Browsing by Author "Miller, Zachariah J."

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Bagging Apple Fruit for Codling Moth Control in Western Montana
(American Society for Horticultural Science, 2021-08) Leisso, Rachel S.; Jarrett, Bridgid; Mendrey, Katrina; Miller, Zachariah J.
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.
Climate Change Perceptions and Observations of Agricultural Stakeholders in the Northern Great Plains
(2018-05) Grimberg, Bruna; Ahmed, Selena; Ellis, Colter; Miller, Zachariah J.; Menalled, Fabian D.
Communities reliant on subsistence and small-scale production are typically more vulnerable than others to disasters such as earthquakes. We study the earthquakes that struck Nepal in the spring of 2015 to investigate their impacts on smallholder communities and the diverse trajectories of recovery at the household and community levels. We focus on the first year following the earthquakes because this is when households were still devastated, yet beginning to recover and adapt. Through survey questionnaires, focus group discussions, open-ended interviews, and observations at public meetings we analyze physical impacts to farming systems and cropping cycles. We investigate respondent reports of loss and recovery through a new social-ecological recovery assessment instrument and find that diversification of livelihoods and access to common resources, alongside robust community institutions, were critical components of coping and recovery. There was widespread damage to subsistence farming infrastructure, which potentially accelerated ongoing transitions to cash crop adoption. We also find that perceptions of recovery varied widely among and within the typical predictors of recovery, such as caste and farm size, in sometimes unexpected ways. Although postdisaster recovery has material and psychosocial dimensions, our work shows that these may not change in the same direction.
Cropping systems modify soil biota effects on wheat (Triticum aestivum) growth and competitive ability
(2017-02) Johnson, Stephen P.; Miller, Zachariah J.; Lehnhoff, Erik A.; Miller, Perry R.; Menalled, Fabian D.
Plants alter soil biota which subsequently modifies plant growth, plant-plant interactions and plant community dynamics. While much research has been conducted on the magnitude and importance of soil biota effects (SBEs) in natural systems, little is known in agro-ecosystems. We investigated whether agricultural management systems could affect SBEs impacts on crop growth and crop-weed competition. Utilising soil collected from eight paired farms, we evaluated the extent to which SBEs differed between conventional and organic farming systems. Soils were conditioned by growing two common annual weeds: Amaranthus retroflexus (redroot pigweed) or Avena fatua (wild oat). Soil biota effects were measured in wheat (Triticum aestivum) growth and crop-weed competition, with SBEs calculated as the natural log of plant biomass in pots inoculated with living soil divided by the plant biomass in pots inoculated with sterilised soil. SBEs were generally more positive when soil inoculum was collected from organic farms compared with conventional farms, suggesting that cropping systems modify the relative abundance of mutualistic and pathogenic organisms responsible for the observed SBEs. Also, as feedbacks became more positive, crop-weed competition decreased and facilitation increased. In annual cropping systems, SBEs can alter plant growth and crop-weed competition. By identifying the management practices that promote positive SBEs, producers can minimise the impacts of crop-weed competition and decrease their reliance on off-farm chemical and mechanical inputs to control weeds, enhancing agroecosystem sustainability.
First Report of Halyomorpha halys (Hemiptera: Pentatomidae) in Montana, USA
(Oxford University Press, 2022-01) Morey, Amy C; Kerzicnik, Lauren M; Etzler, Frank E; Mendrey, Katrina; Morey, Bruce D; Miller, Zachariah J.
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.
Fresh haskap berry postharvest quality characteristics and storage life
(Canadian Science Publishing, 2021-11) Leisso, Rachel S.; Jarrett, Bridgid; Richter, Rebecca; Miller, Zachariah J.
