Weed Emergence Patterns in Response to Disturbance on Two Soil Types

NYS IPM Type: Project ReportWeeds are a major constraint to crop production in NY State and can significantly reduce the quantity and quality of harvested crops. The management of weeds also incurs substantial costs for farmers and may have negative impacts on the environment. Thus, there is an urgent need to better predict the timing of weed emergence in cropping systems and to identify those factors affecting emergence. In this research, we studied the emergence pattern of agricultural weeds in two common central NY soil types and in response to biweekly soil disturbance. Seedling emergence data and weather data (i.e. growing-degree days and precipitation) were collected at two research locations in central NY throughout the 2016 growing season. The Musgrave Research Farm (Aurora, Cayuga County, NY) has moderately drained clay-loam soils (Honeyoe/Lima soils) where grain crops are studied, while the Homer Thompson Research Farm (Freeville, Tompkins County, NY) is on very well-drained sandy loam (Howard/Phelps soils) where both vegetable and grain crops are grown. The 2016 growing season was exceptionally dry; weed emergence rates were low at both sites, but emergence was lowest at the H. Thompson site in the better-drained soils despite similar rainfall and temperatures. Data from ten weed species were analyzed; of these, only pigweed (Amaranthus spp.) was common at both sites. At the Musgrave site, weed emergence for all species peaked in late May/early June, with a smaller flush in late summer; the exception was Venice mallow (Hibiscus trionum), which had its main emergence in mid-summer. At both sites, warm- and cool-season weeds were present, as well as an annual grass; but emergence patterns were more varied. The perennial grass Kentucky bluegrass (Poa pratensis) emerged only in the spring, while hairy galinsoga (Galinsoga quadriradiata) and common chickweed (Stellaria media) emerged mainly in the fall with a small preliminary flush in June; common chickweed had similar emergence rates in June and September. At both sites, repeated cultivation stimulated emergence during mid-season with the exception of foxtails (Setaria spp.) at Musgrave, where emergence was higher mid-season in the undisturbed soil treatment

Comparative Study of \u3ci\u3eMecinus Janthiniformis\u3c/i\u3e (Coleoptera: Curculionidae) Attack and Simulated Mowing for Control of \u3ci\u3eLinaria Dalmatica\u3c/i\u3e Spp. \u3ci\u3eDalmatica\u3c/i\u3e (Plantaginaceae)

Dalmatian toadflax, Linaria dalmatica spp. dalmatica (L.) Mill. (Plantaginaceae) has invaded over one million hectares in the western United States and Canada, in habitats similar to its native range. Two field studies were conducted to examine the impact of simulated mowing or insect herbivory on L. dalmatica growth and reproduction. Simulated mowing over the duration of the study decreased L. dalmatica total biomass per square meter, significantly reduced the total number of fruits and flowers per square meter, and resulted in significantly shorter flowering stems in the simulated mowing plots than in their controls. Plants in plots attacked by Mecinus janthiniformis Toševski and Caldara (Coleoptera: Curculionidae) had significantly less biomass per square meter, significantly fewer total numbers of fruits and flowers per square meter, and significantly fewer reproductive structures per stem than plants in paired control plots over the duration of the study. Specifically, both management tactics resulted in a negative impact on this invasive plant. With repeated tissue removal or damage, a reduction in numbers of fruits and flowers per stem on both the stems subjected to simulated mowing and Mecinus-attacked stems relative to their controls suggests that long term stress effects on the plants may be similar. The results of these studies suggest that mowing may warrant further evaluation as a possible method of control in areas where M. janthiniformis release is not effective

Biological Control of Ground Ivy Using a Rust Fungus

Ground-ivy or creeping Charlie (Glechoma hederacea) is a creeping perennial in the Mint Family that forms dense prostrate patches in turfgrass, damp shady meadows, and disturbed sites. The control of ground ivy using chemical and mechanical methods has largely been unsuccessful in turfgrass where it is considered a major weed. Thus, there is a pressing need to develop and evaluate alternative approaches for the control of ground ivy in turfgrass that are effective and environmentally sound

Impact of \u3ci\u3eMecinus Janthinus\u3c/i\u3e (Coleoptera: Curculionidae) on the Growth and Reproduction of \u3ci\u3eLinaria Dalmatica\u3c/i\u3e (Scrophulariaceae)

