A replicated column trial was conducted to evaluate the potential for the phosphorus saturation index (PSI) to predict P movement in bioretention soil mixtures (BSMs). The impact of compost feedstock on BSM performance was also evaluated. Three composts (biosolids/yard, yard/food waste, and manure/sawdust) were each brought to PSI values of 0.1, 0.5, and 1.0 through the addition of Fe-based water treatment residuals (WTRs) to lower the PSI and P salts to increase the PSI. A synthetic stormwater solution was used for 12 leaching events. The PSI predicted total and dissolved P concentrations in column leachate. All composts removed P at PSI 0.1. All composts were a source of P for the higher PSI values tested, with P concentrations in the leachate decreasing over time. Ammonia and nitrate from all treatments decreased over time, with all treatments showing effective N removal. Copper removal (total and dissolved) was >90% for all treatments, with the highest removal observed at PSI 0.1 for all composts. Zinc removal (total) was also greatest in the 0.1 PSI for all composts. At PSI 0.5 and 1.0, the biosolids/yard compost was less effective than the other materials at removing Zn, with a removal efficiency of approximately 50%. Infiltration rates were similar across all treatments and ranged from 0.44 ± 0.1 cm min in the manure/sawdust at PSI 0.1 to 3.8 ± 2.8 cm min in the food/yard at PSI 1.0. Plant growth in the manure/sawdust compost was reduced in comparison to the other composts tested across all PSI levels. The results of this study indicate that the PSI may be an effective tool for predicting P movement in bioretention systems. Compost feedstock does not indicate the ability of composts to filter contaminants filtration, with all composts tested showing high contaminant removal.

Codling moth (Cydia pomonella) is a major insect pest of apple (Malus domestica). If unmanaged, then codling moth can infest nearly all apples in an orchard, where the flesh-tunneling larva leave frass-laden tracks in the fruit. Insecticide-based management requires accurate application timing (typically based on adult moth and/or degree-day monitoring) and multiple spray applications. Both the season-long commitment to codling moth monitoring and management and limited familiarity with insecticides, application tools, and proper application procedures can prevent a small-scale or backyard grower from effectively limiting fruit damage. In addition, an increasing segment of growers is interested in nonchemical alternatives. Bagging fruitlets early in the season could be a simple and effective method of codling moth management for this subset of growers. At our research orchard in Corvallis, MT, we tested a method combining fruit thinning and bagging using plastic bags the first season and nylon bags the second season. Plastic bags reduced the incidence of codling moth damage to fruit from 34% to 10%, but european earwig (Forficula auricularia) frass, which was found in more than 50% of plastic-bagged apples, made harvesting the fruit unappealing. We tested nylon fruit bags during the second year of the study. These bags did not significantly reduce the incidence of codling moth. Both the soluble solids content and titratable acidity were higher in unbagged fruit during the second year of the study, whereas color measurements indicated bagged fruit were greener on the shaded side of the fruit. Failure of the nylon bags may have been attributable to eggs laid before bagging, eggs laid or larva burrowing through bagging, or improper bag application methods. Further research could assess whole-tree bags, the addition of rubber bands or twist ties when applying nylon bags, pretreatment of fruit with horticulture oil, and/or dipping nylon bags in kaolin clay before application; however, these steps add time and increase costs, which may discourage the small-scale fruit grower. Overall, results indicate that fruit bagging holds promise for codling moth management; however, further work is needed to optimize the methodology.

Here, we document the first record for Montana of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), a major agricultural and nuisance pest in many parts of the world. The insect was found overwintering in a private residence in January 2021 in Billings (Yellowstone Co.). A preliminary survey of sites in Billings from May to October 2021 confirmed the presence of H. halys within a radius of at least 11 km from the January detection. Putatively overwintering H. halys and adult bugs found across the city of Billings in the summer suggest the insect may have been present in the area prior to 2021. Surveys conducted in various regions of the state between 2013 and 2020 reported no detections of H. halys. Yellowstone Co. was previously surveyed in 2017, indicating the species likely arrived between 2018 and 2020 or was present before 2018 at densities too low to be detected. The summary of presence and absence records we provide herein is valuable for future monitoring and management efforts of this economically important species.

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