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Chi Wang and Kevin L. Grueber

Control of plant height and flowering are two major problems associated with the production of Hypoestes phyllostachya Bak. (polka-dot plant). In seed-propagated cultivars, sprays of ancymidol (A-Rest), chlormequat (Cycocel), paclobutrazol (Bonzi), and uniconazole (Sumagic) were effective in inhibiting shoot growth and internode elongation at 100, 1000, 33, and 10 mg·l-1, respectively. Daminozide (B-Nine), even at 6000 mg·l-1, was ineffective compared to untreated controls. Ethephon (Florel) was effective in retarding plant growth at 500 mg·l-1, but at 1500 mg·l-1 resulted in leaf distortion and horizontal shoot growth.

H. phyllostachya was determined to be a quantitative (facultative) short day plant. Seed-propagated plants with 16 or more nodes flowered regardless of photoperiod, but flowering was more rapid under short days (SD) than under long days (LD). Application of ethephon significantly inhibited shoot elongatioo and number of flower buds formed and also increased the incidence of flower bud abortion. In seed-propagated plants, 500 mg·l-1 ethephon did not adversely affect flowering when applied at any time during the first seven weeks after the start of SD. At 1500 or 2500 mg·l-1, ethephon applied at any time during the first five weeks after the start of SD maximized the number of vegetative buds and minimized the number of viable flower buds. When applied more than six weeks after SD began, ethephon did not promote the formation of vegetative axillary buds but did promote flower bud abortion.

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Amelia L. Schweizer and Kevin L. Grueber

A study was conducted to develop and demonstrate a practical and accurate method of applying the Pour-Through nutrient extraction procedure to bedding flats and plug trays. The Pour-Through technique involves pouring a known volume of water on previously saturated medium, and collecting the leachate which is pushed out the bottom of the container. The volume of applied water necessary to conduct a bedding flat or plug tray Pour-Through was determined based on leachate pH and conductivity. The sensitivity of the Pour-Through technique when applied to bedding flats and plug trays was determined using varying rates of lime incorporated media and fertilizer. The leachate was analyzed for pH and conductivity. Results indicate that the technique can be used effectively on bedding flats and plug trays.

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Elizabeth A. Stevenson and Kevin L. Grueber

Berry College offers a unique environment for learning with 28,000 acres of forests, meadows, lakes, and streams. This distinctly beautiful setting has encouraged environmental awareness among students and faculty on campus. The construction of an academic building to house the School of Math and Natural Sciences in a previously undisturbed, wooded site prompted students and faculty to become interested in the preservation of the site's natural characteristics. Students in the horticulture program worked closely with the Director of Horticulture and the Academic Dean to develop a plan to create a landscape that was both educationally and environmentally sound.

The plan consisted of a detailed landscape design as well as the identification of the steps necessary to implement the design. The design incorporated ornamental plants and geological features native to the southeastern region of the United States with the plant species that existed on the site. The design contains such features as a wildflower meadow, an aquatic garden, rock gardens, and various native trees, shrubs, and groundcovers. Plant materials were properly labeled and brochures are made available to guests, students, and faculty interested in learning more about indigenous geological features and plant materials while touring the building and its landscape. The success of this project is due to the cooperation and participation of faculty, staff, and students and represents a unique learning opportunity.

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Robert D. Wright, Kevin L. Grueber and Carol Leda

The relationship between medium nutrient levels extracted with the pour-through (PT) and the saturated medium extract (SME) procedures was investigated. These procedures were used as indicators of plant nutrient uptake and growth of poinsettia, Euphorbia pulcherrima Wind. ex. Klotzch. The medium nutrient levels and electrical conductivity associated with optimal plant growth were about two times greater for PT than for SME. The pH values were similar for both procedures. Regression analysis of the relationship between applied and extracted nutrient levels gave higher R2 values for the SME, although the relationship for PT was acceptable. Both procedures provided an acceptable and similar correlation between the level of NO3-N extracted and the level of N absorbed by the plants. The results demonstrate the utility of both PT and SME as indicators of the nutritional status of a greenhouse medium.