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Abstract
Applications of an antitranspirant (8% v/v Vapor Gard) to leaves decreased concentrations of N, P, Mg, and Ca in leaves, decreased apple dry-matter content, mass, and the amount of Ca per apple, but increased fruit firmness at harvest and after 120 days of 0°C air storage. Surfactant applications (8% v/v Tween 20) to fruit decreased fruit mass and N and Mg concentrations in leaves, but increased fruit dry-matter content and firmness after storage. Since selective application of either an antitranspirant or a surfactant to leaves or fruit, respectively, to modify the water loss balance between the fruit and leaves did not increase Ca concentrations in fruit, increased fruit firmness was probably due to reduced fruit mass and increased dry-matter contents.
Abstract
Shade treatments increased the length to diameter ratios and decreased stem-cavity depth of ‘McIntosh’ apples. Full-shade was more effective than partial-shade, and shading all year and early in the growing season affected apple shape more than shading after July 15.
Abstract
The volatile substances, carbon dioxide, ethylene, acetaldehyde, ethyl acetate, ethyl alcohol, ethyl propionate, ethyl-n-butyrate and caproaldehyde produced by the fruit from 4-year-old ‘McIntosh’ apple trees on EM 26 rootstocks in sand culture supplied with 3 levels of P and 2 levels of K in factorial combination were studied by infrared gas analysis and gas chromatography. Increased P supply increased the rate of ethylene production from apples stored for both 111 and 158 days, reduced the output of most of the other volatiles, and increased the levels of scald and core-browning. Increased K supply had little effect other than to decrease the C2H4 production in the 111-day (January) analysis.
Abstract
In ‘McIntosh’ apples, the incidence of stem-cavity browning and core browning increased with increase in fruit size. Stem-cavity browning was more severe in terminal apples than in lateral apples and decreased with increase in stem-cavity depth. In contrast, there was no consistent relationship between core browning and either position in the blossom cluster or stem-cavity shape.
Abstract
Fruit elongation, stem length, and stem-cavity depth of ‘McIntosh’ apples were increased by some gibberellic acid (GA) treatments and decreased by a fall spray of N-di-methylaminosuccinamic acid (Alar). Summer sprays of Alar and thinning had no measurable effect on apple shape. Ringing increased fruit elongation. These results are consistent with the concept that endogenous gibberellins act to control apple shape.
Abstract
The ultrastructure of floral abscission zone cells of Phaseolus vulgaris L. cv. Dark Red Kidney was studied in order to relate changes in fine structure to known changes in morphology and physiology of the foliar abscission zone of Phaseolus and to the fine structure of floral abscission zones of other plants. Major structural changes in cell walls are similar in abscission zones of senescing leaves and post-anthesis flowers but the rapidity of cellular changes is greatly accelerated in the latter. Inclusions typically found in floral abscission zone cells of Solanaceous plants are not present in Phaseolus floral abscission zone cells. Cellular changes are evaluated in terms of their potential relationship to the abscission process.
Abstract
A browning of the stem-cavity region is frequently the first externally visible storage disorder to appear in Mcintosh apples. Stem-cavity brpwning is associated with core browning and is of commercial significance for it may develop after several days at 21°C during marketing (2). A somewhat similar disorder of Sturmer apples, stalk-end scald, was reported to preferentially affect terminal apples and to be controlled by scald inhibitors (3). Casual observation suggested that both size and position in the blossom cluster influenced development of stem-cavity browning of Mcintosh apples.