Black Medic (Medicago lupulina) Emergence and Emergence Predictors within Florida Strawberry Fields

Weed Science ◽  
2018 ◽  
Vol 67 (2) ◽  
pp. 253-260 ◽  
Author(s):  
Shaun M. Sharpe ◽  
Nathan S. Boyd
Keyword(s):  
Current Control ◽  
Control Measures ◽  
Model Fit ◽  
Burial Depth ◽  
Factors Affecting ◽  
Control Techniques ◽  
Medicago Lupulina ◽  
Controlled Environments ◽  
Field Emergence ◽  
Hand Weeding

AbstractBlack medic (Medicago lupulinaL.) infestations are a concern for Florida strawberry [Fragaria×ananassa(Weston) Duchense ex Rozier (pro sp.) [chiloensis×virginiana] producers. Current control techniques rely on hand weeding or clopyralid application. Coordinating POST control measures with emergence timing can reduce crop competition duration and increase control. The objective of this study was to evaluateM. lupulinaemergence in response to burial depth and temperature and to modelM. lupulinacumulative field emergence under subtropical Florida conditions using growing degree days (GDDs) as a predictor. Two studies were in controlled environments and looked at factors affecting emergence, burial depth, and temperature. A third experiment was a 2-yr emergence study conducted on four commercial strawberry fields in Hillsborough County, FL. Emergence was modeled as a function of accumulated standard and restricted daily GDD accounting, based onM. lupulinadormancy and germination. In Experiment 1,M. lupulinaonly emerged when seed was deposited on the surface. In Experiment 2, there was three-way interaction among temperature, burial depth, and measurement timing (P<0.0001).Medicago lupulinaemerged from as deep as 2 cm at a temperature range between 15 and 25 C.Medicago lupulinafield emergence was not consistent between years, although emergence was consistent across four sites in year 1, with 0 emergence in year 2. Dormancy and germination restrictions increased calibration and validation model fit and reduced GDD inflation, making models usable between years.Medicago lupulinaprimarily emerged during crop establishment, between mid-November and late-December, which corresponds to an ideal timing for control measures before the harvest period.

scholarly journals Control Recommendations for Black Medic (Medicago lupulina) Based on Growth and Development in Competition with Strawberry

Weed Science ◽  
2017 ◽  
Vol 66 (2) ◽  
pp. 226-233 ◽  
Author(s):  
Shaun M. Sharpe ◽  
Nathan S. Boyd ◽  
Peter J. Dittmar ◽  
Greg E. MacDonald ◽  
Rebecca L. Darnell ◽  
...  
Keyword(s):  
Growth And Development ◽  
Plant Size ◽  
Control Measures ◽  
Stem Length ◽  
Plastic Mulch ◽  
Flower Buds ◽  
Medicago Lupulina ◽  
Hand Weeding ◽  
Spray Timing ◽  
Time Frames

Strawberries are an important horticultural crop in Florida. Black medic is among the most problematic weeds within the production system. To better coordinate control measures, black medic growth and development while in competition with strawberry was studied. Twelve plants were randomly selected at each of four field sites in Hillsborough County, FL, in 2014. Plants were repeatedly measured over the growing season for stem length and number of primary branches, flower buds, flowers, and seed clusters. Growing degree days (GDD) were calculated (Tbase=0 C) starting from the hole-punch application of the plastic mulch (October 8, 2014, to October 10, 2014) from weather station data generated from the Florida Automated Weather Network. Strawberry height and width increased consistently across all sites, but black medic growth and development varied considerably. Strawberry suppressed black medic growth up to 1,805 cumulative GDD at three of four sites where black medic remained beneath the strawberry canopy. After 1,805 GDD, the black medic stems still remained below but experienced exponential growth for total stem length and, in turn, flower buds, inflorescence, and immature seed clusters. Ideal clopyralid spray timing based on susceptible plant size was 890 to 1,152 GDD. Optimal hand-weeding time frames would likely occur as the plant stems expand beyond the strawberry canopy (to improve visibility) and before flower production to prevent seed return to the seedbank. First seed production was observed at 1,200 GDD at the earliest site and between 1,966 to 2,365 GDD across all the other sites. Overall, consistent trends were observed across sites, but between-site variability was observed that could not be accounted for by differences in temperature.

