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- Author or Editor: Carl Niedziela x
Plug seedlings of lisianthus [Eustoma grandiflorum (Raf.) Shinn. `Mariachi'] and stock [Matthiola incana (L.) R.Br. `Cheerful White'] were planted on 20 Nov. 2003 followed by plug seedlings of snapdragon (Antirrhinum majus L. `Maryland') and seeds of sunflower (Helianthus annuus L. `Sunbrite') the next day. Each species was planted in four production systems (harvest lugs, lay-flat bags, pots, and polystyrene trays). Production systems were randomized in a Latin-square design with four replications of each system. Each treatment plot was 0.7 m × 1.1 m. Planting densities was 62 plants/m2 for stock and 31 plants/m2 for lisianthus, snapdragon, and sunflower. The harvest lugs were 55 cm × 37 cm × 16 cm. The lay-flat bags were 114 cm × 30 cm × 3 cm. The pots were 25 cm bulb pans. The polystyrene trays were 67 cm × 34 cm × 5 cm and contained 32 square cells. All of the containers were filled with the same tobacco germination media. The plants in the harvest lugs, lay-flat bags and pots were irrigated daily with 150 mg·kg-1 of N from 20N-4.4P-16.6K. The plants in the polystyrene trays were floated on a solution of 150 mg·kg-1 of N from 20N-4.4P-16.6K. Float solutions were monitored and adjusted weekly for volume and fertilizer concentration. Individual stems were harvested from each species at the appropriate stage of development for market. The weight and length of individual stems were recorded. Rate of growth and maturation differed between production systems and locations in the greenhouse. Detailed results will be presented.
Two studies each were conducted with Brassica oleracea L. Italica Group `Packman' and B. o. Capitata Group `Greencup' cabbage. Seed was germinated and grown in a commercial soilless media contained in polystyrene flats floating on a nutrient solution from commercial fertilizers. The solution macronutrient concentrations (mM) were 6.4 NO3, 4.3 NH4, 0.5 H2P04, 2.1 K, 2 Mg, and 2 S04. The solution micronutrient concentrations (μM) were 6.8 Fe, 4.7 B03, 3.4 Mn, 0.42 Cu, 0.30 Zn, and 0.008 MoO4. Three cell sizes were used: 15 cm3 (253 cells/tray), 26 cm3 (200 cells/tray), and 36 cm3 (128 cells/tray). Each cell had a depth of 6.5 cm. There were no differences in the mean plant height or weight of broccoli due to cell size in either experiment. There were also no differences in mean plant height of cabbage in either experiment. However, mean plant weight was heavier in the 36 cm3 (5.4 g) cell size than the 15 cm3 (3.4 g) cell size in the first experiment and heavier in the 36 cm3 (3.9 g) and 26 cm3 (3.4 g) cell sizes than the 15 cm3 (2.8 g) cell size in the second experiment.
Plug seedlings of Celosia cristata L. `Persimmon Chief' were planted in four production systems (harvest lugs, lay-flat bags, pots, and polystyrene trays) on 7 May 2004. Production systems were randomized in a Latin-square design with four replications of each system. Each treatment plot was 0.7 m × 1.1 m. Planting density was 31 plants/m2. The harvest lugs were 55 cm × 37 cm × 16 cm. The lay-flat bags were 114 cm × 30 cm × 3 cm. The pots were 25 cm bulb pans. The polystyrene trays were 67 cm × 34 cm × 5 cm and contained 32 square cells. All of the containers were filled with the same tobacco germination media. The plants in the harvest lugs, lay-flat bags and pots were irrigated daily with 150 mg·g-1 N from 20N–4.4P–16.6K. The plants in the polystyrene trays were floated on a solution of 150 mg·g-1 N from 20N–4.4P–16.6K. Float solutions were monitored and adjusted weekly for volume and fertilizer concentration. Individual stems were harvested at the appropriate stage of development for market. The fresh weight, stem length and flower diameter of individual stems were recorded. Stems produced in float trays had the lowest fresh weight (162.2 g). Stems grown in harvest lugs (363.5 g) weighed more than those in pots (298.4 g) but not lay-flat bags (338.4 g, lsd 0.05 = 42.7). Stems grown in float trays (88.8 g) were shorter than lay-flat bags (121.5 g), harvest lugs (120.5 g), and pots (113.5 cm, lsd 0.05 = 10.5). Flower diameter did not differ between production systems (mean diameter = 7.2 cm).
A new tube method for determining physical properties in container substrates was compared to an existing system. While both offer the advantages of undisturbed substrate and measurement of properties without altering the geometry of the substrate in the container, the tube method is easier to conduct. Both methods proved equally effective for determining air-tilled porosity, container capacity, total porosity, bulk density, and particle density.
The goal of this study was to expedite galax seed germination in vitro. Galax seeds were collected from Yancey County, N.C., at an elevation of about 1100 m. Aseptic cultures were established using the tiny rust-colored seeds. In vitro seed germination was achieved under different pH conditions (4.2, 5.0, and 5.8). Seeds cultured in the medium with pH 4.2 tended to germinate early with a better rate than those cultured with a higher pH of 5.0 or 5.8 at the very beginning. Gradually, seeds from media with pH 5.0 and 5.8 caught up in germination. Eventually, seeds from all pH treatments produced a very similar germination rate. Attempts to use the matted and scaly rhizomes and very tender new growth as explant materials to establish aseptic cultures were not successful, due to severe contamination. However, our observations suggested that the very tender new growth could be a good source of explants once the optimum sterilization time is established.
