This review is restricted to the effects of combinations of at least two of the following factors—O2, CO2, and temperature—that may interact with ethylene and relative humidity to induce disorders in vegetables.
In three trials over 3 years, foliar BA applications for fruitlet thinning of `Empire' apple (Malus domestica Borkh.) trees produced small and inconsistent effects on flesh firmness at harvest and after air storage. Soluble solids concentrations at harvest and after air storage were consistently increased by BA alone or together with GA4+7 [Promalin (PR)], and were also increased by CB in one trial. Starch hydrolysis was slightly delayed by BA applications in 1990. Ethylene evolution at harvest was increased by NAA in 1988 and slightly increased by PR applied 29 days after full bloom (DAFB) in 1990, while poststorage ethylene evolution was stimulated by BA and PR treatments in 1990 except BA at 29 DAFB. Incidence of poststorage disorders was low and largely uninfluenced by thinning treatments. Chemical names used: N-(phenylmethyl)-1H-purine-6-amine [benzyladenine (BA)]; BA plus gibberellins A4 and A7 (GA 4+7) [Promalin (PR)]; 1-naphthaleneacetic acid (NAA); 1-naphthalenyl methylcarbamate [carbaryl (CB)].
My congratulations to the authors of the ASHS Publications Manual. I expect the manual is the most complete and up-to-date reference of its kind available. It should be required reading of all authors submitting manuscripts to ASHS publications, could very well serve as a guide to writing theses, and would be helpful to anyone writing in English.
The permeability of the flesh of ‘McIntosh’ apples (Malus domestica Borkh.), as measured by electrolyte leakage, appeared to follow a phasic pattern with aging. A phase of initial reduction of permeability preceded a large increase, then there was a slight transient decrease in permeability, and finally a slight increase. Field treatment with butanedioic acid mono (2,2-dimethylhydrazide) (daminozide), early harvest, controlled atmosphere and low-pressure storage as well as a low storage temperature (0.5 vs. 3.5°C) favored a reduction of permeability. The effect of low-pressure storage on the reduction of permeability appeared to be due to a delay of ripening as evident in delayed C2H4 production; that of controlled-atmosphere storage seemed to be due to some effect of the atmosphere other than one upon ripening, because the fruit produced C2H4 upon removal from storage.
Covering apples with foil bags about 1 month after bloom to harvest had no effect on fruit size or starch content, had inconsistent effects on fruit firmness, and reduced soluble solids, anthocyanin and chlorophyll. Uncovering fruits at various times before harvest allowed formation of anthocyanin, maximum amounts being dependent on cultivar and time of exposure.
A midsummer foliar daminozide (DZ) application (750 mg a.i./liter) to `Macspur McIntosh'/M.7 apple trees (Malus domestics Borkh.) reduced preharvest drop and retarded flesh firmness loss and starch hydrolysis when tested at harvest; DZ also reduced fruit ethylene production at harvest and after 19 weeks of storage at 0.5C. Root pruning at full bloom (May) resulted in increased soluble solids concentration (SSC) and firmer flesh and less starch hydrolysis at harvest, but not consistently each year. Full-bloom root pruning reduced the incidence of stem-cavity browning and brown core, but again not each year. Full-bloom root pruning did not influence ethylene evolution at harvest but did reduce post-storage ethylene evolution in two of three seasons. Full-bloom root pruning generally was less effective than DZ in altering fruit behavior, while root pruning later than full bloom had virtually no effect. Trunk scoring or ringing increased SSC and retarded loss of flesh firmness before harvest and following storage, but had little effect on starch hydrolysis. Scoring or ringing decreased incidence of some disorders and reduced post-storage ethylene evolution, although these treatments had little effect on ethylene production at harvest. Trunk scoring influenced some fruit characteristics more strongly than DZ. Fruit size was not affected by any treatment in any year. Chemical name used: butanedioic acid mono (2,2 -dimethylhydrazide) (daminozide).
In situ measurements of impedance and resistance of fruits have not found general use in measuring fruit maturation, senescence, and physiological condition despite some advantages over measurements of electrolyte leakage (exosmosis) from excised tissue. The advantages are ease and rapidity of techniques and preservation of the fruit for other analyses. The disadvantages or difficulties are the small measurable differences, cost and suitability of instrumentation for rapid measurements, choice of frequency of imposed current, suitable placement of electrodes to compensate for variation, and interpretation of data in physiological terms relating to membrane permeability or other developmental changes. With proper selection of methods and instrumentation, in situ impedance and resistance measurements have a potential not yet exploited.
Cabbage (Brassica oleracea var. capitata, cv. Quick Green Storage) and carrots (Daucus carota L., Nantes type) were stored successfully in low pressure storage (LPS) at 50-60 Torr and 1° and 5°C with ‘Delicious’ apple fruit (Malus domestica Borkh.). LPS conditions minimized the effect of the ethylene produced by the apples on leaf senescence and abscission of cabbage, and formation of a bitter flavor in carrots.