scholarly journals Field Distance Effects of Fipronil and Chlorfenapyr as Soil Termiticides Against the Desert Subterranean Termite, Heterotermes aureus (Blattodea: Rhinotermitidae)

Sociobiology ◽  
2020 ◽  
Vol 67 (1) ◽  
pp. 94
Author(s):  
Paul B Baker ◽  
Javier G Miguelena
Keyword(s):  
Spatial Pattern ◽  
Soil Treatment ◽  
Field Conditions ◽  
Subterranean Termite ◽  
Treated Soil ◽  
Full Control ◽  
Distance Effects ◽  
Delayed Toxicity ◽  
The Impact ◽  
Desirable Trait

A desirable trait of termiticides is that they suppress termite activity at a distance from the site of application. Fipronil and chlorfenapyr are two non-repellent termiticides that display delayed toxicity and are therefore good candidates for yielding distance effects. We assessed their effects as soil-applied termiticides for the management of the desert subterranean termite, Heterotermes aureus (Snyder), under field conditions in southern Arizona. Our approach involved recording termite activity within field experimental grids consisting of termite monitoring stations at selected distances from a termiticide application perimeter. Fipronil-treated plots experienced large and significant reductions in termite presence and abundance relative to controls in stations immediately adjacent to treated soil. However, there was no evidence of reductions in termite activity in stations further away from the soil treatment. In contrast, termite abundance and presence in stations decreased relatively to controls after chlorfenapyr application in whole experimental grids and in several grid sections spatially separated from treated soil. These reductions were especially evident in the five central stations surrounded by the treatment perimeter and in the furthest set of stations. The spatial pattern of changes in chlorfenapyr plots was consistent with termiticide transfer as a mechanism behind distance effects. The impact of fipronil and chlorfenapyr on termite populations in our study suggests that they can both be useful for the management of H. aureus, although each might be suited for differentmanagement goals. Our results also suggest that perimeter treatments alone are not sufficient to accomplish full control of large H. aureus infestations.

scholarly journals Impact of Microwave Soil Heating on the Yield and Nutritive Value of Rice Crop

Agriculture ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 134
Author(s):  
Muhammad Jamal Khan ◽  
Graham Brodie ◽  
Long Cheng ◽  
Wenwen Liu ◽  
Ravneet Jhajj
Keyword(s):  
Nutritive Value ◽  
Biomass Yield ◽  
Crop Productivity ◽  
Soil Treatment ◽  
Field Conditions ◽  
N Accumulation ◽  
Soil Heating ◽  
Accumulation Pattern ◽  
Dry Biomass ◽  
The Impact

Microwave (MW) soil heating has been shown to deplete the soil weed seedbank and increase crop productivity. However, the impact of MW soil heating on the nutritive value of crops is unknown. In this study, two field trials were conducted to evaluate the effect of pre-sowing MW soil treatment with a duration of 60 s and an untreated control, which were assigned in a randomized complete block design with five replicates at two locations, on the yield and nitrogen (N) accumulation pattern of rice crops. At Jerilderie site, soil heating at up to 70–75 °C significantly (p ˂ 0.09) increased the rice biomass yield by 43.03% compared with rice biomass yield in untreated soils, while at Dookie site no significant increase in biomass yield was detected. Dry matter digestibility (DMD), ash, and N% did not change, whereas the N accumulation in dry biomass was significantly (p ˂ 0.09) higher at both sites (8.2% at Dookie and 43.4% at Jerilderie) and N use efficiency (10–40%) increased in response to MW soil treatment. The current study suggests that MW soil treatment can potentially enhance the crop productivity and N accumulation in dry biomass under field conditions. Future research is needed to understand the impact of MW soil heating on the productivity and nutritive value of different fodder crops under field conditions.

scholarly journals Application of Bacillus pumilus isolates for management of black rot disease in strawberry

