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  • Author or Editor: Julian C. Crane x
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Abstract

Fig fruits treated with 2-chloroethylphosphonic acid (Ethrel) during Period I (initial rapid growth) ceased growth and abscissed. Treatment during Period II (slow growth) stimulated growth and maturation, but quality equal to that of later maturing control fruits was not attained unless the fruits were treated late in Period II. Although Ethrel-treated fruits matured from two to more than three weeks earlier than control fruits, their ultimate average diameter, fresh and dry weights were not significantly different from the control.

Open Access

Abstract

Apricots on branches sprayed with Ethrel at the beginning of pit hardening abscised, whereas similar treatment with 2,4,5-T stimulated fruit growth and decreased drop. In the stem, gum ducts were formed in the xylem after treatment with Ethrel but not with 2,4,5-T, both at 100 ppm concentrations. Both Ethrel and 2,4,5-T stimulated cambial activity in petioles and midveins, thus increasing phloem and xylem tissues. Both growth regulators induced tylosis formation in petiole xylem. 2,4,5-T treatment caused increase in petiole diameter and leaf blade thickness, through increasing endopolyploidy and thus cell size in ground tissue of the petiole, and in mesophyll, epidermis and vascular bundle sheathes in the leaf blade. Ethrel caused little if any increase in cell size in those tissues, and therefore no obvious increase in petiole diameter and leaf blade thickness.

Open Access

Abstract

As with most other drupe fruits, curves representing growth in length and diameter of seeded pistachio nuts reveal 3 distinct periods, 2 cycles of rapid growth separated by 1 of slow growth. Growth curves of seedless pistachios, however, are similar to those of almond (a dry drupe) in which a rapid growth phase is followed by one of inconsequential growth. Embryo development in the pistachio is delayed longer than in other drupes; it is not evident macroscopically until about 30 days after completion of the initial period of pericarp growth. Seedlessness, the symptoms of which are not manifest until after most pericarp growth has occurred, frequently appears to be associated with necrosis of the apical portion of the funiculus supporting the seed, and consequent seed abortion.

Open Access

Abstract

Gibberellic acid (GA3) induced cell division in subapical meristems of quiescent terminal vegetative buds and brought about bud opening and stem elongation in pistachio (Pistacia vera L.). When the subapical meristems in rachis primordia in lateral inflorescence buds were undergoing cell division, GA3 application enhanced cell division and brought about elongation of the rachis. However, application of GA3 to inflorescence buds when cell division in the subapical meristem of the rachis essentially had terminated, induced cell division in the bases of the buds with subsequent bud abscission.

Open Access

Abstract

In pistachio (Pistacia vera L. cv. Kerman), when flowers did not set or when young fruits were removed, pedicels and/or portions of the rachis or of the primary branches subtending these parts abscised. Inflorescence buds on fruiting shoots and those on nonbearing shoots treated with (2-chloroethyl) phosphonic acid (ethephon) also abscised. Abscission of the above organs, as well as of leaflets and compound leaves, occurred in definite zones. The first manifestation of the abscission process was transverse cell division in the abscission zone. A separation layer developed in the distal portion of the abscission zone in these organs. The newly formed cells in the proximal area of the abscission zone of pedicels, rachises, and ethephon-treated inflorescence buds became protective layers. However, the counterpart in abscising inflorescence buds on fruiting shoots was largely degraded as abscission progressed. Abscission of mature fruits of pistachio was not preceded by cell division but involved separation and collapse of cells in the fruit mesocarp and exocarp surrounding the distal portion of the pedicel.

Open Access

Abstract

Plastid pigments in the fruit skin of fig (Ficus carica L. cv. Mission) were extracted in acetone:0.1 N NH4OH (9:1 v/v) and purified by thin layer chromatography. Spectral analysis indicated the pigments were chlorophylls a and b, β-carotene, lutein, violaxanthin, and neoxanthin. These constituents were similar to those found in the leaves. Carotenoids present in the skin of bluish-black mature fruits were the same as those present in green, immature fruits.

Open Access

Abstract

Abscission of inflorescence buds increased progressively as leaf area decreased or number of nuts per branch increased. The data strongly indicate that dominance of the developing seed over the inflorescence buds in competition for carbohydrates might be responsible for bud abscission. However, the possible involvement of a hormone(s) originating in the leaves should not be overlooked.

Open Access

Abstract

Leaf morphology of Pistacia atlantica Desf., P. chinensis Bunge, P. integerrima Stewart, P. khinjuk Stocks, P. lentiscus L., P. mexicana HBK, P. mutica F.&P., P. vera L., and P. weinmannifolia Poisson were compared. P. lentiscus, P. mexicana, and P. weinmannifolia were hypostomatic while the other species were amphistomatic. Leaves of P. vera, which are oriented randomly, appeared to be isolateral, while leaves of the other species are dorsiventral and are oriented horizontally. Differences in the length and density of the ab- and adaxial palisade cells and in the shape of the spongy parenchyma cells were noted among species. In an effort to relate structure to function, the daily patterns of carbon dioxide assimilation rate, A, and leaflet conductance, g, to water vapor among P. atlantica, P. integerrima, and P. vera were determined under field conditions. The mean maximum Pn rates were 2.1, 1.0, and 2.0 nmol CO2 cm−2 s−1, respectively.

Open Access