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  • Author or Editor: J. C. Williams x
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Abstract

Phaseolus vulgaris L. cv. Contender (green bean) treated with sea salt aerosols, similar to ambient seashore conditions displayed foliar injury from exposures of 8, 168, and 480 hr at sedimentation rates of 27, 5.7 and 1.5 μg/m2/sec, respectively. Sodium and chloride uptake was linear with time. Toxicity symptoms corresponded with a critical leaf tissue level of 2.6% Cl regardless of exposure time or sedimentation rate.

Open Access

Abstract

Sprays of 4% Off-Shoot-O (45% methyl esters of fatty acids, 4% C6, 56% C8, 38% C10, 2% C12) to container-grown Cotoneaster divaricata Rehd. & Wils., Pyracantha coccinea Roem. cv. Lalandi and Rhododendron carolinianum Rehd. at the beginning of each of 2 growing seasons increased shoots over unpruned plants but reduced fruit clusters of pyracantha. Sprays maintained hedge height of cotoneaster but not Forsythia X intermedia Zobel or privet (Ligustrum ovalifolium Hassk).

Open Access

Abstract

Various rates of ancymidol granular incorporated, granular broadcast, soil drench, and foliar spray treatments were tested on 7 breeding plant species. Generally, treatment of media affected plant height more than foliar sprays. Media treatments reduced height linearly, with increasing rates reducing plant height. Effects were similar for Salvia splendens F. Sellow ex Roem. & Schultz and Pelargonium × hortorum L.H. Bailey plants. Height of Targetes erecta L. plants was controlled most effectively by 311 to 622 mg a.i. m−3 drenches or granular incorporated. Begonia semperflorens - cultorum Hort., and Antirrhinum majus L. plant height was best controlled with granular incorporated ancymidol at rates of 155 to 622 mg a.i. and 311 to 1243 mg a.i. m−3, respectively. Germination of Tagetes and Pelargonium seed was unaffected by granular incorporated ancymidol at 78 to 311 mg a.i. m−3. Chemical names used: a-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol).

Open Access

Abstract

Applications of 0.5% dikegulac sodium (sodium salt of 2,3:4,6-bis-0-(l-methylethylidene-L-xylo-2-hexulofu-ranosonic acid) sprays produced significantly more new shoots on ‘Red wing’ or ‘King fisher’ azalea plants than manual pinching and other chemical pinching agents in 2 experiments. In 5 other experiments involving 5 other cultivars, dikegulac sodium-treated plants generally produced the most shoots, however, the shoot number was not different from shoot number on either manually pinched or 4.2% Off-Shoot-O-treated (mixture of C6 to C12 methyl ester of fatty acids) plants. Sprays of dimethyl dodecylamine caprylate at 0.2% and 0.5%, n-decanol at 2.5%, ethephon [(2-chloroethyl)phosphonic acid)] at 0.08%, and UBI-P293 (2,3-dihydro-5,6-diphenyl-1,4-oxathiin) at 1.0% gave inconsisent results but yielded shoot number comparable to dikegulac sodium in some tests. Off-Shoot-O, dimethyl dodecylamine caprylate, and n-un-decanol were destructive pinching agents at some concentrations and caused considerable plant injury. Dikegulac sodium caused minor injury and transient chlorosis. Ethephon, PBA [6-benzylamino-9(2-tetrahydropyran-2-yl)-9H-purine], and UBI-P293 did not produce any visible phytotoxicities. Shoots of plants sprayed with 0.5% dikegulac sodium and 1.0% UBI-P293 were of similar length or shorter than shoots of either manually pinched or untreated check plants 3 weeks after treatment.

Open Access

Abstract

A survey for dead spur was made by rating 8600 ‘Delicious’ apple trees (Malus domestica Borkh.) on seedling rootstock in 3 of the 4 major apple-growing areas of Washington. Only ‘Earlistripe Delicious’ was found to be appreciably affected, and no difference in incidence of dead spur was observed among the areas.‘Oregon Spur Delicious’ and ‘Earlistripe Delicious’ were rated on 5 rootstocks and no rootstock effect was detected. Dead spur symptoms on trees of other strains or cultivars and on pollenizer limbs grafted into ‘Earlistripe Delicious’ affected by dead spur suggest the disorder is transmissible. In addition, an association was noticed between cultivars with long leggy-type growth and the occurrence of dead spur.