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Farid Abd-El-Kareem ◽  
Ibrahim E. Elshahawy ◽  
Mahfouz M. M. Abd-Elgawad
Keyword(s):  
Root Rot ◽  
Bacillus Pumilus ◽  
Field Conditions ◽  
Black Rot ◽  
Bacterial Isolates ◽  
Black Root Rot ◽  
Root Rot Disease ◽  
Growth Area ◽  
Rot Disease ◽  
The Impact

Abstract Background Black root rot of strawberry plants caused by Rhizoctonia solani, Fusarium solani, and Pythium sp. is a serious disease in Egypt. Biocontrol agents have frequently proved to possess paramount and safe tools against many diseases. The impact of soil treatments with 3 Bacillus pumilus isolates on black root rot disease of strawberry plants caused by R. solani, F., and Pythium sp. under laboratory and field conditions was examined herein on the commonly used ‘Festival’ strawberry cultivar. To increase the bacterial adhesion and distribution on the roots, each seedling was dipped in bacterial cell suspension at 1 × 108 colony-forming units/ml of each separate bacterial isolate for 30 min then mixed with 5% Arabic gum. Results The tested B. pumilus isolates significantly reduced the growth area of these 3 fungi. The two bacterial isolates Nos. 2 and 3 reduced the growth area by more than 85.2, 83.6, and 89.0% for R. solani, F. solani, and Pythium sp., respectively. Likewise, the 3 bacterial isolates significantly (P ≤ 0.05) inhibited the disease under field conditions. Isolates Nos. 2 and 3 suppressed the disease incidence by 64.4 and 68.9% and disease severity by 65.3 and 67.3%, respectively. The fungicide Actamyl had effect similar to that of the 2 isolates. B. pumilus isolates significantly enhanced growth parameters and yields of strawberry plants; isolates Nos. 2 and 3 raised the yield by 66.7 and 73.3%, respectively. Conclusions Bacillus pumilus isolates could effectively manage the black rot disease in strawberry herein. Due to the significant impact of the root rot disease on strawberry yield, B. pumilus should be further tested to manage the disease on strawberry on large scale in Egypt.

scholarly journals Influence of Flower Thrips on Fusarium Hardlock Severity

Plant Disease ◽  
2007 ◽  
Vol 91 (11) ◽  
pp. 1423-1429 ◽  
Author(s):  
D. J. Mailhot ◽  
J. J. Marois ◽  
D. L. Wright
Keyword(s):  
Gossypium Hirsutum ◽  
Untreated Control ◽  
Yield Loss ◽  
Fusarium Verticillioides ◽  
Field Conditions ◽  
Control Group ◽  
Flower Thrips ◽  
The Impact ◽  
Field Plots

Cotton (Gossypium hirsutum) fiber is sometimes affected by hardlock, which is characterized by a failure of the fiber to expand outward from the boll at maturity. Because affected fiber is inaccessible to mechanical harvesters, yield loss can be considerable. Hardlock has been linked to infection by Fusarium verticillioides. The involvement of flower thrips (Frankliniella spp.), which are commonly found in cotton flowers, was explored. At 1100 h, approximately 10% of cotton flowers contained thrips that were carrying F. verticillioides. The effect of thrips and/or Fusarium in flowers and bolls was explored under greenhouse conditions. Exposing flowers to Fusarium and thrips resulted in bolls with the most severe symptoms. Exposure to either Fusarium or thrips alone resulted in more hardlock than was noted in the control group. The impact of thrips was also evaluated under field conditions. Field plots were treated with insecticides, a fungicide, both, or left untreated. Insecticides reduced thrips numbers and reduced hardlock severity. The fungicide had no impact on thrips numbers and was less effective at reducing hardlock. Combining insecticide and fungicide applications was no more effective than using insecticides alone, although it more frequently increased yield. The untreated control plots generally had the most severe hardlock and lowest yields. Reducing hardlock severity resulted in higher yields, although not consistently. These studies suggest that thrips increase the severity of hardlock, and reducing their numbers may diminish hardlock severity.

