green peppers and cucumbers stored at 13°C and 85% R.H. on weight loss, quality and respiration was assessed. Chitosan coating markedly reduced the weight loss of both green peppers and cucumbers, with greater effect at higher concentration. In addition, color loss, wilting, decay and respiration was significantly lower in coated fruits than in the control.
The results of this study indicate that the mechanism by which chitosan coating delay senescence in green peppers and cucumbers is more likely due to its ability to alleviate water stress than to modify the internal microatmosphere.
Navjot K. Mangat and Jiwan P. Palta
The pericarp tissue of red mature tomato (Lycopersicon esculentum cv. Gagliano) was used to exctract polygalacturonase (PG) enzyme. The technique for assaying PG activity involves measurement of released reducing groups that were linked together in pectin. Since the crude extract of PG from pericarp will contain considerable reducing groups, we found that repeated washings of the cell wall pulp removed much of the sugars and thus minimized the background absorbance without loss of PG activity. There is an inherent perplexity concerning the selection of blank for PG assay. This is because (i) the enzyme extract contains both the substrate (pectin) and product (free reducing groups) involved in the reaction; (ii) the color development with cyanoacetamide requires heating for 10 min. Thus, even though the reaction is terminated with borate buffer (pH 9.0) the breakdown of pectin continues chemically by heat; (iii) the absorbance from both pectin and enzyme together at zero time termination was always lower than the sum of absorbances from pectin alone and enzyme alone. This suggests that when together in the same tube, the enzyme appears to protect the pectin from physical breakdown during the period of 10 min. boil needed to develop color using the cyanoacetamide. Thus, the most appropriate blank is processing separately the solutions of enzyme alone and substrate pectin alone for color development and then adding the two absorbances. Using this improved assay we found that lysophosphatidylethanolamine (LPE) inhibited tomato PG activity. This inhibition appears to depend on the ripening stage of the fruit. Our results suggest that LPE is able to impart firmness to tomato fruit by reducing the PG activity, which in turn could protect the pectin/middle lamellae from enzymic breakdown. The effects of LPE on PG activity are distinct from those of Triton X-100 and lysophosphatidylcholine.
Charles F. Forney
Freshly harvested heads of `Cruiser' or `Paragon' broccoli (Brassica oleracea L. Italica group) were heat treated by holding in water for 1 to 40 min at 42, 45, 48, 50, or 52C. Control heads were held in air at 20C or in 25C water for 40 min. Controls turned yellow in about 3 days at 20C. Treatments at 42C delayed yellowing by 1 or 2 days, while treatments of 45, 48, 50, and 52C prevented yellowing up to 7 days at 20C. Hot water treatments had no effect on water loss of broccoli during storage. Incidence of decay was greater in treated broccoli stored wet compared to the dry control. However, when free water was removed by spinning following treatment, no difference in decay was observed. Treatment of broccoli at 52C for 3 or more min sometimes induced a distinct off-odor. When broccoli was held at 0C for 3 weeks following treatment no differences were observed between control and treated broccoli. However, when broccoli was warmed to 20C following storage at 0C, yellowing of treated broccoli was inhibited. Hot water treatments also delayed senescence at 20C when broccoli was treated following 3 weeks of storage at 0C.