A Promising Future for the Horticulture Profession

Abstract

s of the ASHS Southern Region 62nd Annual Meeting Orlando, Fla. 2–5 Feb. 2002 J.B. Edmond Undergraduate Competition Sunflower to Municipal Solid Waste Compost Amended Media Viviana Baiz* and E.R. Emino, Dept. of Environmental Horticulture, Institute of Food and Agricultural Sciences, Univ. of Florida, Gainesville, FL 32611-0670 Sunflower (Helianthus annus L. ‘Sunbright’) grown in two commercial potting mixes amended with 0%, 25%, 50%, 75%, or 100% (by volume) municipal solid waste (MSW)/biosolids co-compost grew as well as and in some cases better than the commercial controls. The purpose of this study was to determine the usefulness of MSW/ biosolids co-compost as a potting medium amendment. Sunflower seedlings were planted in the amended potting media in June 2001. They were harvested in August after growing in the greenhouse to full open flower and growth measurements made. Half the plants received a weekly application of 150 ppm of 20–10–20 and the other half received only water during growth in the greenhouse. At harvest the following data were collected to assess plant growth and flower quality and subjected to statistical analysis: days to flower, height, flower disc diameter, total flower diameter, flower fresh weight, total plant fresh weight, flower dry weight, and total plant dry weight. The growth and quality parameters show the addition of compost to the potting mix either resulted in plants that were not different in plant growth or had enhanced plant growth and flower quality as compared to the controls. Further, the addition of compost to the potting mix did not have any negative effects in any of the parameters measured. The addition of fertilizer increased plant height and fresh and dry weights but did not affect days to flower and flower size measurements, which is consistent with previous reports on compost utilization that there are insufficient nutrients to sustain optimal plant growth. These result provide further evidence that plants can be grown successfully in MSW/ biosolids co-compost supplemented potting mix. Variability for Antioxidant Activity in Potato (Solanum tuberosum) as Influenced by Genotype and Storage Tyann Blessington, Anna L. Hale, and J. Creighton Miller, Jr., Dept. of Horticultural Sciences, Texas AM determine the effects of storage and harvest date on antioxidant activity; and identify potential parents for the TAMU breeding program. Tubers from named varieties and advanced selections from both early and late harvest near Springlake, Texas, were evaluated in 2001. A sample of tubers was stored for two months at 4.4 °C (40 °F) and allowed to recondition for two weeks. Potato extracts from replicated tuber samples were used for the antioxidant assay. The assay involved use of 1,1-diphenyl-2-picrylhydrazyl (DPPH), which is a stable radical that absorbs at 515 nm. This assay is an easy and rapid procedure to evaluate antiradical properties of the extract. Upon reduction, a decrease in absorbance is observed, i.e., greater absorbance of DPPH in the extract indicates a smaller amount of antioxidant activity. For comparison, standard curves were prepared with known concentrations of Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), a widely used synthetic antioxidant. Significant differences were found for total antioxidant activity among genotypes in the early harvest, with Stampede Russet the highest and NDTX4304-1R the lowest. Few significant differences among genotypes were found in SR Abstracts, p. 735-757 8/14/02, 3:38 PM 737