Simulated Herbicide Spray Retention on Floating Aquatic Plants as Affected by Carrier Volume and Adjuvant Type

2021 ◽  
pp. 1-23
Author(s):  
Benjamin P. Sperry ◽  
Christopher R. Mudge ◽  
Kurt D. Getsinger

Foliar delivery of herbicides is a common means for plant management in aquatic environments. Though this technique is decades old, little is known about vegetative spray retention relative to this application method. A more complete understanding of maximizing herbicide retention could lead to improved plant management while simultaneously decreasing pesticide load in aquatic environments. Therefore, outdoor mesocosm experiments were conducted in 2020 to evaluate the effect of adjuvant type on foliar spray retention in waterhyacinth. Additionally, the effect of carrier volume on spray retention in waterhyacinth, waterlettuce, and giant salvinia was documented. Spray deposition did not differ among the nine adjuvants tested; however, spray retention was reduced 6 to 11% when an adjuvant was excluded from the spray solution. The effect of carrier volume on spray retention in waterhyacinth, waterlettuce, and giant salvinia was also investigated. Decreases in spray retention was most sensitive to increased carrier volume in waterhyacinth, followed by giant salvinia and waterlettuce. Among species, spray retention potential, as determined by intercept estimates, was greatest in waterlettuce and giant salvinia regardless of carrier volume. Asymptotes estimates for waterhyacinth, waterlettuce, and giant salvinia were 33, 46, and 79% spray retention, respectively. In other words, spray retention was the lowest and remained relatively constant at these values for the high carrier volumes tested (935 and 1870 L ha−1), which were likely due to the presence of pubescence on leaves and flatter leaf architecture represented by waterlettuce and giant salvinia compared to the glabrous vertical leaves of waterhyacinth. Future research will evaluate these concepts under field conditions.

2021 ◽  
Author(s):  
Simerjeet Virk ◽  
Eric Prostko ◽  
Robert Kemerait ◽  
Mark Abney ◽  
Glen Rains ◽  
...  

Growers have rapidly adopted auxin-resistant cotton and soybean technologies. In Georgia, growers who plant auxin-resistant cotton/soybean are required to utilize nozzles that produce larger (coarser) droplets when spraying auxin herbicides to minimize potential off-target movement of pesticides. Consequently, these nozzles are also used in peanut (an important rotational crop with cotton) since changing nozzles between crops is uncommon for growers. However, larger droplets can result in reduced spray coverage which may lead to less effective pest control. Therefore, seven on-farm trials were conducted in commercial peanut fields using commercial sprayers from 2018 to 2020 across four different locations in Georgia to compare the spray performance of air-induction (AI) nozzles that produce very coarse to ultra coarse droplets (VMD50 ≥ 404 microns) with non-AI (conventional flat fan) nozzles that produce medium to coarse droplets (403≥VMD50≥236 microns) for pest management in peanuts. For each trial, test treatments were implemented in large replicated strips where each strip represented a nozzle type. For nozzle comparison, XR and XRC represented non-AI nozzles while TADF, TDXL, TTI, and TTI60 represented the commonly used AI nozzles in these trials. Spray deposition data for each nozzle along with disease ratings, weed and insect control ratings were collected in all on-farm trials. Peanut yield was collected at harvest. Results indicated that the AI nozzles produced larger droplets than the non-AI nozzles in all nozzle tests; however, the spray coverage varied among the nozzle types. Nozzle type did not influence pest (weed, disease and insect) control, or peanut yield (p≤0.10) in any of the on-farm trials. These results suggested that peanut growers can utilize these coarser droplet nozzles for pest management in fields with low to average pest pressure during the season. Future research on nozzle evaluation needs to investigate the influence of droplet size, carrier volume, and pressure on coverage and canopy penetration.


1991 ◽  
Vol 33 (3) ◽  
pp. 281-304 ◽  
Author(s):  
B. Terence Grayson ◽  
James D. Webb ◽  
Simon E. Pack ◽  
Dean Edwards

1987 ◽  
Vol 119 (S140) ◽  
pp. 15-30 ◽  
Author(s):  
Henry R. Murkin ◽  
Bruce D.J. Batt