Dalmatian toadflax, Linaria dalmatica (L.) Mill. (Scrophulariaceae), a native to the eastern Mediterranean and Black Sea regions of Europe and Asia, has invaded over one million hectares in the western United States and Canada, in habitats similar to its native range. Once established, the aggressive vegetative growth of the plant allows it to invade undisturbed habitats where it can out-compete most other vegetation, placing native plant communities at risk. Biological control of L. dalmatica with Mecinus janthinus Thomson (Coleoptera: Curculionidae) has shown promise in the field. In both studies reported in this paper, the presence of insect attack reduced L. dalmatica plant growth and reduced plant reproductive potential. In a field sleeve cage study, insect- attacked stems were significantly shorter (18 cm) and had 50-70% fewer fruits and flowers than the control stems at the end of the study period. M. janthinus attacked stems showed little apical growth, fewer fruits and flowers, and lower stem biomass relative to control stems. Similar results were observed in the potted plant study where the influence of the extensive root system of the plant was eliminated. This negative impact by the insect is caused both by adult feeding in the apical portion of the plant and the physical destruction of the plant stem from larvae feeding. The decrease in the insect-attacked stem heights may also have an impact on seed dispersal from the mature reproductive structures. A combination of decreased seed production through M. janthinus biological control and poor seedling competition in the moisture limited sites common to north-central Washington State and other similarly dry habitats may negatively influence L. dalmatica populations more than general models predict

Implementation of virtual workflows in KNIME for medicinal chemistry

This project demonstrates how two programs are created in KNIME - an open source data analytic, reporting and integration platform, are used to support research scientists in medicinal chemistry. The first application flags pan-assay interference compounds such as “promiscuous” compounds present in chemical libraries that recurrently behaves as false positive hits in screening campaigns. The second application adapted a previously published workflow, where it automatically scans the recently published scientific literature on a weekly basis, and identifies articles considered relevant to medicinal chemists focused on epigenetic mechanisms, a novel and promising field in drug discovery. These workflows are very important because they allow a user with relatively little training to be able to extract important data that would typically need a trained chemist for. The PAINS workflow performed adequately but data was problematic. This workflow and an online tool, used to compare results, agged different, but overlapping sets of compounds. The PubMed alert workflow performed very well, being able to consistently identify new papers. These workflows have been implemented at the Structural Genomics Consortium, in Toronto. Both Workflows are available at http://sgc.utoronto.ca/ditommaso.zip The implementation of these workflows demonstrate that the process is viable, and paves the way for the implementation of more complex workflows. Ce projet montre comment deux logiciels qui ont été créés en utilisant KNIME - une plate-forme open-source d’intégration et de reportage de data analytique, sont utilisées comme soutient pour les chercheurs dans le domaine de chimie médicale. La première application signale les composés d’interférence pan-essai (PAINS), par exemples des composés ‘libérés’ présents dans les chimiothèques, qui s’agissent souvent comme des fausses réactions positives pendant les campagnes de dépistage. La deuxième application, le système de workflow PubMed alert, a adapté un système de workflow développé auparavant qui parcourt rapidement la littérature scientifique publiée récemment une fois par semaine et identifie des articles qui sont pertinents pour des chimistes médicales qui étudient des mécaniques épigénétiques, un domaine novateur et prometteur dans les découvertes des drogues. Ces systèmes de workflow sont très importants car ils permettent un utilisateur avec relativement peu d’entraînement à soutirer des données importantes qui ont typiquement besoin d’être trouvées par les chimistes entraînés. Le système de workflow de PAINS a fonctionné suffisamment mais les données trouvées étaient problématiques. Le système et un outil en ligne utilisé pour la comparaison des résultats ont signalés des résultats différents, mais les résultats se sont débordés sur les unes les autres. Nous avons trouvés que le système de workflow PubMed alert a très bien fonctionné, car le système pouvait constamment identifier des nouveaux papiers scientifiques. Ces systèmes de workflow sont maintenant implémentés au Consortium Génomique Structurel (SGC) à Toronto. Les deux systèmes de workflow sont disponibles à http://sgc.utoronto.ca/ditommaso.zip. L’implémentation de ces systèmes de workflow montre que le procès est viable et ouvre la voie pour l’implémention des systèmes de workflow plus complexes.

