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  • Author or Editor: A. Jones x
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The most popular Ficus for interior conditions is F. benjamina, which has many clonal selections but still drops its foliage too readily. We compared 4- to 5-foot-tall, shade-grown plants of F. nemoralis, F celebensis, F. binnendykii `Alii,' F. oblongifolia (?), and a selection of F. benjamina thought to be `Gulfstream' with F. benjamina `Exotica' that were transferred to the Hamilton Library of the Univ. Hawaii after 14 weeks under 50%, 65%, or 85% Saran shade. During a 9-week evaluation period, new growth, leaf drop, and photosynthesis were determined. Little new growth developed on any plants during the evaluation period in the library. Leaf loss was greatest for F. benjamina `Exotica,' followed by F. celebensis, while the other four species suffered little leaf loss. Leaf loss was greater for plants grown under 50% shade than for 80% shade, while leaf loss from plants produced under 65% shade was either greater or less than 80% shade, depending on species. Leaf loss was greater in low light sites (13.6 μM/m2 per s) than in medium conditions (20 μM/m2 per s) or near windows (29 μM/m2 pers). After the observation period, the plants were to be removed, but library staff asked to retain many plants as they liked the improved atmosphere the plants gave their office and library settings. Most popular for retention were F. binnendykii`Alii,' F. benjamina `Gulfstream,' and F. benjamina `Exotica,' which still looked good despite its high foliage loss initially. The weeping habits of F. nemoralis and F. oblongifolia (?) were not as desirable because of the space they required, although they are performing well after nearly 12 months in the library. F. celebensis, despite its attractive growth habit and foliage, was a disappointment as it lost many leaves and, over 12 months, developed chlorosis and exudation problems.

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Abstract

Seed extracts of a number of fresh market cultivars of tomato (Lycopersicon esculen-tum Mill.) were subjected to starch gel electrophoresis and stained for alcohol dehydrogenase activity to investigate the possibility of utilizing allozymic variation to determine genetic purity of F1 hybrids. Of the varieties tested 46% proved amenable to the test. This method offers a practical and rapid means of estimating seed contamination frequencies in commercial seed lots as well as distinguishing hybrids from parental lines in the field.

Open Access
Authors: and

Abstract

F1 hybrids between high sugar and acid lines of tomato (Lycopersicon esculentum Mill.) were rated higher in sweetness, ‘tomato-like’, and overall flavor intensity than the high-acid parent common to the crosses. Titratable acidity and soluble solids content were responsible for most of the observed differences in sweetness. The results indicate that improved tomato flavor can be achieved by genetically enhancing sugar and acid content. Rapid gains in flavor quality might be achieved in horticulturally acceptable types through F1 hybrids.

Open Access
Authors: and

Abstract

‘Sierra Sweet’ is an attractive, fresh market tomato (Lycopersicon esculentum Mill.) developed for high soluble-solids content in ripe fruit, an important contributor to tomato flavor. ‘Sierra Sweet’ has value as a germplasm source for enhanced soluble solids and multiple disease resistance as well as a parent in the production of commercial hybrids.

Open Access
Authors: and

Abstract

‘Garden Sunshine’ is an attractive, tobacco mosaic virus-resistant, bell type (sweet) pepper (Capsicum annuum L.) with lemon-yellow immature fruit which ripen to a bright red color. It is adapted to California growing conditions, and was developed as a unique home garden type. ‘Garden Sunshine’ fruits have improved flavor and canning attributes.

Open Access

Abstract

Root injury of sweet potato (Ipomoea batatas (L.) Lam) was significantly increased when eggs of banded cucumber beetles (Diabrotica balteata (LeConte)) in a agar-water mixture were applied at preroot enlargement. This technique should prove useful in screening sweet-potato lines or cultivars for insect resistance.

Open Access

Abstract

The establishment of an average elemental composition for snap bean to satisfy nutritional labelling requirements is probably not possible. Analysis for the elemental content of 40 frozen snap bean samples collected at 8 locations in the United States revealed a wide range in concentration for the 18 elements determined. Several causes for this wide variation are suggested.