scholarly journals Phylogenetic Complexity of Morphologically Identified Anopheles squamosus in Southern Zambia

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 146
Author(s):  
Jordan Hoffman ◽  
Ilinca Ciubotariu ◽  
Limonty Simubali ◽  
Twig Mudenda ◽  
William Moss ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Catchment Area ◽  
Control Strategies ◽  
Light Trap ◽  
Current Control ◽  
Control Measures ◽  
Morphological Identification ◽  
The Past ◽  
Blood Meal Source ◽  
Residual Malaria Transmission

Despite dramatic reductions in malaria cases in the catchment area of Macha Hospital, Choma District, Southern Province in Zambia, prevalence has remained near 1–2% by RDT for the past several years. To investigate residual malaria transmission in the area, this study focuses on the relative abundance, foraging behavior, and phylogenetic relationships of Anopheles squamosus specimens. In 2011, higher than expected rates of anthropophily were observed among “zoophilic” An. squamosus, a species that had sporadically been found to contain Plasmodium falciparum sporozoites. The importance of An. squamosus in the region was reaffirmed in 2016 when P. falciparum sporozoites were detected in numerous An. squamosus specimens. This study analyzed Centers for Disease Control (CDC) light trap collections of adult mosquitoes from two collection schemes: one performed as part of a reactive-test-and-treat program and the second performed along a geographical transect. Morphological identification, molecular verification of anopheline species, and blood meal source were determined on individual samples. Data from these collections supported earlier studies demonstrating An. squamosus to be primarily exophagic and zoophilic, allowing them to evade current control measures. The phylogenetic relationships generated from the specimens in this study illustrate the existence of well supported clade structure among An. squamosus specimens, which further emphasizes the importance of molecular identification of vectors. The primarily exophagic behavior of An. squamosus in these collections also highlights that indoor vector control strategies will not be sufficient for elimination of malaria in southern Zambia.

scholarly journals Timing and Route of Contamination of Patient Rooms With Healthcare-Associated Pathogens

2020 ◽  
Vol 41 (S1) ◽  
pp. s412-s412
Author(s):  
Sarah Redmond ◽  
Jennifer Cadnum ◽  
Basya Pearlmutter ◽  
Natalia Pinto Herrera ◽  
Curtis Donskey
Keyword(s):  
Acute Care Hospital ◽  
Current Control ◽  
Pathogen Transmission ◽  
Control Measures ◽  
Effective Control ◽  
Portable Devices ◽  
Care Hospital ◽  
Spa Typing ◽  
Persistent Problem ◽  
Healthcare Associated

Background: Transmission of healthcare-associated pathogens such as Clostridioides difficile and methicillin-resistant Staphylococcus aureus (MRSA) is a persistent problem in healthcare facilities despite current control measures. A better understanding of the routes of pathogen transmission is needed to develop effective control measures. Methods: We conducted an observational cohort study in an acute-care hospital to identify the timing and route of transfer of pathogens to rooms of newly admitted patients with negative MRSA nares results and no known carriage of other healthcare-associated pathogens. Rooms were thoroughly cleaned and disinfected prior to patient admission. Interactions of patients with personnel and portable equipment were observed, and serial cultures for pathogens were collected from the skin of patients and from surfaces, including those observed to come in contact with personnel and equipment. For MRSA, spa typing was used to determine relatedness of patient and environmental isolates. Results: For the 17 patients enrolled, 1 or more environmental cultures became positive for MRSA in rooms of 10 patients (59%), for C. difficile in rooms of 2 patients (12%) and for vancomycin-resistant enterococci (VRE) in rooms of 2 patients (12%). The patients interacted with an average of 2.4 personnel and 0.6 portable devices per hour of observation. As shown in Figure 1, MRSA contamination of the floor occurred rapidly as personnel entered the room. In a subset of patients, MRSA was subsequently recovered from patients’ socks and bedding and ultimately from the high-touch surfaces in the room (tray table, call button, bedrail). For several patients, MRSA isolates recovered from the floor had the same spa type as isolates subsequently recovered from other sites (eg, socks, bedding, and/or high touch surfaces). The direct transfer of healthcare-associated pathogens from personnel or equipment to high-touch surfaces was not detected. Conclusions: Healthcare-associated pathogens rapidly accumulate on the floor of patient rooms and can be transferred to the socks and bedding of patients and to high-touch surfaces. Healthcare facility floors may be an underappreciated source of pathogen dissemination not addressed by current infection control measures.Funding: NoneDisclosures: None

The decline of the Desert Locust plague in the 1960s: control operations or natural causes?