Planting date effects on the germinability and seedling vigour of Abutilon theophrasti (Malvaceae) seeds

Abutilon theophrasti (Malvaceae) is a troublesome annual weed in many maize and soybean cropping systems of Canada and the United States. Seeds of A. theophrasti exhibit physical dormancy. Differences in the growing environment of parent plants may influence the germinability of seeds and vigour of seedlings produced by this species because of variation in resource allocation to seed development. Thus, the germinability of seeds and subsequent seedling vigour were examined for A. theophrasti plants grown in monoculture at a density of 4.2 plants m-2 under varying natural photoperiods in central New York State. Treatments were established by transplanting A. theophrasti seedlings on three dates: 15 May, 4 June, and 30 June 2000, which correspond to peak photoperiods of 15, 14, and 13 hours, respectively. Seeds produced under the shorter photoperiod (13 h) weighed, on average, 1.5 mg less than seeds produced under the longer photoperiod (15 h). Contrary to expectations, seeds of A. theophrasti that matured under shorter photoperiods had lower germinability (80%) than seeds produced under longer photoperiods (98%). Early radicle growth, a measure of seedling vigour, did not differ between the photoperiod treatments. Environmental conditions other than photoperiod (i.e. water availability) prevailing during the 2000-growing season may have influenced seed coat thickness and consequently affected the germinability of seeds.L’Abutilon theophrasti (Malvaceae) est une mauvaise herbe annuelle qui gêne la production du maïs et du soja dans plusieurs systèmes de culture du Canada et des États-Unis. Les graines de l’A. theophrasti possèdent une dormance physique. Des différences de l’environnement dans lequel croissent les plantes mères peuvent influencer la germination des graines et la vitalité des plantules de cette espèce à cause de variations dans l’affectation des ressources avant que les graines soient pleinement développées. Ainsi, la germination des graines et la vitalité des plantules qui en sont issues ont été étudiées pour l’A. theophrasti en monoculture à une densité de 4,2 plantes m-2 sous diverses photopériodes naturelles du centre de l’État de New York. Les traitements ont débuté par la plantation de plantules de l’A. theophrasti à trois dates, 15 mai, 6 juin et 30 juin 2000, qui correspondent respectivement à des photopériodes maximales de 15, 14 et 13 heures. Les graines produites avec la photopériode la plus courte (13 h) pesaient en moyenne 1,5 mg de moins que les graines produites avec les plus longues photopériodes (15 h). Contrairement à ce qui était prévu, les graines de l’A. theophrasti qui se sont formées lors des photopériodes les plus courtes avaient une germination plus faible (80 %) que les graines formées lors des photopériodes les plus longues (98 %). La croissance précoce de la radicule, une mesure de la vitalité des plantules, est restée la même pour les différentes photopériodes. Les conditions environnementales autres que la photopériode (c.-à-d. la disponibilité en eau) qui régnaient au cours de la saison de croissance de 2000 peuvent avoir influencé l’épaisseur du tégument et avoir ainsi eu un effet sur la germination des graines

Comparative Study of \u3ci\u3eMecinus Janthiniformis\u3c/i\u3e (Coleoptera: Curculionidae) Attack and Simulated Mowing for Control of \u3ci\u3eLinaria Dalmatica\u3c/i\u3e Spp. \u3ci\u3eDalmatica\u3c/i\u3e (Plantaginaceae)

Dalmatian toadflax, Linaria dalmatica spp. dalmatica (L.) Mill. (Plantaginaceae) has invaded over one million hectares in the western United States and Canada, in habitats similar to its native range. Two field studies were conducted to examine the impact of simulated mowing or insect herbivory on L. dalmatica growth and reproduction. Simulated mowing over the duration of the study decreased L. dalmatica total biomass per square meter, significantly reduced the total number of fruits and flowers per square meter, and resulted in significantly shorter flowering stems in the simulated mowing plots than in their controls. Plants in plots attacked by Mecinus janthiniformis Toševski and Caldara (Coleoptera: Curculionidae) had significantly less biomass per square meter, significantly fewer total numbers of fruits and flowers per square meter, and significantly fewer reproductive structures per stem than plants in paired control plots over the duration of the study. Specifically, both management tactics resulted in a negative impact on this invasive plant. With repeated tissue removal or damage, a reduction in numbers of fruits and flowers per stem on both the stems subjected to simulated mowing and Mecinus-attacked stems relative to their controls suggests that long term stress effects on the plants may be similar. The results of these studies suggest that mowing may warrant further evaluation as a possible method of control in areas where M. janthiniformis release is not effective