scholarly journals Spatiotemporal Variance Assessment of Urban Rainstorm Waterlogging Affected by Impervious Surface Expansion: A Case Study of Guangzhou, China

2018 ◽  
Vol 10 (10) ◽  
pp. 3761 ◽  
Author(s):  
Huafei Yu ◽  
Yaolong Zhao ◽  
Yingchun Fu ◽  
Le Li
Keyword(s):  
Spatial Pattern ◽  
Urban Renewal ◽  
Impervious Surface ◽  
City Centre ◽  
Impervious Surfaces ◽  
Surface Expansion ◽  
The Impact ◽  
Gwr Model ◽  
Runoff Plots

Urban rainstorm waterlogging has become a typical “city disease” in China. It can result in a huge loss of social economy and personal property, accordingly hindering the sustainable development of a city. Impervious surface expansion, especially the irregular spatial pattern of impervious surfaces, derived from rapid urbanization processes has been proven to be one of the main influential factors behind urban waterlogging. Therefore, optimizing the spatial pattern of impervious surfaces through urban renewal is an effective channel through which to attenuate urban waterlogging risk for developed urban areas. However, the most important step for the optimization of the spatial pattern of impervious surfaces is to understand the mechanism of the impact of urbanization processes, especially the spatiotemporal pattern of impervious surfaces, on urban waterlogging. This research aims to elucidate the mechanism of urbanization’s impact on waterlogging by analysing the spatiotemporal characteristics and variance of urban waterlogging affected by urban impervious surfaces in a case study of Guangzhou in China. First, the study area was divided into runoff plots by means of the hydrologic analysis method, based on which the analysis of spatiotemporal variance was carried out. Then, due to the heterogeneity of urban impervious surface effects on waterlogging, a geographically weighted regression (GWR) model was utilized to assess the spatiotemporal variance of the impact of impervious surface expansion on urban rainstorm waterlogging during the period from the 1990s to the 2010s. The results reveal that urban rainstorm waterlogging significantly expanded in a dense and circular layer surrounding the city centre, similar to the impervious surface expansion affected by urbanization policies. Taking the urban runoff plot as the research unit, GWR has achieved a good modelling effect for urban storm waterlogging. The results show that the impervious surfaces in the runoff plots of the southeastern part of Yuexiu, the southern part of Tianhe and the western part of Haizhu, which have experienced major urban engineering construction, have the strongest correlation with urban rainstorm waterlogging. However, for different runoff plots, the impact of impervious surfaces on urban waterlogging is quite different, as there exist other influence factors in the various runoff plots, although the impervious surface is one of the main factors. This result means that urban renewal strategy to optimize the spatial pattern of impervious surfaces for urban rainstorm waterlogging prevention and control should be different for different runoff plots. The results of the GWR model analysis can provide useful information for urban renewal strategy-making.

scholarly journals Sustainable Mountain Village Construction Adapted to Livelihood, Topography, and Hydrology: A Case of Dong Villages in Southeast Guizhou, China

2018 ◽  
Vol 10 (12) ◽  
pp. 4619
Author(s):  
Zhengxu Zhou ◽  
Ziyu Jia ◽  
Nian Wang ◽  
Ming Fang
Keyword(s):  
Spatial Pattern ◽  
Rural Areas ◽  
Paddy Field ◽  
Sustainable Construction ◽  
Ecological Stability ◽  
Mountain Valley ◽  
Sustainable Environment ◽  
Water Pond ◽  
Urban And Rural Areas ◽  
The Impact

