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  • Author or Editor: H. C. Dostal x
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Abstract

The obvious changes which occur during ripening have long been the mainstay of man’s evaluation of fruit and vegetable quality. Influence of environment on these changes have been investigated over the past decade. More recently, research has focused on the basic physiological processes which occur prior to and in close association with the manifested ripening changes.

Open Access
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Abstract

Aroma transfer is a problem common to both mixed and unmixed storage of agricultural commodities. The deleterious effect on palatability of certain fatty products by such materials as apples is well documented. Too, certain apple varieties may suffer physiological stress due to emanations by other varieties of apples. A number of methods for removal of objectionable odors in storage have been suggested in past years. Each of these systems has distinct advantages; yet, none is universally effective.

Open Access
Authors: and

Abstract

Total yield and percentage of ripe tomato fruit were significantly increased following single foliar applications of 0.84 lb. per acre (2-chloroethyl)phosphonic acid (ethephon). Maximum responses were noted at 14 days after treatment. Three tomato cultivars seeded on 3 dates responded similarly. Seventeen days after ethephon application at the 15 percent ripe fruit stage, useable ripe fruit yield was increased to more than 90 percent of the total fruit yield, compared to 59 percent useable ripe fruit for the control. The application of ethephon advanced harvest by 12 to 14 days, with an increase in useable ripe fruit yield of 5 to 10 tons per acre over the optimum potential of the normal ripening rate for single-harvest culture.

Open Access

Abstract

Brief, daily mechanical disturbance reduced dry weight gain as well as shoot elongation of tomato (Lycopersicon esculentum Mill. cv. Kokomo). Tactile (thigmo-) and vibrational (seismo-) stimulation of leaf surfaces increased leaf diffusive resistance and decreased transpiration in both stress-conditioned and unstressed control plants. The transitory nature of these responses suggests that prolonged reduction of stomatal aperture was not the cause of the dry weight or growth reductions. Changes in respiratory rates and photosynthetic efficiency also were ruled out. However, growth in dry weight paralleled increase in leaf area for stressed and unstressed plants, suggesting that reduced net photosynthesis was the result, rather than the cause, of retarded plant growth.

Open Access

Abstract

Application of (2-chloroethyl)phosphonic acid (ethephon) or ethylene gas to attached rin fruit of tomato (Lycopersicon esculentum Mill.) induced ripening as measured by lycopene development, fruit softening, increased total soluble solids, and promotion of normal tomato flavor.

Open Access

Abstract

The Rumex obtusifolium L. bioassay was used to determine the level of gibbereUin (GA)-like substances in methanol extracts from peach mesocarp tissue. Applications of succinic acid-2,2-dimethylhydrazide (SADH) to peach trees did not reduce the level of endogenous gibberellins in the mesocarp tissue of fruits sampled at various times. These data suggest that SADH does not hasten maturity of peaches by decreasing endogenous GA levels.

Open Access

Abstract

Succinic-acid-2,2-dimethylhydrazide (SADH) applications hastened the maturity of peach fruit when trees were sprayed during fruit growth stages I, II and III. The greatest hastening of fruit maturity was evident with high concn of SADH (4000 and 8000 ppm) applied between the mid-point and the end of stage I. The optimum concn during stage II for hastening maturity was 1000 ppm. Applications of SADH in stage III hastened fruit color development but had little effect on other indices of maturation. Five of 6 SADH analogues were effective in hastening fruit maturation when applied in the first half of stage II. The growth retardants Amo 1618 and £CC did not hasten peach fruit maturation.

Open Access

Abstract

(2-Chloroethyl)phosphonic acid (ethephon) applied at 2.9 kg/ha to plants of tomato (Lycopersicon esculentum MilUwhen 20-30% of the fruit were ripe, did not appreciably affect pH, total acidity, exterior color of the fruit, or consistency of the processed products. Organoleptic analyses of tomato juice indicated no differences in flavor between samples from ethephon-treated and untreated fruit. Chromatographic separation of fruit carotenoids showed that treated fruit synthesized more lycopene than controls.

Open Access