Search Results
Abstract
Selected physical and chemical properties of pine bark, 2 sources of coal cinders, and mixtures thereof, were evaluated as container media components. Bulk density, air-filled pore space, particle-size distribution, cation exchange capacity, and soluble salt levels were quantified. Aged and freshly combusted cinders demonstrated no major physical or chemical disadvantages when used in container media. Acid and water extracts indicated that both sources of coal cinders released significant amounts of micronutrients and heavy metals. The concentrations of certain metals were sufficiently high to warrant concern over the possibility of plant nutritional disorders; whereas, other released elements resembled those of a supplemental micronutrient fertilizer.
Abstract
Thirteen species of woody ornamentals were treated over-the-top with glyphosate in a 6 × 6, rate by time factorial experiment. The influence of application timing on glyphosate phytotoxicity was significant for all species. The times of maximum tolerance and injury were species dependent. Species were organized into 4 response groups based on the effects of application time. Group 1 species, including ajuga (Ajuga reptans L.), azalea (Rhododendron obtusum Planch. ‘Coral Bells’), and a variegated liriope (Liriope muscari L.H. Bailey), were injured on all application dates. Species in groups 2, 3, and 4 exhibited tolerance to fall applications of glyphosate. Group 2, including wax leaf privet (Ligustrum japonicum Thunb.), sustained maximal injury from spring applications. Group 3 species, including Compacta holly (Ilex crenata Thunb. ‘Compacta’), were injured most by summer applications of glyphosate. However, Blue Rug juniper (Juniperus horizontalis Moench ‘Wiltonii’), a representative of group 4, was tolerant of glyphosate applications, sustaining only temporary tip chlorosis from spring and early summer treatments. First season evaluations were not sufficient to describe the ultimate effects of glyphosate on plant quality. Visual and objective evaluations in the 2nd growth season also were necessary. Chemical name used: N-(phosphonomethyl) glycine (glyphosate).
Abstract
Coal cinders with pine bark were evaluated as containerized plant growing medium. Rhododendron obtusum Lindl. ‘Hinodegiri’ liners were grown in several combinations of media composed of pine bark mixed with an aged and a recently combusted source of cinders. Measurements of media pH, soluble salts, NO3 − –N, NH4 + –N, and 19 extractable nutrient and metallic ions were obtained. Leaf tissue samples were analyzed for 19 elements. Top dry weight, visual growth and chlorosis ratings, and root visual ratings constituted the plant growth parameters measured. Satisfactory growth was generated in pine bark amended with up to 50% cinders from either source.
A cooperative project between the Univ. of Florida Cooperative Extension Service, USDA Natural Resources Conservation Service, and Consolidated Farm Services Agency to address farm nutrient use and water management in the Lake Apopka hydrologic unit area of Florida began in 1991. This area was selected due to the vegetable production on the organic soils (muck) and sandy soils north of Lake Apopka, Florida's most polluted large lake. Discharge of nutrient-laden water into the lake from the 4050-ha vegetable production area has been implicated as a major contribution to the hypereutrophic status of the lake. Changes in cultural practices including water management, which would lead to a reduction in nutrient loading, should aid in the restoration of the lake. A grower survey of fertilizer application rates was conducted each year for 4 years with the baseline established by the 1991 survey. Demonstration plots using soil tests as the basis for fertilizer rates compared to normal grower rates of fertilizer were established for carrots, sweet corn, and celery. In 1995, muck growers had reduced their total application of N by 16%, P 52%, and K 32%, without reducing yields or quality. Nutrient applications were reduced by over 656 t/year over the years surveyed. Farms have saved fertilizer and reduced environmental risks.
Three, 2-day hands-on experiential learning workshops were presented in three southeastern United States cities in June 2014, by the Southern Nursery Integrated Pest Management (SNIPM) working group. Attendees were provided 4 hours of instruction including hands-on demonstrations in horticultural management, arthropods, plant diseases, and weeds. Participants completed initial surveys for gains in knowledge, skills, and abilities as well as their intentions to adopt various integrated pest management (IPM) practices after the workshop. After 3 years, participants were again surveyed to determine practice adoption. Respondents changed their IPM practice behavior because of attending the workshops. Those returning the survey set aside more time to scout deliberately for pests, plant diseases, and weeds; used a standardized sampling plan when scouting; and adopted more sanitation practices to prevent plant disease. Fewer horticultural management practices were adopted than respondents originally intended. Future emphasis should be placed on using monitoring techniques to estimate pest emergence, for example, traps and pheromone lures, as well as plant phenology and record keeping. However, more work is needed to highlight both the immediate and long-term economic benefits of IPM practice adoption in southeastern U.S. nursery production.