A study was conducted with pansies (Viola wittrockiana) on a tobacco float bed system to determine if plugs could successfully be grown into transplants and to determine nutrient levels that wouldprovide the best transplants. Transplants were grown in a soilless media in 72-cell polystyrene float trays, floating on four different nutrient concentrations: 25, 50, 100, or 200 ppm. Length of time needed to produce regular-size transplants is reduced by half. Only 3 weeks are needed using the floating bed system, while 6 to 9 weeks are needed for the conventional method. Transplants displayed vigorous growth with normal morphology. Plant height and weight are significantly enhanced by increasing the nutrient concentration.
This research was initiated to study different culture media and plant growth regulators for their influences on callus initiation and production, with a research goal of developing an efficient in vitro callus regeneration protocol for guava (Psidium guajava L.). Guava is an important tropical fruit species that is rich in vitamins and vitamin precursors, minerals, organic acids, and pectins. Seventy-nine phytochemicals provide guava with many unique properties and actions, including anti-microbial, astringent, bactericidal, cicatrizant, emmenagogue, hypoglycemic, laxative, nutritive, and spasmolytic. Different concentrations of various plant growth regulators (PGR), such as 6-benzyladenine (BA), kinetin, or 2,4-dichlorophenoxyacetic acid (2,4-D), and naphthaleneacetic acid (NAA) were added to basic Murashige and Skoog (MS) and woody plant medium (WPM) and tested for their influences. Differences in callus initiation and morphology were noticed between MS and WPM, and among PGR concentration treatments.
Plug seedlings of Tagetes erecta L. `Gold Coin Mix' were planted in four production systems (harvest lugs, lay-flat bags, pots, and polystyrene trays) on 5 May 2005. Production systems were randomized in a Latin-square design with four replications of each system. Each treatment plot was 0.7 m × 1.1 m. Planting density was 31 plants/m2. The harvest lugs were 55 cm × 37 cm × 16 cm. The lay-flat bags were 114 cm × 30 cm × 3 cm. The pots were 25-cm bulb pans. The polystyrene trays were 67 × 34 × 5 cm and contained 32 square cells. All of the containers were filled with the same tobacco germination media. The plants in the harvest lugs, lay-flat bags, and pots were irrigated on alternate days with 150 mg·kg-1 N from 20N–4.4P–16.6K. The plants in the polystyrene trays were floated on a solution of 150 mg·kg-1 N from 20N–4.4P–16.6K. Float solutions were monitored and adjusted weekly for volume and fertilizer concentration. Individual stems were harvested at the appropriate stage of development for market. The fresh weight, stem length, and dry weight of individual stems were recorded. The rate of growth and maturation differed between production systems and locations in the greenhouse. Detailed results will be presented.
Plug seedlings of delphinium (Delphinium elatum L. `Guardian') were planted on 19 Nov. 2004 in four production systems (harvest lugs, lay-flat bags, pots, and polystyrene trays). Production systems were randomized in a Latin-square design with four replications of each system. Each treatment plot was 0.7 × 1.1 m. Planting density was 31 plants/m2. The harvest lugs were 55 × 37 × 16 cm. The lay-flat bags were 114 × 30 × 3 cm. The pots were 25 cm bulb pans. The polystyrene trays were 67 × 34 × 5 cm and contained 32 square cells. All of the containers were filled with the same tobacco germination media. The plants in the harvest lugs, lay-flat bags and pots were irrigated daily with 150 mg N/kg from 20N–4.4P–16.6K. The plants in the polystyrene trays were floated on a solution of 150 mg N/kg from 20N–4.4P–16.6K. Float solutions were monitored and adjusted weekly for volume and fertilizer concentration. Individual stems were harvested at the one-third bloom stage of development. The final harvest was on 1 Apr. 2005. Fewer stems were harvested from float trays and lay-flat bags than from pots and harvest lugs. The stems harvested from float tray plots were shorter than those from the other three systems. Stem fresh weight from greatest to least was lay-flat bags, harvest lugs, pots, and float trays. Stem dry weight was less for float trays than the other three systems.
This study investigated antimicrobial effects of guava products on the survival and growth of Escherichia coli O157:H7 in liquid medium. Seven strains of E. coli O157:H7 (944, 380, E0019, F4546, H1730, Cider, 9727) were tested. These strains were maintained in BHI broth. Guava fruits were sliced into small pieces and blended using a blender. Guava juice and leaves were then extracted using three solvents: water, methanol and hexane. Fruit extracts were dissolved in 10 ml BHI broth tubes to make a fruit solution of 5% (w/v). E. coli O157:H7 was inoculated into fruit solutions at 2 log cfu/mL. After incubation at 37 °C for 24 h, samples were serially diluted 10 folds. The proper diluent was spread-plated on TSA in duplicate. After incubation at 35 °C for 24 h, viable cell counts were obtained. The experiment was replicated three times in a randomized complete-block design. Results demonstrated that guava products (fruit, juice, and leaf extracts) significantly reduced survival and growth of the tested foodborne pathogen strains. Water extract showed the highest antimicrobial activity, followed by methanol and hexane. These results indicate guava extracts are a potential antimicrobial agent to ensure food safety.