A sustainable environment needs the effort and experience from both urban and rural areas. Some villages have achieved sustainability utilizing the concept of ecological stability. This paper takes the Dong villages in the Duliujiang River Basin in the Southeastern Guizhou as an example. Based on the anthropological “ethnographic text” and the morphological “village space information”, this paper analyzes the impact of the mountain rice livelihood model and different hydrological–topographic conditions on the spatial pattern of settlements, focusing on the sustainable construction wisdom. The findings are as follows: (1) Dong people’s migration follows the “River Valley–Mountain Valley–Mountain Slope” path, with maintenance of the rice livelihood model and, finally, derived from the “Mountain–Water–Forest–Paddy Field–Village” spatial pattern, the “Mountain–Water–(Pond)–Field–Forest–Village”, “Mountain–Water–Terrace–Forest–Village” settlement space patterns are formed. (2) The Dong’s settlements form a sustainable overall space. “Mountain–Water–Forest–Paddy Field” each play an ecological role and form an organic whole. Their management mechanism of utilizing limited natural resources has played an important management and supervision role. (3) The natural base of “Mountain–Water–Forest–Paddy Field–Village” is in accordance with their livelihood model and social culture, forming a unique ecosystem. It has become the basic environment for them to obtain survival sustenance, which still has prominent values today.

Effect of cold temperature on the rate of natural attenuation of benzene, toluene, ethylbenzene, and the three isomers of xylene (BTEX)

2010 ◽  
Vol 47 (5) ◽  
pp. 516-527 ◽  
Author(s):  
Ania C. Ulrich ◽  
Kristen Tappenden ◽  
James Armstrong ◽  
Kevin W. Biggar
Keyword(s):  
Natural Attenuation ◽  
Field Conditions ◽  
Published Data ◽  
Anaerobic Conditions ◽  
Data Set ◽  
Cold Temperatures ◽  
Site Analysis ◽  
Benzene Toluene ◽  
The Impact ◽  
Hydrogeological Information

The impact of cold temperatures on natural attenuation rates is poorly understood and compounded by the lack of published data, particularly under field conditions. This paper presents a collection of data from monitoring and remediation projects completed at cold temperatures. The data set was compiled from 55 studies under anaerobic conditions (46 field and nine laboratory) from sites where groundwater temperatures are typically less than 15 °C. By normalizing the data to +5 and +10 °C, the scatter in rates for BTEX degradation in groundwater was reduced by 33% to 66%. In an attempt to address the paucity of data on natural attenuation rates under cold temperatures, this study has compiled and normalized 101 anaerobic BTEX natural attenuation rates. Eleven of the 55 studies and 43 of the 101 rates presented in this study have not been previously published. Additionally, this study has compiled, for each site, relevant contaminant and hydrogeological information that can be reviewed to choose appropriate rates for preliminary site analysis.

scholarly journals Temporal variability of carbon recycling in coastal sediments influenced by rivers: assessing the impact of flood inputs in the Rhône River prodelta

2010 ◽  
Vol 7 (3) ◽  
pp. 1187-1205 ◽  
Author(s):  
C. Cathalot ◽  
C. Rabouille ◽  
L. Pastor ◽  
B. Deflandre ◽  
E. Viollier ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Continental Shelf ◽  
Spatial Pattern ◽  
River Mouth ◽  
Ex Situ ◽  
Rhône River ◽  
Reactive Material ◽  
Degradation Rates ◽  
Rhone River ◽  
The Impact

