Because honey bees periodically collect water, guttation water from treated crops has been suggested as a potential exposure route to systemic pesticides. We reviewed studies that were published in the scientific literature since a previous review of the topic. We identified several studies that reported residue levels of pesticides in guttation water. However, few studies addressed guttation water as a potential exposure route to honey bees. In these studies, no significant effects on honey bee colony health or overwintering survival were observed when colonies were located within fields of treated crops during guttation periods. The previous and current review suggests that exposure to pesticides via guttation water alone is unlikely to negatively affect honey bee colonies. A better understanding of water foraging by honey bees would be needed to address whether guttation water could represent a relevant exposure route of honey bees to systemic pesticides. guttation / honey bees / pesticide risk assessment / neonicotinoids

The goal of this study was to determine the co-occurrence between acetochlor use on crops and potentially vulnerable soils in the Permanent Interstate Committee for Drought Control in the Sahel region of Western Africa. Acetochlor, a pre-emergence herbicide, is used primarily on row crops and has the potential to reach groundwater or surface water following a rain event shortly after application. Off-field transport is often determined by soil properties; therefore, soils within potential use areas were assessed and mapped to establish areas with soils vulnerable to leaching and/or runoff. Corn and cotton production areas were used as surrogate crops for high potential use areas of acetochlor within areas identified using GlobCover land use data and the Spatial Production Allocation Model agricultural statistics data. The geospatial analysis identified approximately 462 million ha of potentially vulnerable soils in the Sahel region of which 65.7 million ha are within agricultural areas. An adjustment for corn and cotton production areas showed that 2.2 million ha or 3.3% of agricultural fields could have potential restrictions for acetochlor use. Approximately 0.159 million ha of soils or 0.24% of agricultural fields are in the presence of shallow groundwater, defined by depth < 9 m. In addition, 0.0128 million ha or 0.02% were determined to be adjacent to surface water bodies. To understand the uncertainty associated with the use of specific land cover datasets, an overlay assessment was conducted using alternative data sources. Overlap between selected land cover datasets in the Sahel region varies and ranges from 24.7% to 75.5% based on a merged 2009 GlobCover and CCI LC datasets. In comparison with the merged 2005 and 2009 GlobCover dataset, the cropland overlaps range from 38.9% to 85.0%. This demonstrates that the choice of land cover dataset can have a significant impact on a spatial assessment. Results from this assessment demonstrate that only a small fraction of vulnerable agricultural soils across the region may be a risk for contamination by acetochlor of groundwater or surface resources, based on product label

The potential impact of elevated atmospheric carbon dioxide concentration ([CO2]) and future climate predicted for 2050 on wheat marketing grades and grain value was evaluated for Victoria, Australia. This evaluation was based on measured grain yield and quality from the Australian Grains FACE program and commercial grain delivery data from Victoria for five seasons (2009–13). Extrapolation of relationships derived from field experimentation under elevated [CO2] to the Victorian wheat crop indicated that 34% of grain would be downgraded by one marketing grade (range 1–62% depending on season and region) because of reduced protein concentration; and that proportions of high-protein wheat grades would reduce and proportions of lower protein grades would increase, with the largest increase in the Australian Standard White (ASW1) grade. Simulation modelling with predicted 2050 [CO2] and future climate indicated reduced wheat yields compared with 2009–13 but higher and lower grain quality depending on region. The Mallee Region was most negatively affected by climate change, with a predicted 43% yield reduction and 43% of grain downgraded by one marketing grade. Using 2016 prices, the value of Victorian wheat grain was influenced mainly by production in the different scenarios, with quality changes in different scenarios having minimal impact on grain value.

The objective of the investigation was to determine whether microwave fields would enhance the reactions of CO 2 with silicates that are relevant to the sequestration of carbon dioxide. Three sets of experiments were conducted. (1) Serpentine and CO 2 were reacted directly at one atmosphere pressure in a microwave furnace. Little reaction was observed. (2) Serpentine was dehydroxylated in a microwave furnace. The reaction was rapid, reaching completion in less than 30 minutes. A detailed investigation of this reaction produced an S-shaped kinetics curve, similar to the kinetics from dehydroxylating serpentine in a resistance furnace, but offset to 100 ˚C lower temperature. This set of experiments clearly demonstrates the effect of microwaves for enhancing reaction kinetics. (3) Reactions of serpentine with alkaline carbonates and in acid solution were carried out in a microwave hydrothermal apparatus. There was a greatly enhanced decomposition of the serpentine in acid solution but, at the temperature and pressure of the reaction chamber (15 bars; 200 ˚C) the carbonates did not react. Overall, microwave fields, as expected, enhance silicate reaction kinetics, but higher CO 2 pressures are needed to accomplish the desired sequestration reactions. These reactions are thermodynamically favorable but suffer from exceeding slow reaction rates. Research by others has shown that reaction rates can be accelerated by use of aqueous carbonate solutions and high CO 2 pressures. The proposed research offers an alternative rate enhancement mechanism through the use of microwave fields. Scope of Work and Task ListThe Scope of Work and list of tasks are taken directly from the original proposal. Progress and accomplishments on the tasks are then summarized in the sections that follow.Two series of experiments were proposed. In series (1) a gas stream of CO 2 containing variable amounts of water vapor would be reacted directly with the magnesium silicates at modest temperatures in a microwave cavity. The objective would be to determine the rate of reaction as a function of temperature, water vapor partial pressure, magnesium silicate particle size, and microwave power. In series (2) experiments, aqueous solutions would be reacted with CO 2 under pressures up to 80 bars and temperatures up to 200 C in a Teflon high pressure reactor in a microwave field. One objective of this portion of the research would be to compare the efficacy of microwave processing with similar compositions, temperatures and pressures without microwaves. Task 1. Adapt existing microwave equipment for continuous gas stream reaction.Task 2. React magnesium silicates with wet CO 2 at a sequence of water contents, temperatures, and microwave power levels.Task 3. Characterize products from Task 2 experiments and determine rates of reaction.Task 4. Construct equipment for microwave hydrothermal experiments.Task 5. React silicates in aqueous alkali carbonate solutions at autogeneous steam pressures in the microwave field.Task 6. React silicates in aqueous...

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