1979 ◽  
Vol 287 (1022) ◽  
pp. 315-344 ◽  
Keyword(s):  
Control Measures ◽  
Circumstantial Evidence ◽  
Desert Locust ◽  
Control Techniques ◽  
Probable Impact ◽  
The 1960S ◽  
Striking Contrast

The very limited Desert Locust infestations of most years since 1963 have been in striking contrast with the massive attacks experienced up to that time, which were clearly (and often admittedly) beyond the control of the organizations concerned in one or more countries in, for example, every one of the 23 years from 1940 to 1962. Attempting to assess possible effects of control measures on the development of the overall Desert Locust situation, relative to those of natural causes, poses formidable problems. However, new control techniques were deployed on unprecedented scales in particular series of locust campaigns during the early 1960s. Detailed monitoring and mapping of the overall Desert Locust situation provided circumstantial evidence of the probable impact of these campaigns. Further circumstantial evidence of the effects of these developments in methods and organization was provided by the short-lived locust upsurges of 1964 and 1967-8.

scholarly journals Hydrologic Modelling of Construction Site Sediment Control Pond Using SWMM

2021 ◽  
Author(s):  
Renata Krasnova
Keyword(s):  
Stormwater Management ◽  
Current Control ◽  
Control Measures ◽  
Background Information ◽  
Construction Site ◽  
Stormwater Treatment ◽  
Hydrologic Modelling ◽  
Sediment Control ◽  
Sources Of Pollution ◽  
Receiving Waters

Construction activities have been identified as one of the major sources of pollution to receiving waters. Although Erosion and Sediment Control (ESC) measures reduce the amount of sediment exported from construction sites, there are still significant concerns regarding the sufficiency of current control measures to protect receiving waters. This study documents the work completed to monitor and model the performance of a typical stormwater management facility used for erosion and sediment control in suburban construction site. The main objective of this study is to provide background information regarding the performance of stormwater management facilities for treating urban construction runoff prior to discharging to receiving water bodies. The RUNOFF and STORAGE TREATMENT blocks of EPA's stormwater management model (PCSWMM4.4) were used to simulate the quantity and quality of stormwater run-off from the area under construction and assess the performance of stormwater treatment facility (Ballymore Pond) located in Richmond Hill, Ontario. The performance of the construction site sediment control pond was found to be unsatisfactory due to the high outflow concentration of suspended solids. Some specific recommendations to improve its effectiveness have been made.

scholarly journals Hydrologic Modelling of Construction Site Sediment Control Pond Using SWMM

2021 ◽  
Author(s):  
Renata Krasnova
Keyword(s):  
Stormwater Management ◽  
Current Control ◽  
Control Measures ◽  
Background Information ◽  
Construction Site ◽  
Stormwater Treatment ◽  
Hydrologic Modelling ◽  
Sediment Control ◽  
Sources Of Pollution ◽  
Receiving Waters

Construction activities have been identified as one of the major sources of pollution to receiving waters. Although Erosion and Sediment Control (ESC) measures reduce the amount of sediment exported from construction sites, there are still significant concerns regarding the sufficiency of current control measures to protect receiving waters. This study documents the work completed to monitor and model the performance of a typical stormwater management facility used for erosion and sediment control in suburban construction site. The main objective of this study is to provide background information regarding the performance of stormwater management facilities for treating urban construction runoff prior to discharging to receiving water bodies. The RUNOFF and STORAGE TREATMENT blocks of EPA's stormwater management model (PCSWMM4.4) were used to simulate the quantity and quality of stormwater run-off from the area under construction and assess the performance of stormwater treatment facility (Ballymore Pond) located in Richmond Hill, Ontario. The performance of the construction site sediment control pond was found to be unsatisfactory due to the high outflow concentration of suspended solids. Some specific recommendations to improve its effectiveness have been made.

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