Dollar Spot Suppression on Creeping Bentgrass in Response to Repeated Foliar Nitrogen Applications.

Dollar spot is caused by the fungus Clarireedia spp. and is the most economically important disease of golf course turfgrass in temperate regions of the United States. Previous research has demonstrated that nitrogen (N) fertilization may reduce dollar spot severity, but the results have been inconsistent, and the impact of N as part of repeated foliar fertilization applications to golf course putting greens remains unclear. Two independent trials were replicated in Madison, Wisconsin and Glenview, Illinois in the 2015, 2016, and 2017 growing seasons. The objective of the first trial was to evaluate the effect of four different N rates applied as urea (4.9, 9.8, 19.4, and 29.3 kg N/ha applied every 2 weeks) on dollar spot severity, and the objective of the second trial was to evaluate the effect of three N sources (calcium nitrate, ammonium sulfate, and ammonium nitrate applied every 2 weeks) on dollar spot severity. Results from the N rate trial at both locations indicated that only the highest (29.3 kg N/ha) rate consistently reduced dollar spot severity relative to the nontreated control. Nitrogen source had minimal and inconsistent impacts on dollar spot severity based on location and year. Although these results show that meaningful reductions in dollar spot severity can be achieved by manipulating N fertilizer application rates, the rate of N needed for disease suppression may be impractical for most superintendents to apply and result in undesirable nontarget impacts.

Using Community-Based Participatory Research to Explore Backyard Gardening Practices and Soil Lead Concentrations in Urban Neighborhoods.

BACKGROUND: Lead exposure is a serious health threat for children. Soil is an important exposure pathway, primarily through ingestion and inhalation. Urban agriculture is increasing. Potential environmental health risks associated with residential gardening may not be well known to community residents. OBJECTIVES: A community-based participatory research (CBPR) approach was implemented to explore the relationship between urban residential vegetable gardening and lead exposure in children. The primary objectives were to characterize local backyard vegetable gardening practices, measure residential and commercial soil lead concentrations and spatial distributions, and identify priorities for individual and collective action. METHODS: Participants were recruited in two stages. In phase 1, adult gardeners participated in structured interviews. In phase 2, a multistage representative sampling approach was implemented to recruit adult gardeners for interviews and soil testing. RESULTS: Twenty adults participated in gardening practice interviews. Adults perceive many benefits from backyard gardening and initially expressed few concerns about lead exposure risk. Results indicate that children are actively involved in backyard gardening. Total soil lead concentrations from 17 residential properties ranged from 7 to 3,234 mg kg-1(median, 187; mean, 432). Commercial soils had lead concentrations that ranged from 6 to 13 mg kg(-1) (median, 6.5; mean, 7.6). Nonparametric Mann-Whitney comparisons indicated a significant difference in lead concentration between commercial soil and residential soil (p<0.0001). CONCLUSIONS: Advocacy for resources needed to eliminate dangerous levels of lead from the environment, especially in communities where divestment has occurred, is enhanced through CBPR. Increasing access to soil testing is an important action step.