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in HortTechnology

Rapid Diagnosis of Nitrogen Requirement for Malabar Chestnut

Chlorophyll meters can be used for convenient and non-destructive monitoring of nitrogen (N) for optimal plant growth. Peng et al. (p. 602) found that malabar chestnut attained the greatest growth with 16 mM N. When leaf dry weight was at 90% of maximum weight, the corresponding leaf N concentration was 2.65% and the chlorophyll meter reading was 46.1, which have been defined as the critical values below which poor growth resulted. Weekly fertilization of malabar chestnut with 16 mM N and leaf chlorophyll meter readings maintained between 46.1 and 58.4 are recommended.

Bulb Storage and Production Methods for Forcing Pineapple Lily

Pineapple lily has striking inflorescenses that work well as cut flowers. Carlson and Dole (p. 608) investigated the bulb storage and production methods needed to produce marketable cut flowers of four varieties of pineapple lily. While there were variety differences, stem length tended to be longer in the greenhouse than in the field. Also, high planting densities had few adverse effects on stem quality after 1 year or over 3 years of production. However, lower planting densities are recommended for long-term plantings. The bulbs do not have a pronounced obligate vernalization requirement, but flower faster when dry stored at cool temperatures.

Digital Cameras Predict Pyrethrum Yields

Pyrethrum is grown for the production of pyrethrin-based insecticides. Flower biomass is a significant component of crop yield; however, existing methods of estimating yield prior to harvest rely on destructive harvests. Scott et al. (p. 617) developed digital imagery techniques as a nondestructive alternative estimate of flower number. When sources of error, including light conditions and crop phenology were controlled, the system produced good correlation with manual sampling. The speed of image capture allowed larger spatial areas to be assessed, thus providing a better account for variability within the crop.

Plant Color May Affect Landscape Preference and Complexity

Kuper (p. 625) collected respondents’ preference and complexity evaluations for color photographs of plants and vegetation during winter dormancy, foliation, flowering, and senescence at three sites in New York and Pennsylvania. He also computed two information entropy values for each image that relate to the diversity and frequency of colors that were present. Respondents liked foliated scenes more than dormant and senescent scenes. Overall, the color changes in images affected one entropy value, but large value differences between foliated scenes and the others did not occur. Though preference and entropy values correlated, people might just like green foliage.

Ethephon Prevents Premature Flowering of Streptocarpus

Streptocarpus may flower prematurely during greenhouse production. Keeping plants vegetative prior to marketing is desirable to produce and maintain healthy, attractive, finished plants. Ethephon is a plant growth regulator that can be used to suppress flowering of ornamental plants. Currey and Flax (p. 635) report that premature flowering of streptocarpus was diminished when foliar applications of 500 to 1000 ppm ethephon were applied either 2 weeks or 2 and 4 weeks after planting. The use of ethephon in production of containerized streptocarpus may reduce hand labor and disease incidences during production by keeping plants vegetative.

Postharvest Treatment and Storage of Vidalia Onions

Vidalia onions do not store well after harvest, so methods to extend storage time are highly desirable. Bansal et al. (p. 639) found that heat or field curing did not consistently improve storability in this study; however, they were effective in some cases. Modified refrigerated atmosphere (5% carbon dioxide, 3% oxygen), refrigeration with ozone, or fumigation with sulfur dioxide prior to refrigeration did not consistently improve storability over refrigeration alone. Two weeks after removal from storage, onions rapidly lost marketability, with an average reduction of 30%.

Basil Varieties and Systems for Hydroponic Production

Basil is a popular fresh culinary herb; however, there is a lack of information characterizing the performance of different varieties and hydroponic systems. Walters and Currey (p. 645) grew 35 basil varieties in two different hydroponic systems, nutrient film technique and deep flow technique. Although hydroponic system had little effect on growth, the varieties differed widely in fresh and dry weight, height, leaf size, and branching. In order to maximize yields, producers should select the highest-yielding basil varieties available, and produce them in systems that are the most economical and efficient.

Comparing Costs of Planting Urban Trees

Budgetary resources required to plant street trees are important factors in successful tree planting and urban forest management. Green et al. (p. 651) compared the planting cost of four different planting systems (balled-and-burlapped, bare-root, pot-in-pot container grown, in-ground fabric) and showed that planting costs differed significantly due to nursery production methods. The costs associated with digging holes, moving the trees, and planting the trees were combined to determine the mean planting cost per planting system. The cost of planting balled-and-burlapped trees ($11.01) was significantly higher than any of the other production methods.

Paclobutrazol and Pinching Improve Quality of Ornamental Pepper

Ornamental pepper plants are pinched at seedling stage to control height and promote branching. Paclobutrazol, a plant growth regulator, was used at 5 to 15 ppm with and without pinching on a tall pepper variety. Sever Mutlu and Agan (p. 657) showed that pinching and paclobutrazol reduced plant height by 25% and 50%, and canopy diameter by 8% and 17%, respectively. Paclobutrazol substituted pinching at 5 ppm for growth suppression, but pinching seemed necessary for enhanced branching.

Postharvest Storage of Baby Spinach

Storage duration and temperature generally lead to degradation of the nutritional quality of spinach. Mudau et al. (p. 665) investigated the effect of postharvest storage temperature and duration on quality of baby spinach in South Africa. Baby spinach leaves stored at 4 °C maintained good quality for 4 to 6 d as compared to those stored at 22 °C. Thus, this study elucidates that as storage time and temperature increased, the quality of baby spinach leaves loses its quality.

Current Status of Children’s Gardens in the U.S.

Kwon et al. (p. 671) examined the overall distribution of children’s gardens in the U.S. and identified factors affecting development of children’s gardens within public gardens. Most children’s gardens were developed after public gardens were established. Geographically, children’s gardens were evenly distributed across public gardens, while showing a higher density on the east and west coasts. Demographic and socioeconomic factors influenced the development of children’s gardens. The number of children’s gardens as a component of public gardens is expected to increase in the future.

New Micropropagation Culture Medium for Dendrobium Orchid

Orchid micropropagation is limited by slow growth and proliferation. Tantasawat et al. (p. 681) developed a culture medium for improved growth and proliferation of ‘Earsakul’ dendrobium protocorm-like bodies (PLBs). They found that using a new medium (VW1) in two-step culture for 8 months resulted in the greatest total PLB fresh weight, number of PLBs, and growth rate with a multiplication rate of 830-fold. VW1, with supplementation of tomato and substitution of AAA group with AA group banana, promoted growth and proliferation of PLBs 2.4-fold over the control medium, and is useful in commercial micropropagation.

Sweet Corn Varieties for the Mid-Atlantic U.S.

Butzler et al. (p. 687) evaluated 23 sweet corn varieties at three sites to develop recommendations for mid-Atlantic farmers. Saleable ears produced by most varieties were not different or better than the standard variety, Temptation. Overall ear size was not different than Temptation. Ease of hand harvesting was measured as location of the primary ear and rating picking ease. Ears of four varieties were closer to the ground and three rated more difficult to pick than Temptation in 2 site years or more. Overall, mid-Atlantic farmers have a wide range of good options.

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