Haskap (Lonicera caerulea L.) is a relatively new berry crop in North America, and little research exists regarding its postharvest storage characteristics or storage life. Postharvest changes in berry quality, and principal factors limiting storage life at 1.1 °C and 95% relative humidity, were evaluated up to 14 days for three cultivars in 2019 and up to 28 days for six cultivars in 2020. Containerized berries were periodically assessed for soluble solids content (SSC), skin rupture force (SRF) (both 2019 and 2020) and flesh firmness, titratable acidity (TA), and Brix/acid ratio (B/A) (2020 only). External appearance was also evaluated both years, revealing berry shrivel as the primary factor negatively impacting visual appeal, followed distantly by low incidence of spoilage later in storage. All cultivars exhibited relatively constant postharvest SSC and decreasing SRF, flesh firmness, and TA (resulting in increasing B/A ratio). Postharvest quality differed slightly between years; relative SRF was consistent among cultivars while SSC was not. Some cultivars had a portion of shriveled berries at harvest, pointing to a need for cultivar-specific harvest indices. Mean days to slight shrivel for individual berries varied among cultivars evaluated, ranging from 7.5–21.9 d postharvest, with mean weight loss ranging from 1.2%–1.6% at this stage. Combined with group marketability estimates — set at a threshold of 10% severely shriveled berries — we estimate a storage life of 7–10 d for fresh haskaps. Additional research is needed to delineate maturation physiology and optimize harvest timing.
Haskap maturity stages and their influence on postharvest berry quality
(Canadian Science Publishing, 2022-06) Leisso, Rachel S.; Jarrett, Bridgid; Richter, Rebecca; Miller, Zachariah J.
Limited information is available regarding haskap berry maturity and corresponding postharvest characteristics. We assessed detached berry quality, respiration rate, and ethylene production at five stages of maturity and compared postharvest storage influence on berries harvested at half-blue and softening stages. Ethylene’s increase at successive stages suggests its involvement with berry maturation, but concomitant respiration does not support classifying haskap ripening as climacteric. Results indicate harvesting at the less mature half-blue stage is not recommended, as berries had lower fresh weight and inferior quality relative to those harvested at the softening stage, both at harvest and following 14 d storage.
Haskap Preharvest Fruit Drop and Stop-drop Treatment Testing
(American Society for Horticultural Science, 2021-12) Leisso, Rachel S.; Jarrett, Bridgid; Miller, Zachariah J.
Haskap (Lonicera caerulea), also known as honeyberry, is a relatively new fruit crop in North America. To date, most academic activity and research in North America involving haskap has focused on cultivar development and health benefits, with relatively few field experiments providing information to guide field planning and harvest management for the recently released cultivars. In 2020, we documented preharvest fruit drop (PHFD) rates for 15 haskap cultivars planted in a randomized block design at our research center in western Montana with the aim of preliminarily determining whether certain cultivars may be prone to this phenomenon. Additionally, we evaluated two plant growth regulators (PGRs) to reduce PHFD in two cultivars previously observed to have high rates of PHFD. Results suggest cultivar-specific variations in PHFD near berry maturation. Because haskap harvest indices are not well-defined and may be cultivar-specific, we share our 1-year study results as preliminary information and as a call for further research. Cultivars Aurora, Boreal Blizzard, Borealis, Indigo Gem, Kapu, and Tana all had PHFD rates less than 12% of yield, where yield is the weight of berries lost to PHFD plus marketable yield and marketable yield is fruit remaining on the shrub at harvest. Cultivars Chito, Kawai, and Taka had the highest rates of PHFD, although marketable yields were still relatively high, especially for Kawai. We note that ease of fruit detachment is an important consideration in mechanical harvest, and this characteristic could be advantageous if managed appropriately. The PGRs evaluated (1-napthaleneacetic acid and aminoethoxyvinylglycine) did not influence PHFD rates; however, our study was limited by the sample size and by the lack of information regarding haskap abscission physiology. In summary, the haskap cultivars evaluated exhibited variable PHFD rates in the year of the study, and further research is needed to understand haskap fruit maturation, harvest indices, and abscission.
Impact of Cropping Systems, Soil Inoculum, and Plant Species Identity on Soil Bacterial Community Structure
(2017-02) Ishaq, Suzanne L.; Johnson, Stephen P.; Miller, Zachariah J.; Lehnhoff, Erik A.; Olivo, Sarah K.; Yeoman, Carl J.; Menalled, Fabian D.
