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  • Author or Editor: C.W. Lee x
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Abstract

A single immature jojoba [Simmondsia chinensis (Link) Schnedier] embryo cultured in vitro produced as many as 18 asexual embryos per explant depending on the explant size and culture media composition. Cotyledonary structures arising from embryos contained wax bodies and liquid wax identical to that of jojoba seed. The induced asexual embryos, when excised and subcultured, frequently produced callus without forming multiple embryos.

Open Access

Treatment of desert beardtongue (Penstemon parryi Gray) seed with 500 ppm (1.44 mm) GA, for 24 hours greatly enhanced germination. The optimum temperature range for seed germination was 15 to 20C in light and darkness. However, light significantly reduced seed germination when the temperature was below or above the optimum range. Stratification of seed at 5C was less effective than GA3 treatment in inducing seed germination. Imbibition of seed in 2000 ppm (34.2 mm) and 4000 ppm (68.4 mm) NaCl reduced the percentage of germination by 30% and 80%, respectively. Chemical name used: gibberellic acid (GA3).

Free access
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Abstract

The root-regenera ting potential (RRP) of one-year-old Pistacia chinensis seedlings at different growth stages was determined by recording the number of newly initiated roots during the period of 4 weeks after bare-root transplanting into a bottom misting chamber. RRP of intact pistacias was greatest when leaves were fully expanded and the terminal bud was forming (stage III) and lowest when seedlings were in a dormant condition (stages V and VI). However, seedlings disbudded before transplanting and also root cuttings showed two peaks in RRP; one at spring bud break (stage I) and the other at stage III. Removal of buds resulted in decreased RRP at stage I, but had little effect when plants were dormant. Treatments such as thiourea sprays of growing seedlings and chilling of dormant seedlings enhanced bud break and RRP. Potassium indolebutyrate applied to the root system promoted RRP of pistacia seedlings but did not eliminate the seasonal variation of RRP. Potassium indolebutyrate could replace the influence of buds only when seedlings were not in a dormant condition. Sucrose feeding via the stem substantially increased RRP at spring bud break. The results indicate that the dormant condition of buds and the availability of carbohydrates are the factors controlling the RRP of bare root transplanted pistacias.

Open Access
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The coloration of grape berries depends on the anthocyanin synthesis during maturation. The quality of berries is often decreased due to the poor color development when berries are grown under unfavorable environments and/or inadequate internal factors are involved. It has been well-known that the level of ABA at ripening is closely associated with anthocyanin synthesis; thus, the external application of ABA results in the increase of anthocyanin content even in berries grown under favorable conditions. However, the agricultural use of natural ABA is not possible because of high prices. This experiment was conducted to study the potential of STC-4771 as a substitute for ABA. The effect of STC-4771 was studied in `Kyoho', `Pione', and `Delaware' grapes. Chemicals were applied when ≈10% of berries in a cluster were colored. In `Kyoho', anthocyanin synthesis was enhanced at a concentration of 100 mg/L and there was a trend in color enhancement in `Pione', regardless of treatment concentration, between 10 to 40 mg/L. However, no clear effect was found in `Delaware' at 50 to 100 mg/L. In an in vitro experiment, anthocyanin was only increased when an adequate amount of sucrose (0.6 m) was added in the incubation medium under light. Natural ABA effectively increased the anthocyanin content of berry segments even under shading condition through four bagging materials, but no effect was confirmed in STC treatment.

Free access
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Abstract

An isogenic line, differing from ‘New Yorker’ tomato (Lycopersicon esculentum Mill.) by being homozygous for the crimson gene (ogc ), had 60% less provitamin A due to reduced β- and γ-carotene.

Open Access
Authors: and

Abstract

Black walnut toxicity to crop plants was found to be due to the juglone (5-hydroxy-1, 4-naphthoquinone) in the tree (5). Cook (3) and Massey (9) suggested that toxic material came from the roots of the walnut tree. Bode (2) believed that the toxin came from the leaves. However, the quantity of juglone in the different parts of the walnut tree has not been fully established. Daglish (4) conducted experiments on Juglans regia, in which he suggested that juglone existed in the plant as glucoside of 1,4,5-trihydroxynaphthalene. On hydrolysis it yielded glocose and alpha-hydrojuglone.. This non-toxic hydrojuglone is oxidized to its toxic juglone from exposure to the air or some oxidizing substance from roots of other plants (6). Recent experimental data (Wang, unpublished) showed that 10 ppm commercially purified juglone reduced tomato seedling growth by 50 per cent when roots were immersed in the solution. A 100 ppm application killed the seedlings.

Open Access

Abstract

Cuttings of poinsettia (Euphorbia pulcherrima Willd.) treated with a basal dip of 0.1% indolebutyric acid (IBA) alone (control) or in combination with 5% ferbam (ferric dimethyldithiocarbamate), benomyl [methyl 1-(butyl-carbamoyl)-2-benzimida-zole-carbamate], metalaxyl [N-(2,6-dimethylphenyl)-N-(methoxyacetyl) alanine methyl ester], PCNB (pentachloronitrobenzene), and ethazol (5-ethoxy-3-tricloromethyl-l,2,4-thiadiazole) did not differ in rooting index or weight. Increasing the percentage of fungicide above 5% generally reduced rooting. However, rooting was similar to the control with combinations of ferbam at 5% to 67% or metalaxyl at 20%. Fenaminosulf (p-dimethylaminobenzenediazo sodium sulfonate) at 5% to 67% reduced rooting.

Open Access

Abstract

Glyphosate [(N-phosphonomethyl) glycine] at rates of 0.0, 2.2, 3.4, and 4.5 kg/ha were applied to nursery plots that were severely infested with Canada thistle [Cirsium arvense (L.) Scop.]. The plots contained Pfitzer juniper (Juniperus chinensis L. ‘Pfitzeriana’), Hetz Juniper (Juniperus chinesis L. ‘Hetzii’), Japanese Garden Juniper (Juniperus chinesis L. ‘Procumbens’), and Tamarix Juniper (Juniperus sabina L. ‘Tamariscifolia’). Glyphosate was applied as an overspray including the junipers on September 2, 1976. Two weeks after treatment, all thistles in the 4.5 kg/ha plots were dead, while those in the 2.2 kg/ha and 3.4 kg/ha showed extreme chlorosis. Canada thistle root cuttings taken 4 days after treatment did not survive when placed in a mist bench. Good to excellent weed control was obtained with no evident phytotoxicity to the junipers.

Open Access

Abstract

Rooting of stem cuttings of Bougainvillea cv. San Diego Red, Ceratonia siliqua L., Chrysanthemum morifolium Ramat. cvs. Golden Anne and Mandalay, Euonymus japonica L. cv. Yellow Edge, Euphorbia pulcherrima Willd. cv. Eckspoint C-1 Red, Hedera helix L., Trachelospermum jasminoides [Lindl.] Lem., Juglans hindsii (Jeps.) Jeps., Pistacia chinensis Bunge, and Salix laevigata Bebb. is greatly promoted by basal dipping in H2SO4 prior to applying indolebutryic acid. Pre-treatment with NaOH results in considerable increase of rooting of cuttings of Rhododendron (Pericat) cv. Sweetheart Supreme, Bougainvillea, Liquidambar styraciflua L., Osmanthus heterophyllus G. Don cv. Ilicifolius, and Pinus radiata D. Don.

Open Access

Abstract

Ammonium sulfamate (Animate X) gave the best results for controlling resprouting of tree stumps of avocado (Persea americana Mill.).

Open Access