Abstract. River deltas are particularly important in the marine carbon cycle as they represent the transition between terrestrial and marine carbon: linked to major burial zones, they are reprocessing zones where large carbon fluxes can be mineralized. In order to estimate this mineralization, sediment oxygen uptake rates were measured in continental shelf sediments and river prodelta over different seasons near the outlet of the Rhône River in the Mediterranean Sea. On a selected set of 10 stations in the river prodelta and nearby continental shelf, in situ diffusive oxygen uptake (DOU) and laboratory total oxygen uptake (TOU) measurements were performed in early spring and summer 2007 and late spring and winter 2008. In and ex situ DOU did not show any significant differences except for shallowest organic rich stations. Sediment DOU rates show highest values concentrated close to the river mouth (approx. 20 mmol O2 m−2 d−1) and decrease offshore to values around 4.5 mmol O2 m−2 d−1 with lowest gradients in a south west direction linked to the preferential transport of the finest riverine material. Core incubation TOU showed the same spatial pattern with an averaged TOU/DOU ratio of 1.2±0.4. Temporal variations of sediment DOU over different sampling periods, spring summer and late fall, were limited and benthic mineralization rates presented a stable spatial pattern. A flood of the Rhône River occurred in June 2008 and delivered up to 30 cm of new soft muddy deposit. Immediately after this flood, sediment DOU rates close to the river mouth dropped from around 15–20 mmol O2 m−2 d−1 to values close to 10 mmol O2 m−2 d−1, in response to the deposition near the river outlet of low reactivity organic matter associated to fine material. Six months later, the oxygen distribution had relaxed back to its initial stage: the initial spatial distribution was found again underlining the active microbial degradation rates involved and the role of further deposits. These results highlight the immediate response of the sediment oxygen system to flood deposit and the rapid relaxation of this system towards its initial state (6 months or less) potentially linked to further deposits of reactive material.

Development of Active and Passive Fatigue Manipulations Using a Driving Simulator

2007 ◽  
Vol 51 (18) ◽  
pp. 1237-1241 ◽  
Author(s):  
Dyani J. Saxby ◽  
Gerald Matthews ◽  
Edward M. Hitchcock ◽  
Joel S. Warm
Keyword(s):  
Time Course ◽  
Passive Control ◽  
Driving Simulator ◽  
Negative Mood ◽  
Subjective Response ◽  
Passive Condition ◽  
Full Control ◽  
Active Condition ◽  
The Impact ◽  
Simulated Wind

The present study investigates driving simulator methodologies for inducing qualitatively different patterns of subjective response. The study tested Desmond and Hancock's (2001) theory that there may be two types of fatigue: active and passive. 108 undergraduates participated. There were 3 conditions (active, passive, control) and 3 durations (10, 30, 50 minutes). The active condition used simulated wind gusts to increase the required number of steering and acceleration changes. The passive condition was fully automated. In the control condition, drivers were in full control of steering and acceleration. Task engagement (e.g., energy) was lowest in the passive fatigue condition, followed by the control and active conditions. Distress (e.g., negative mood) was found to be highest in the active fatigue condition. The time course of fatigue responses was also determined. The results suggest methods for developing manipulations to determine the impact of fatigue on performance.

Leaching of Seven s-Triazines

Weed Science ◽  
1968 ◽  
Vol 16 (2) ◽  
pp. 117-120 ◽  
Author(s):  
E. G. Rodgers
Keyword(s):  
Sandy Soil ◽  
Avena Sativa ◽  
Soil Samples ◽  
Field Conditions ◽  
Soil Concentration ◽  
Treated Soil ◽  
Growing Period ◽  
Leaf Chlorosis

Leaching of seven s-triazines in Lakeland fine sandy soil under greenhouse and field conditions was demonstrated by use of oats (Avena sativa L., var Seminole) and cucumber (Cucumis sativis L., var. Palomar) for bioassay. Depth of leaching was determined by abnormalities of these species grown in soil samples from the surface of treated soil to a depth of 22 in in the field and to 36 in in columns. Symptoms of injury by the different materials were similar and included primarily leaf chlorosis of both species and bending and breaking of cucumber stems within 7 to 10 days after planting; plants that failed to survive usually died 12 to 14 days after planting. Leaching of 2-methoxy-4-ethylamino-6-isopropylamino-s-triazine (atratone) was greatest, followed in decreasing order by 2-chloro-4,6-bis(isopropylamino)-s-triazine (propazine), 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine), 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine), 2-chloro-4-diethylamino-6-isopropylamino-s-triazine (ipazine), 2-ethylamino-4-isopropylamino-6-methylmercapto-s-triazine (ametryne), and 2,4-bis(isopropylamino)-6-methylmercapto-s-triazine (prometryne). Oats did not significantly reduce the soil concentration of ametryne and prometryne during a growing period of 56 days.

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