Open Access

Green roofs provide multiple environmental and economic benefits, such as roof surface temperature reduction, reduced internal cooling needs, storm water management, and extended life span of roofing materials. However, green roof substrates must be relatively lightweight, so it is typically coarse with limited water holding capacity. We hypothesize the physical characteristics that make the substrates successful on a roof are likely to reduce seed germination. For this study, we tested the germination of three perennial species and one annual: shasta daisy (Leucanthemum ×superbum), yarrow (Achillea millefolium), and indian blanket (Gaillardia pulchella), and pinto bean (Phaseolus vulgaris) (as a control) across five different substrates: peat/perlite/large expanded shale, compost/sand/expanded shale, compost/black dirt/expanded shale, compost/expanded shale, and peat/perlite (control). Substrate physical and chemical properties were analyzed, and a germination test conducted using a randomized complete block design, with each species/substrate combination appearing once per block. Germination was defined as seedling emergence, and monitored every 7 days for 28 days. Pinto bean had the highest germination (76.2%) across all substrates, compared with 43.4% for indian blanket, 40.4% for yarrow, and 23.0% for shasta daisy. Seed germination, across all species, was lower in green roof substrates. Germination success was very strongly correlated with seed length, seed width, and seed area, while no relationship was found between seed germination and substrate pH or electrical conductivity (EC). Therefore, it is likely that the physical characteristics of green roof substrates create poor conditions for seed germination.

Free access

The relationship among the free amino acid content, the expression of genes related to branched-chain amino acid metabolism {branched-chain aminotransferase [BCAT], α-keto acid decarboxylase [pyruvate decarboxylase (PDC)], and threonine deaminase [TD]}, and the production of branched-chain (BC) esters during ripening and senescence in ‘Jonagold’ apple fruit (Malus ×domestica) was studied. Eighteen amino acids were measured by liquid chromatography coupled with tandem mass spectrometry. The content for all amino acids changed with developmental stage and some shared similar patterns of accumulation/diminution. The pattern for isoleucine differed from all other amino acids, increasing more than 20-fold during the ripening process. The onset of the increase was concomitant with the onset of increasing ethylene and BC ester production and the content remained elevated even during senescence. The elevated isoleucine levels are consistent with an increase in the flux through the pathway leading to the formation and degradation of the isoleucine precursor α-keto-β-methylvalerate, which is used for production of BC esters containing 2-methylbutanol and 2-methylbutanoate moieties. Unexpectedly, the content of threonine, the amino acid from which isoleucine is thought to be derived in plants, did not change in concert with isoleucine, but rather declined somewhat after ripening was well underway. Patterns in the expression of some, but not all, of the putative BCAT and PDC genes appeared to reflect the rise and fall in ester formation; however, the expression of putative TD genes did not change during ripening. The patterns in gene expression and amino acid content are interpreted to suggest that the synthesis of α-keto-β-methylvalerate and isoleucine during apple ripening may depend on an as yet uncharacterized pathway that bypasses threonine, similar to the citramalate pathway found in some bacteria.

Free access

Abstract

A model which predicts terminal and spur leaf emergence of sour cherry (Prunus cerasus L. cv. Montmorency) grown near East Lansing, Michigan was developed from biological and temperature observations made in orchards near Egg Harbor, Wisconsin. Leaf number of spur and terminal shoots was more highly correlated with degree-day accumulation at a base of 4°C starting April 19, than with time. Leaf number on individual shoots was linear with respect to degree-day accumulation; however, not all growth on an individual tree was synchronous, and the plot of average leaf number vs. time was slightly curvilinear. Terminal buds set about 350 and 850 degree-days after first leaf emergence for spur and terminal shoots, respectively, regardless of location. Leaf size increased linearly with degree-day accumulation until full leaf expansion. At maturity terminal leaves were about 50% larger in area than spur leaves. Foliage growth was greatest during stage I and early stage II of fruit growth, and may compete with the fruit for assimilates needed for growth.

Open Access