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Tamara Angle, Jamie M. Arnold and J. Benton Storey

Evidence of professional competence is needed for those whose activities affect the well-being of the general public. Graduates of BS and MS programs in horticulture are not distinguishable from self styled individuals who assume the title of “Horticulturist” without earning it. Certification of horticultural graduates is the first step in gaining a recognition for the Horticultural Profession. ASHS has established a Certified Professional Horticultural Sub-Board of the American Registry of Certified Professionals in Agronomy, Crops and Soils (ARCPACS). Professional core requirements include courses horticultural crop management, pest management, soil science, plant physiology, botany, chemistry, and genetics. Supporting core courses include math, communication skills, and horticultural specialization courses. Applications from individual horticultural graduates will soon be accepted. Details of the curriculum, continuing education, ethics, and other eligibility requirements will be detailed.

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F.A. Bliss, J.C. Rosas and P.A.A. Pereira.

The discovery of bruchid resistance in wild beans and the demonstration that theArcelin protein is responsible for the resistance, provide an opportunity to develop resistant cultivars of common bean, Phaseolus vulgaris L. Arcelin expression is controlled by multiple alleles, which impart different levels of insect resistance. In field tests in Honduras and Brazil, backcross-derived lines with the Arl-1 allele were most resistant, especially to Mexican bean weevil. Seed mixtures of 0.80 Arl-1:0.20 susceptible and equal amounts of Arl-1,Arl-2, and Arl-3, and Arl-4 containing seeds showed resistanc elevels and seed yields similar to lines homogeneous for Arl-1. Breeding lines uniform for appearance and agronomic performance, but heterogenous for resistance genes are being tested as potential new dry bean cultivars having stable insect resistance.

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Charles S. Vavrina and William Summerhill

Thirty-four operators produced > 1.15 billion vegetable transplants in Florida in the 1989-90 season. Sales, concentrated in the winter and spring, were estimated at $30 million. Firms in the industry also made additional sales of ornamental and agronomic plants. Nine large firms accounted for 88% of all transplants produced. More than 109 acres (44 ha) of greenhouse area are allocated to containerized vegetable production. The majority (83%) of Florida s vegetable transplants were from three crops--tomatoes (45%), peppers (28%), and cabbage (10%). Only 36% of the transplants produced in the state were shipped out-of-state. This report discusses various facets of production, marketing, labor, and general business conditions of the containerized vegetable transplant industry.

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Ann C. Smigocki

Cytokinins were first recognized as a class of phytohormones for their ability to promote cytokinesis in cultured plant cells and have since been shown to be involved in a wide range of physiological processes. Most recently, the availability of phytohorm one-specifying genes from Agrobacterium tumefaciens has allowed for direct in planta manipulation of cytokinin levels. Overexpression of the isopentenyl transferase (ipt) gene by constitutive promoters led to enhanced ability of plant cells to undergo shoot organogenesis but the high endogenous cytokinin levels almost completely suppressed root development. Transient overproduction of cytokinins using promoters regulated by environmental and/or developmental factors did not inhibit regeneration of rooted plants. Transgenic plants in which cytokinin levels can be modulated are being used to characterize the participation of cytokinins in fundamental regulatory mechanisms of morphogenesis, delayed senescence, disease resistance and directed nutrient transport. The potential for using reconstructed cytokinin biosynthesis genes in economically important crops is of tremendous agronomic significance.

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V.V. Allen, B.K. Behe, T.S. Krentz and C.C. Montgomery

Organic wastes have the potential to contaminate ground and surface water supplies when overused in agronomic crop production. Poultry manure contains organic N and can be composted and partially substitute for fertilizer or peatmoss in plant production. Our objective was to determine the effects on growth of poinsettias `Freedom' and `Supjibi Red' grown in media amended with broiler litter compost (BLC). Media were developed to resemble a commercial peat-lite medium by blending BLC, peatmoss, and perlite, by volume (BLC: peat: perlite) at 1:3:4, 2:2:4, 3:1:4, and 4:0:4. Plant height, growth indices, number of fully developed bracts, and visual marketability rating were not affected by adding BLC to the media.

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F.J. Montero, J.A. de Juan, A. Cuesta and A. Brasa

The importance of rapid, nondestructive, and accurate measurements of leaf area (LA) in agronomic and physiological studies is well known, but a search of the literature revealed little information available for grape (Vitis vinifera L.). The results described herein include a comparison of 12 different mathematical models for estimating leaf area in `Cencibel'. The simplest, most accurate regression equations were: LAi = 0.587 LW (R 2 = 0.987) and LAi = 0.588 LW (R 2 = 0.994), where LAi is leaf area measured using image analysis and LW is leaf length × maximum width. Use of maximum width (W), leaf length (L), petiole length (Lp), and dry weight of leaves (DML) as single variables in the regression equations were not as closely associated with total leaf area, although their R 2 values were also highly significant.

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C.A. Sanchez

The amount of phosphorus (P) accumulated by vegetable crops is relatively small compared to nitrogen and potassium. However, large amounts of P fertilizer are often required for optimal yield and quality. Typically P added to soils is quickly converted to unavailable forms resulting in low crop utilization efficiencies. These low P uptake efficiencies have long been of economic concern and a major focus of agronomic and horticultural research. Additionally, in certain regions where crop production areas are hydrologically linked to wetland ecosystems, P fertilization is also of environmental concern. This presentation will summarize important P soil transformations, biotic and abiotic factors influencing the availability of P to crops, and P fertilizer management strategies for improved crop utilization efficiency and reduced environmental impact.

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D. Spaner, D.E. Mather and R.A.I. Brathwaite

Three local varietal types of corn (Zea mays L.)—an improved landrace `ICTA Farm Corn' derived from the Tuson population, the open-pollinated `Across 7728', and the hybrid `Pioneer 3098'—were grown at three cash-crop farms in Trinidad, and evaluated as green corn for agronomic, quality, and chemical traits. `Pioneer 3098' and `ICTA Farm Corn' had similar numbers of marketable ears and marketable yield per hectare, and both were superior to `Across 7728'. Sensory evaluations revealed that the three varieties did not differ in overall quality when boiled with Creole seasoning. When ears were not seasoned, the hybrid variety was preferred over the two open-pollinated varieties. Two-dimensional partitioning indicated that ear appearance and kernel color were the major contributors to total variation in overall quality. The importance of quality characters of green corn to local farming system priorities affects extension recommendations and breeding objectives in Trinidad.

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P. Martínez-Gómez, M. Rubio and F. Dicenta

approach applied to the main agronomical traits” (FAIR N 0 6 CT 98 4345) of the European Union. We gratefully acknowledge the assistance of Mariano Gambín in experimental work.

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Anna L. Hale, J. Creighton Miller Jr., K. Renganayaki, Alan K. Fritz, J.J. Coombs, L.M. Frank and D.S. Douches

1 Current address: USDA, ARS, U.S. Vegetable Laboratory, 2700 Savannah Highway, Charleston, SC 29414-4715. 3 Current address Dept. of Agronomy, Kansas State Univ., 2004 Throckmorton Hall, Manhattan, KS 66506. This work is part of the Dissertation of