Farming practices affect the soil microbial community, which in turn impacts crop growth and crop-weed interactions. This study assessed the modification of soil bacterial community structure by organic or conventional cropping systems, weed species identity [Amaranthus retroflexus L. (redroot pigweed) or Avena fatua L. (wild oat)], and living or sterilized inoculum. Soil from eight paired USDA-certified organic and conventional farms in north-central Montana was used as living or autoclave-sterilized inoculant into steam-pasteurized potting soil, planted with Am. retroflexus or Av. fatua and grown for two consecutive 8-week periods to condition soil nutrients and biota. Subsequently, the V3-V4 regions of the microbial 16S rRNA gene were sequenced by Illumina MiSeq. Treatments clustered significantly, with living or sterilized inoculum being the strongest delineating factor, followed by organic or conventional cropping system, then individual farm. Living inoculum-treated soil had greater species richness and was more diverse than sterile inoculum-treated soil (observed OTUs, Chao, inverse Simpson, Shannon, P<0.001) and had more discriminant taxa delineating groups (linear discriminant analysis). Living inoculum soil contained more Chloroflexi and Acidobacteria, while the sterile inoculum soil had more Bacteroidetes, Firmicutes, Gemmatimonadetes, and Verrucomicrobia. Organically farmed inoculum-treated soil had greater species richness, more diversity (observed OTUs, Chao, Shannon, P<0.05), and more discriminant taxa than conventionally farmed inoculum-treated soil. Cyanobacteria were higher in pots growing Am. retroflexus, regardless of inoculum type, for three of the four organic farms. Results highlight the potential of cropping systems and species identity to modify soil bacterial communities, subsequently modifying plant growth and crop-weed competition.
Impact of species identity and phylogenetic relatedness on biologically-mediated plant-soil feedbacks in a low and a high intensity agroecosystem
(2014-12) Miller, Zachariah J.; Menalled, Fabian D.
Aims: Plant species-specific effects on soil biota and their impacts on subsequent plant growth, i.e. plant-soil feedbacks (PSFs, henceforth), are major drivers in natural systems but little is known about their role in agroecosystems. We investigated the presence and magnitude of PSFs in two contrasting agricultural settings and tested the importance of species identity and phylogenetic relationships in determining PSFs. Methods: We compared PSFs that developed from an intensified agricultural site and a nearby non-cultivated pasture. Four weed and seven crop species were grown in soil inoculated with either biologically active or sterilized soils from each system. Four crop response species were grown to estimate PSFs. Results: PSFs were species-specific. The identity of currently- and previously-planted species and their interactions explained over 80 % of the variation in feedbacks. Biota from the intensified agricultural site produced negative feedbacks in three of the four response species. Phylogenetic relationships partially explained PSFs. Conclusions: PSFs can alter crop growth and may be altered by agricultural practices. The species-specific effect to soil biota should be taken into account when assessing the extent to which crop and weed species could influence subsequent plant growth.
A Meta-analysis of Canada Thistle Cirsium arvense Management
(2018-07) Davis, Stacy C.; Mangold, Jane M.; Menalled, Fabian D.; Orloff, Noelle; Miller, Zachariah J.; Lehnhoff, Erik A.
Although stand-alone and integrated management techniques have been cited as viable approaches to managing Canada thistle [Cirsium arvense (L.) Scop.], it continues to impact annual cropping and perennial systems worldwide. We conducted meta-analyses assessing effectiveness of management techniques and herbicide mechanism of action groups for controlling C. arvense using 55 studies conducted in annual cropping systems and 45 studies in perennial systems. Herbicide was the most studied technique in both types of systems and was effective at reducing C. arvense. However, integrated multitactic techniques, with or without herbicides, were more effective than sole reliance on herbicides for long-term control in both annual cropping and perennial systems. A variety of management techniques such as biocontrol, crop diversification, mowing, and soil disturbance provided control similar to that of herbicide. Our results suggest that many management techniques aimed at reducing C. arvense can also improve crop yield or abundance of desired plants. This study highlights the need to devote more research to nonchemical and integrated management approaches for C. arvense control.