AbstractThis paper reviews the interactions of vertebrates and invertebrates in peatlands and marshes to assess current knowledge and future research needs. Living organisms may interact through a number of direct trophic and nutrient pathways and a variety of non-trophic, habitat-dependent relationships. Freshwater marshes and peatlands are dynamic aquatic environments and organisms that occupy these areas must be adapted to a wide range of environmental conditions. The avian community illustrates the main interactions of invertebrates and vertebrates in peatlands and marshes. Waterfowl, along with fish and furbearers, are the most economically important vertebrates using these habitats. Each of these groups has important trophic and habitat links to the invertebrates within wetlands.The most common interaction between vertebrates and invertebrates is the use of invertebrates as food by vertebrates. Few studies, however, have dealt with trophic dynamics or secondary production within wetlands. Waterfowl, fish, and many other wetland vertebrates, during all or part of their life cycles, regularly feed on invertebrates. Some invertebrates are vectors of disease and parasites to vertebrates. Vertebrates can directly affect the structural substrate that invertebrates depend on as habitat through consumption of macrophytes or through the use of living and dead plant material in the construction of houses and nests. Conversely, herbivorous invertebrates may directly affect the survival and distribution of macrophytes in wetlands. Macrophyte distribution, in turn, is an important factor in determining vertebrate use of wetlands. The general lack of both taxonomic and ecological information on invertebrates in wetlands is the main hindrance to future elucidation of vertebrate–invertebrate interactions in these environments. Development of invertebrate sampling techniques suitable for wetland habitats also is necessary. More specific research needs must be met to develop a better understanding of the structure and function of these dynamic systems.


Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1833 ◽  
Author(s):  
Xiaojie Shi ◽  
Xingshuang An ◽  
Qingxue Zhao ◽  
Huimin Liu ◽  
Lianming Xia ◽  
...  

The Internet of Things (IoT) has tremendous success in health care, smart city, industrial production and so on. Protected agriculture is one of the fields which has broad application prospects of IoT. Protected agriculture is a mode of highly efficient development of modern agriculture that uses artificial techniques to change climatic factors such as temperature, to create environmental conditions suitable for the growth of animals and plants. This review aims to gain insight into the state-of-the-art of IoT applications in protected agriculture and to identify the system structure and key technologies. Therefore, we completed a systematic literature review of IoT research and deployments in protected agriculture over the past 10 years and evaluated the contributions made by different academicians and organizations. Selected references were clustered into three application domains corresponding to plant management, animal farming and food/agricultural product supply traceability. Furthermore, we discussed the challenges along with future research prospects, to help new researchers of this domain understand the current research progress of IoT in protected agriculture and to propose more novel and innovative ideas in the future.


HortScience ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 667-675
Author(s):  
Ockert P.J. Stander ◽  
Jade North ◽  
Jan M. Van Niekerk ◽  
Tertia Van Wyk ◽  
Claire Love ◽  
...  

This study aimed to determine the effects of different types of nonpermanent netting (NPN) on foliar spray deposition, insect pest prevalence, and production and fruit quality of ‘Nadorcott’ mandarin (Citrus reticulata) trees in a commercial orchard at Citrusdal (lat. 32 32′31″S, long. 19 0′42″E), Western Cape, South Africa. The deposition quantity (FPC%) of foliar spray volumes of 3500, 7000, or 15,000 L·ha−1 was greater for leaves of control trees compared with leaves treated with NPN during summer (January) (8.8 vs. 6.1; P = 0.0055) and winter (June) (4.8 vs. 3.1; P = 0.0035). Deposition uniformity (CV%) was better for control leaves during summer (64.9 vs. 75.2; P = 0.0062) and winter (59.6 vs. 80.5; P = 0.0014), and deposition quality (ICD%) was better during winter (79.4 vs. 84.2; P = 0.0393). There were no differences in FPC%, CV%, and ICD% for fruit when foliar spray volumes of 3500 and 15,000 L·ha−1 were used for the control and NPN treatment groups during winter. However, with a foliar spray volume of 7500 L·ha−1, fruit from the control treatment group had greater FPC% (19.3 vs. 6.1; P = 0.0262), CV% (70.3 vs. 50.9; P = 0.0484), and ICD% (57.1 vs. 79.9; P = 0.0157). There were no differences in macronutrient concentrations between the leaves of trees subjected to control and NPN treatments, but leaf zinc (<81%; P = 0.0317) and iron (<78%; P = 0.0041) concentrations were lower with the NPN treatment. During short NPN treatments, fruit yield was reduced by ≈37% compared with that after control treatment, and longer NPN treatments had no effect on fruit yield. The reduction in fruit yield with NPN was not related to the effects of NPN on foliar spray deposition or to lower leaf micronutrient concentrations. The lower fruit yield during short NPN treatments was most likely caused by fruit drop that was exacerbated by the removal of the NPN. In the long NPN treatment group, fruit damage caused by sunburn was reduced by 17%, but the outer canopy fruit experienced increased wind damage or scarring. Except for the lower titratable acidity content with the shortest NPN treatment and the higher Brix°:TA ratio with two NPN treatments, NPN did not impact other fruit quality attributes. The use of NPN excluded male wild false codling moths (Thaumatotibia leucotreta) (FCM) males; however, it was still possible to capture a very small amount of mass-released sterile FCM and wild fruit flies under the NPN.


