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- Author or Editor: D. H. Dewey x
- HortScience x
Abstract
The casual observer might assume that members of the American Society for Horticultural Science have developed only a recent interest in postharvest horticulture. This is not true; early members of the society were as much interested in the characteristics and responses of our harvested horticultural crops as they are now, or have been during the 75 years we are celebrating at this anniversary meeting. The early volumes of the Proceedings contain papers specifically directed to postharvest problems, for example, “Preliminary Report on Celery Storage Investigations” by Thompson (27) in 1915, “Notes on Storing Apples” by Gourley (12) in 1913, and “Chemical and Physiological Studies on Fruit Storage” by Magness (20) in 1921. Burroughs (9) in 1923 published on apple fruit respiration and Daly (10) related the ‘Jonathan’ apple fruit breakdown problem to fruit maturity in 1925. Early issues of the Proceedings carry listings of research projects by members. Volume 13 (2) carries at least 20 titles specifically dealing with postharvest work that ranges from shippping precooled strawberries in Ontario to the control of quality in hubbard squash in Vermont. A study of the factors influencing the keeping qualities of flowers was listed by Beal (3) in 1917. Subsequent volumes report the results of these research efforts. In the 17th volume, Magness (20) describes plans for probably the first laboratory, at least in this country, specifically designed for postharvest physiology research. It was located at Canton, Pennsylvania, privately financed and later used by Burroughs (9) in 1922 to elucidate what was later to be known as the climacteric rise in respiration.
Abstract
Postharvest treatment with thiabendazole (TBZ) or benomyl reduced the incidence of soft rot or blue mold disease caused by Penicillium expansum Thorn in ‘Mcintosh’ apple fruits. Both materials were significantly effective during cold storage or simulated marketing tests in which the apples were artificially punctured and then dipped in solutions containing rot inoculum and the chemical. All concentrations tested, 250, 500 and 1000 ppm TBZ and 75, 140, and 300 ppm benomyl, yielded rot control without affecting the respiratory activity of the apples.
Abstract
Orchard application of 300 ppm (2-chloroethyl)phosphonic acid (ethephon) to sweet cherries (Prunus avium L. cv. Schmidt) enhanced fruit abscission and decreased fruit injury from stem scar tearing when harvested without stems. Postharvest pitting of the fruit at the stem scar and the development of brown rot were reduced by ethephon. Even so, treated fruit picked without stems was unmarketable after 5 days at room temperature because of excessive amounts of decay, regardless of fungicidal treatment or storage for 0 to 6 weeks at 0 and 5°C.
Abstract
A browning disorder of the fleshy mesocarp of sweet cherries (Prunus avium L., cv. Schmidt) was related to damage caused by bruising, particularly of turgid fruit. Browning was reduced by immediate and continuous submergence of the bruised fruit in water at ambient temperatures (23–30°C). Vacuum treatment or the addition of ascorbic acid or calcium chloride did not improve the effectiveness of water in the retardation of browning. Cracking of fruit held in water for as long as 24 hours was minimized by adding sucrose or corn syrup at concentrations equivalent to the soluble solids content of the fruit. Canning of bruised cherries masked the browning discoloration and off-flavor present in fresh fruit.
Abstract
Single crystals and clusters of crystals or druses found by polarized light microscopy in tissues of Pyrus malus L. cv. Jonathan were found to contain Ca using the electron microprobe. Crystals insoluble in 20% acetic acid occurred in cells adjacent to the vascular tissues near the pedicel in mature fruit and in dormant flower buds, stems, petioles, shoot apex, roots and callus tissue. Because of deposition of calcium as crystals, calcium supplies to cortical cells of apple fruit may be limited and may result in an increased incidence of internal breakdown due to low Ca levels in those cells.
Abstract
The ionic Ca content of expressed apple juice conceivably could be used to estimate the total calcium content of fruit flesh. To evaluate this method, samples of 2 strains of ‘Delicious’ apple (Malus domestica Borkh.) were analyzed at 2- to 3-week intervals, from 4 weeks after full-bloom until full-maturity. Ionic Ca in the juice (juice Ca) was analyzed with a selective electrode, total Ca in the flesh (flesh Ca) with a plasma emission spectrophotometer. The correlation coefficient between calcium concentration in flesh vs. juice was very low during the early stages of fruit development, but increased to +0.758 (significant at P<0.0l) for samples collected 5, 3, and 0 weeks prior to fruit maturity. The correlation was generally significant at P<0.01 when all sampling dates were used (r = 0.734 for ‘Miller Spur’, +0.928 for ‘Starking’, and +0.831 for both strains). The calcium concentration in juice samples taken within 35 days of physiological fruit maturity paralleled the calcium concentration in the flesh on any given date, but was not a reliable predictor of flesh Ca concentration in fruit harvested 2 to 3 weeks thereafter.