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.

Broadening Participation in Scientific Conferences during the Era of Social Distancing.

Virtual conferences can offer significant benefits but require considerable planning and creativity to be successful. Here we describe the successes and failures of a hybrid in-person/virtual conference model. The COVID-19 epidemic presents the scientific community with an opportunity to pioneer novel models that effectively engage virtual participants to advance conference goals.

Temperature Impacts on Soil Microbial Communities and Potential Implications for the Biodegradation of Turfgrass Pesticides.

Maintaining healthy turfgrass often results in the use of pesticides to manage weed, insect, and disease pests. To identify and understand potential nontarget impacts of pesticide usage while still maintaining attractive and functional turfgrass sites, it is important to improve our understanding of how pesticides degrade in various environments throughout the growing season. Temperature heavily influences microbial community composition and activity, and the microbial community often heavily influences pesticide degradation in soil ecosystems. Pesticide transformation products generated through the action of soil microbial degradation networks can vary in their toxicity, with the potential result that a pesticide applied in the spring at 10°C could produce different transformation products with different toxicological impacts than the sample pesticide applied to the same site at 22°C. The objective of this review is to examine past research surrounding soil microbial activity related to pesticide degradation and provide a foundation for how the soil microbiome interacts with pesticides and how seasonal temperature variations may influence those interactions.