Climate Dynamics, Invader Fitness, and Ecosystem Resistance in an Invasion-Factor Framework

As researchers and land managers increasingly seek to understand plant invasions and the external (climate) and internal (plant genetics) conditions that govern the process, new insight is helping to answer the elusive question of what makes some invasions successful and others not. Plant invasion success or failure is based on a combination of evolutionary and ecological processes. Abiotic (e.g., climate) and biotic (e.g., plant competition) conditions in the environment and plant genetics (e.g., fitness) combine in either decreasing or increasing invasion, yet it has proven challenging to know exactly which of these conditions leads to success for a given species, even when a wealth of empirical data is available. Further, current regional distribution models for invasive plant species rarely consider biotic and fitness interactions, instead focusing primarily on abiotic conditions. The crucial role of all three factors (climate dynamics, invader fitness, and ecosystem resistance) must not be ignored. Here we construct a three-factor invasion framework from which we develop conceptual models using empirical studies for yellow starthistle, nonnative common reed, and musk thistle, three dissimilar but commonly occurring invasive plant species in North America. We identify how components of the invasion process—rapid population increase, established local dominance, and rapid range expansion—are influenced by ecosystem resistance, invader fitness, and/or climate dynamics, a set of broadly defined factors for each of the three invasive plant species. Our framework can be used to (1) establish research priorities, (2) address gaps in theoretical understanding, and (3) identify invasion process components that can be targeted to improve management. Building on previous models, our unifying framework, which can be used for assessing any invasive plant species having sufficient empirical data, simultaneously shows the influence of ecosystem resistance, invader fitness, and climate dynamics factors on the invasion process. Nomenclature: Common reed, Phragmites australis (Cav.) Trin. ex Steud.; musk thistle, Carduus nutans L.; yellow starthistle, Centaurea solstitialis L

Oviposition preference and larval performance of monarch butterflies (Danaus plexippus) on two invasive swallow-wort species

Abstract The potential of two invasive herbaceous vines Vincetoxicum nigrum (L.) Moench and Vincetoxicum rossicum (Kleopow) Barbar. (Asclepiadaceae) to reduce monarch butterfly ( Danaus plexippus L.) (Lepidoptera: Nymphalidae, Danainae) populations was investigated by evaluating oviposition selection in adult monarch butterflies and larval feeding preference in choice tests comparing the native host plant of monarch butterflies, Asclepias syriaca L. (Asclepiadaceae) and the two non-indigenous Vincetoxicum species. In both choice and no-choice tests, no eggs were oviposited on either of the two Vincetoxicum species whereas over 66 eggs per female were oviposited on A. syriaca plants. All first instar larvae allowed to feed on A. syriaca for 48 h survived while a significantly lower proportion survived on V. rossicum (44%) and V. nigrum (14%). Mean weight of larvae that did survive on the Vincetoxicum species was significantly lower than the mean weight of larvae that fed on A. syriaca . The mean weight of surviving larvae, however, did not differ between the two Vincetoxicum species. The mean proportion of leaves consumed by larvae feeding on A. syriaca was significantly greater than the mean proportion of leaves consumed by larvae feeding on either Vincetoxicum species. Findings from this research indicate that V. rossicum and V. nigrum are not viable hosts of monarch butterflies and are likely to pose little direct threat to their populations as oviposition sinks. The ability of these highly aggressive plants, however, to out-compete and displace the native host of monarchs, A. syriaca , may pose a more serious threat. The potential of monarch populations to adapt to the two Vincetoxicum species as host plants over the long-term is discussed

Chapter Electromagnetic Sensing Techniques for Non-Destructive Diagnosis of Civil Engineering Structures

Environmental policy & protocol