Open Access

Abstract

Schlumbergera truncata (Haw.) Moran ‘Christmas Charm’, ‘Lavender Doll’, and ‘White Christmas’ were grown under an 8 hr natural photoperiod or an 8 hr natural photoperiod plus 4 hr of incandescent light from 10:00 pm to 2:00 am and treated with single sprays of BA at 100 and 200 ppm, GA at 25, 50, and 100 ppm, BA at 100 and 200 ppm plus GA at 25 or 100 ppm, calcium carbide at 2910 ppm, ethephon at 100 and 1000 ppm, daminozide at 5000 ppm, ancymidol at 132 ppm, and chlormequat at 1000 ppm in 2 experiments. No flower buds were initiated from any plants grown under the 8 + 4 hr photoperiod. BA applied at 100 and 200 ppm increased the number of phylloclades on ‘Christmas Charm’ plants grown under the 8 + 4 hr. BA at 200 ppm applied to plants grown under the 8 hr photoperiod caused an increase in flower bud number and earlier flowering in all cultivars tested. BA + 100 or 200 ppm 100 ppm GA applied to plants grown under the 8 hr + 4 hr photoperiod stimulated the growth and elongation of phylloclades. Applied to plants grown under the 8 hr photoperiod, BA plus GA caused the growth and elongation of phylloclades, initiation of lower buds, and induced the development of lateral phylloclades and flower buds. Ancymidol at 132 ppm and 1000 ppm chlormequat sprays produced earlier flower bud initiation and increased flower number to flower bud ratios on ‘Christmas Charm’ plants. Chemical names used: N-(phenylmethyl)-H-purin-6-amine (BA); gibberellic acid (GA); (2-chloroethyl)phosphonic acid (ethephon); butanedioic acid mono(2,2-dimethylhydrazide) (daminozide); α-cycloproply-α-4-methoxyphenyl)-5-pyrimidinemethanol) (ancymidol).

Open Access

Abstract

A container growing medium of 2 peat : 1 perlite (v/v) was limed with 0, 0.9, 1.8, 2.7, 3.6, 5.4, 7.2, and 9.0 kg·m–3 dolomite. Media were irrigated with water, providing alkalinity equivalent to 0, 38, and 371 mg·liter–1 CaCO3. Samples were incubated at 25° ± 3°C and pH determined at days 2, 5, 7, 14, 28, 56, and 84. Irrigating with even moderately alkaline water over three months increased pH substantially above levels resulting from dolomite amendments alone.

Open Access

Four southernpea (cowpea) [Vigna unguiculata (L.) Walp.] cultivars representing various combinations of resistance and susceptibility to blackeye cowpea mosaic virus (BlCMV) and southern root-knot nematode [Meloidogyne incognita (Kofoid and White) Chitwood] were used to determine effectiveness of simultaneous screening of plants for resistance to both pathogens. Plants were inoculated with both pathogens simultaneously, each pathogen separately, or left uninoculated as controls. The resistance classification of the cultivars based on treatments with only one pathogen was not different from that based on the treatment with both pathogens. Virus × nematode interaction was not a significant source of variation in BlCMV symptoms and root-knot nematode galls. Simultaneous screening for both pathogens in southernpeas appears to be a feasible option.

Free access

Abstract

Spagnum peat, perlite, vermiculite, and six media formulated (by volume) from these constituents (2:1, 1:1, 1:2 peat: perlite; 2:1, 1:1, 1:2 peat: vermiculite) were limed with 0, 0.9, 1.8, 2.7. 3.6, 5.4, 7.2, and 9.0 kg∙m−3 dolomite [CaMg(CO3)2]. Media were wet to container capacity with distilled/deionized (d/d) water, incubated at 25° ±3°C, and pH determined at day 0, 2, 5, 7, 14, 28, 56, and 84. Liming reactions in mixes could not be predicted from reactions occurring in sphagnum peat, perlite, and vermiculite constituents alone. Although sphagnum peat made the major contribution to liming reactions, both perlite and vermiculite were found to contribute to liming responses of media in which they were incorporated. The major portion of pH change due to incorporation of pulverized dolomite in peat-based media occurred within 2 days. Change in pH was complete within 14 days.

Open Access

Abstract

Operation management techniques, such as linear programming (LP), can provide producers and managers with greater quantities of information and, from this, more informed, up-to-date decisions can be made. Linear programming techniques were applied to data from ten container plant nurseries to determine possible production systems, their inputs, and to maximize profit. Models were developed for large (average, 27 ha) and small (average, 5 ha) container nurseries. Plant type and container size were used interactively as decision variables (activities) in the models. The small nursery model had 44 plant type alternatives and the large nursery model had 87. Resources included in the constraints were equipment, materials, and labor used to produce each plant type. The actual constraint values determined from survey information are provided, as well as a multiperiod model and a theoretical model.

Open Access