A Meta-Analysis of Field Bindweed Convolvulus arvensis Management in Annual and Perennial Systems
(2018-07) Davis, Stacy C.; Mangold, Jane M.; Menalled, Fabian D.; Orloff, Noelle; Miller, Zachariah J.; Lehnhoff, Erik A.
Field bindweed (Convolvulus arvensis L.) is a persistent, perennial weed species that infests a variety of temperate habitats around the globe. To evaluate the efficacy of general management approaches and impacts on crop yield and to identify research gaps, we conducted a series of meta-analyses using published studies focusing on C. arvensis management in annual cropping and perennial systems. Our analysis of 48 articles (560 data points) conducted in annual systems indicated that 95% of data points measured efficacy over short time frames (within 2 yr of treatment). Furthermore, only 27% of data points reported impacts of C. arvensis management on crop yield. In annual systems, herbicide control dominated the literature (~80% of data points) and was an effective management technique up to 2 yr posttreatment. Integrated management, with or without herbicides, and three nonchemical techniques were similarly effective as herbicide at reducing C. arvensis up to 2 yr posttreatment. In addition, integrated approaches, with or without herbicides, and two nonchemical techniques had positive effects on crop yield. There were few differences among herbicide mechanism of action groups on C. arvensis abundance in annual systems. There were only nine articles (28 data points) concerning C. arvensis management in perennial systems (e.g., pasture, rangeland, lawn), indicating more research effort has been directed toward annual systems. In perennial systems, biocontrol, herbicide, and non-herbicide integrated management techniques were equally effective at reducing C. arvensis, while competition and grazing were not effective. Overall, our results demonstrate that while chemical control of C. arvensis is generally effective and well studied, integrated and nonchemical control practices can perform equally well. We also documented the need for improved monitoring of the efficacy of management practices over longer time frames and including effects on desired vegetation to develop sustainable weed management programs.
Warm-Season Forage Options in Northern Dryland Regions
(2020-06) Carr, Patrick M.; Boss, Darrin L.; Chen, Chengci; Dafoe, Julia M.; Eberly, Jed O.; Fordyce, Simon; Hydner, Roger M.; Fryer, Heather K.; Lachowiec, Jennifer A.; Lamb, Peggy F.; McVay, Kent A.; Khan, Qasim A.; Miller, Perry R.; Miller, Zachariah J.; Torrion, Jessica A.
Rotating summer fallow with wheat (Triticum spp.) is done in dryland grain farming at upper latitudes to stabilize yields over time and to prevent crop failure. However, summer fallow is costly since weeds must be controlled and crops are not grown. Replacing summer fallow with grain crops can generate low economic returns. Previous research indicated that annual cool‐season forages can be substituted for summer fallow in dryland cropping systems. Our objective was to determine if annual warm‐season species were suited for forage production in monocultures and polycultures in the U.S. northern Great Plains. Dry matter (DM) production by 20 warm‐ and cool‐season crop monocultures and 4 polycultures was determined across six environments during 2016, and by 25 warm‐ and cool‐season crop monocultures and polycultures across four environments from 2016 through 2018. Maize (Zea mays L.) monoculture produced forage DM in amounts equal to, or greater than, those produced by other warm‐ and cool‐season crop treatments (P < 0.05). Maize DM production averaged 2.5 to 5.7 Mg ha−1, depending on the study and environment. Sorghum (Sorghum bicolor L.), foxtail millet [Setaria italica (L.) P. Beauv.] and sunflower (Helianthus annuus L.) also produced relatively large amounts of forage DM. Polycultures failed to produce more DM than monocultures consistently (P > 0.40). These results indicate that maize and other warm‐season crops are adapted for dryland forage production in cool regions at upper latitudes. Additional research is needed to determine the impacts of annual warm‐season forages on grain yield in a forage‐wheat crop sequence.