2021 ◽  
Author(s):  
Karthikeyan Perumal ◽  
Subagunasekar Muthuramalingam

Abstract Purpose: Microplastics (MPs) are ubiquitous, persistent pollutants that are reported in abundance in all environments and biota. This review highlights the identification, distribution and concentration of microplastics in all aquatic environments and biota in the India region which is one of the least studied with only forty-four papers published on microplastics during 2013-2020 in the web of science. Results: The present review focuses on the concentration of microplastics in different aquatic environments such as 3096 items/kg in marine sediments, 106 items/kg in biota, 59 items/L in seawater, 175 items/kg in sea salt, 33.9 items/L in lake water, 336 items/kg in lake sediments, 288 pieces/m3 in river water, and 328 items/kg in river sediments. Conclusion: Consequently, we studied the distribution and occurrence of pollution from MPs in coastal and freshwater environments such as rivers, lakes and biota. Therefore, we propose extending studies in all the above areas of microplastics knowing that there are many unique aquatic habitats and species that are yet unexplored. For future research, we suggest new methods for sampling MPs in all marine ecosystems and biota. Assessing research in each of these ways will allow suggesting a microplastic threshold level and devising control initiatives to minimize plastic consumption and its eventual hazard to the aquatic ecosystem. Moreover enforcing strict laws, enhancing legal initiatives, well-planned comprehensive waste management policies and spontaneous public engagement are essential to create awareness of marine plastic pollution and reduce the adverse effects of land-based plastics.


Author(s):  
Chaoshu Zeng ◽  
Guiomar Rotllant ◽  
Luis Giménez ◽  
Nicholas Romano

The vast majority of crustaceans are aquatic, living in either marine or freshwater environments. Marine crustaceans—such as copepods, in particular—are ubiquitous in the oceans and perhaps the most numerous metazoans on Earth. Because crustaceans occur in all marine habitats, their larvae are exposed to highly diverse and sometimes variable environmental conditions, including extreme situations in which various environmental factors exert significant effects on larval growth and development. This chapter first describes the effects of food availability on crustacean larvae. Food paucity is a commonly occurring scenario in the wild, which can directly affect larval growth and development and, in severe cases, results in mortality. In the subsequent sections, we cover the effects of temperature and salinity—the two most prominent physical parameters in the aquatic environments—on growth and development of crustacean larvae. We then discuss the influence of other important physicochemical factors in aquatic environments on larval growth and development, including dissolved oxygen, light, ocean acidification, and pollutants. Finally, the last two sections of this chapter discuss synergistic effects of different environmental factors and suggest future research directions in this field.


2020 ◽  
Author(s):  
Tim van Emmerik ◽  
Anna Schwarz

&lt;p&gt;Macroplastic (&gt;0.5 cm) pollution in aquatic environments is an emerging environmental risk, as it negatively impacts ecosystems, endangers aquatic species, and causes economic damage. Rivers are known to play a crucial role in transporting land-based plastic waste into the world&amp;#8217;s oceans. However, rivers and their ecosystems are also directly affected by plastic pollution. To better quantify global plastic pollution pathways and to effectively reduce sources and risks, a thorough understanding of riverine macroplastic sources, transport, fate and effects is crucial. In our presentation, we discuss the current scientific state on macroplastic in rivers and evaluate existing knowledge gaps. We discuss the origin and fate of riverine plastics, including processes and factors influencing macroplastic transport and its spatiotemporal variation. Moreover, we present an overview of monitoring and modeling efforts to characterize riverine plastic transport and give examples of typical values from around the world (van Emmerik &amp; Schwarz, 2020). With our presentation, we aim to present a comprehensive overview of riverine macroplastic research to date and suggest multiple ways forward for future research.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;van Emmerik, T, Schwarz, A. Plastic debris in rivers. WIREs Water. 2020; 7:e1398. https://doi.org/10.1002/wat2.1398&lt;/p&gt;


2017 ◽  
Vol 107 (0) ◽  
Author(s):  
Florencia Zilli ◽  
Julia del Barco ◽  
Agustín Vanzetti

ABSTRACT Currently, it is widely recognized that invertebrates play key roles in neotropical floodplains and in many other environments worldwide. However, little information has been published concerning their biometry, in spite that it represents an essential tool for many different studies. Here, we provided length-mass and length-length relationships by fitting the linearized model (log10 Y = log10a + b log10 X) and several mean biomass ratios ± SE for bivalves, gastropods, quironomids, ephemeropterans, oligochaetes and hirudineans. We measured, weighed, oven dried and incinerated to ashes specimens collected from 2005 to 2014 in the Paraná River, Argentina. The lineal equations had fit levels higher than 75% in most of the significant regressions. Hence, when slopes were compared, differences raised from ontogeny and phylogeny of taxa. Additionally, slopes resulted different from constants of other regions, types of environments and climates. In addition, organic matter ratios resulted significantly different among invertebrates according to their feeding types. The equations and ratios that we provided will facilitate future research on life history, productivity and energy transference in the food webs of invertebrates inhabiting floodplain wetlands and can be used as tools for planning management strategies and in restoration projects of aquatic environments.


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