Studies on the Chemical Control of Cacao Mirids, Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl

1959 ◽  
Vol 50 (1) ◽  
pp. 13-23 ◽  
Author(s):  
F. Raw
Keyword(s):  
Prolonged Exposure ◽  
Field Tests ◽  
Field Trials ◽  
Natural Conditions ◽  
Surface Deposit ◽  
Promising Alternative ◽  
Residual Toxicity ◽  
First Instar ◽  
Sahlbergella Singularis ◽  
Incomplete Coverage

Laboratory and field tests were made to investigate the toxicity, mode of action and persistence of technical DDT and γ BHC when applied to cacao in Ghana to control the Mirids, Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl. The insecticides were tested at concentrations previously used in field trials. D. theobroma, S. singularis and Tribolium castaneum (Hbst.) were used as test insects. Preliminary tests with aldrin, chlordane and dieldrin were also made.Cacao pods were sprayed to drip point with the test insecticides and the deposit was allowed to dry. Mirid nymphs were placed on the pods and the rate of knockdown and the mortality after exposure for a test period was recorded. These tests showed that BHC had a higher toxicity and acted much more quickly than DDT. BHC greatly reduced feeding.Fumigant action was tested by spraying cacao leaves to drip point with the test insecticides, allowing the deposit to dry, and then exposing Mirid nymphs and adults over discs cut from the leaves. BHC had a powerful but transient fumigant action; adults, fifth- and second-instar nymphs were killed after, respectively, ½, 4 and 3 hours’ exposure at 28–30°C. over leaves treated with 0·25 per cent, γ BHC. No fumigant effect was observed after prolonged exposure over leaves treated with 2·5 per cent, technical DDT.Persistence was studied by treating cacao leaves and pods growing under natural conditions and then testing the residual deposit at intervals. Tests with T. castaneum showed that when leaves were sprayed to drip point the residual toxicity of 1·25 and 2·5 per cent, technical DDT fell steadily and was negligible after an interval of three and six weeks, respectively; that of 0·25–2 per cent, γ BHC was negligible after 2–3 days. Corresponding tests with Mirids on pods were less consistent but suggested that 2·5 per cent, technical DDT was still effective against first-instar nymphs after three weeks; 0·25 per cent, γ BHC had a residual toxic effect for at least several days and depressed feeding greatly for at least a fortnight. It is suggested that BHC may have a local systemic action which persists after the surface deposit becomes ineffective.Of the other insecticides tested, aldrin had a high toxicity and powerful fumigant action and appeared to be the most promising alternative to BHC.It was concluded that BHC would be more effective than DDT when treating mature cacao because, in addition to its higher toxicity and quicker action, its fumigant action would compensate for incomplete coverage by low-volume spraying.

scholarly journals Modified Humic Substances as Soil Conditioners: Laboratory and Field Trials

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 150
Author(s):  
Natalia A. Kulikova ◽  
Alexander B. Volikov ◽  
Olga I. Filippova ◽  
Vladimir A. Kholodov ◽  
Nadezhda V. Yaroslavtseva ◽  
...  
Keyword(s):  
Humic Substances ◽  
Soil Aggregates ◽  
Field Tests ◽  
Performance Testing ◽  
Field Trials ◽  
Soil Conditioner ◽  
Model Soil ◽  
Substrate Induced Respiration ◽  
And Performance ◽  
Survival Of Seedlings

The paper is devoted to the development and performance testing of a soil conditioner based on leonardite humic substances (LHS) modified with 3-aminopropyltriethoxysilane (APTES). The modified HS were obtained by adding APTES to LHS solution at different mass ratios of LHS and APTES, followed by the investigation of siloxane structures using 31Si NMR spectroscopy. The Urbic Technosol was used as a model soil. The size and amount of water-stable soil aggregates were estimated using wet sieving and laser diffraction, respectively. Toxicity was evaluated by monitoring microbial substrate-induced respiration (SIR) and seedling bioassay. Laboratory column experiments demonstrated an increase in water-stability of the 3–5 mm soil aggregates after LHS-APTES application. Field tests showed an increase in the average weighted diameter of micro aggregates (from 59 to 73 μm) and water-stable macroaggregates (from 1.6 to 2.9 mm) due to the LHS-APTES amendment. A substantial increase in SIR from 5 to 9 mg CO2 (kg h)−1 was detected. Better survival of seedlings was observed. The obtained beneficial results indicate that APTES-modified HS can be successfully used as a soil conditioner. The formation of extended siloxane networks was suggested as the main mechanism of the observed improvement in the structure of the amended soils.

Comparison of Water and Gas Tracers Field Breakthrough

2021 ◽  
Author(s):  
Hsieh Chen ◽  
Sehoon Chang ◽  
Gawain Thomas ◽  
Wei Wang ◽  
Afnan Mashat ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Detection Method ◽  
Tracer Tests ◽  
Field Tests ◽  
Field Trials ◽  
Breakthrough Curves ◽  
Detection Methods ◽  
Reservoir Conditions ◽  
Gas Tracer

Abstract We are developing new classes of barcoded advanced tracers, which, compared to present commercial offerings, can be optically detected in an automated fashion. The eventual goal for the advanced tracers is to deploy cost-effective, ubiquitous, long-term, and full-field tracer tests in supporting large-scale waterflooding optimization for improved oil recovery. In this paper, we compare model predictions to breakthrough data from two field tests of advanced tracers in a pilot during water alternating gas (WAG) cycles, where gas tracer tests have recently been performed as well. Two advanced tracer injections were performed at the test site. For the first injection, only a dipicolinic acid based advanced tracer (DPA) was injected. For the second injection, DPA and a phenanthroline- based advanced tracer, 4,7-bis(sulfonatophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid (BSPPDA), was injected in conjunction with a commercially available fluorobenzoic acid-based tracer (FBA) to benchmark their performance. Produced water samples were collected weekly for tracer analysis. Both newly developed 2D-high performance liquid chromatography/time-resolved fluorescence optical detection method (2D-HPLC/TRF) and liquid chromatography-mass spectrometry (LC-MS) were used to construct the breakthrough curves for the advanced tracers. In parallel, gas chromatography-mass spectrometry (GC-MS) was used to detect FBA tracer. Gas tracer tests have been performed on the same field. Since DPA, BSPPDA and FBA tracers were water tracers as designed, they were expected to appear in between gas tracer breakthroughs, and we observed exactly that for BSPPDA and FBA. Unexpectedly, the DPA predominantly appeared along with gas tracer breakthroughs, suggesting its favorable compatibility with the gas phase. We suspect the presence of some gas components rendered the medium more acidic, which likely protonates DPA molecules, thereby alters its hydrophilicity. A wealth of information could be gathered from the field tests. First, all tracers survived not only the harsh reservoir conditions but also the irregular WAG injections. Their successful detection from the producers suggested robustness of these materials for reservoir applications. Second, the breakthrough curves of the BSPPDA tracers using optical detection method were very similar to those of FBA tracers detected by GC-MS, substantiating the competency of our in-house materials and detection methods to the present commercial offerings. Finally, even though DPA has passed prior lab tests as a good water tracer, its high solubility to gas phase warrants further investigation. This paper summarizes key results from two field trials of the novel barcoded advanced tracers, of which both the tracer materials and detection methods are new to the industry. Importantly, the two co- injected advanced tracers showed opposite correlations to the gas tracers, highlighting the complex physicochemical interactions in reservoir conditions. Nevertheless, the information collected from the field trials is invaluable in enabling further design and utilization of the advanced tracers in fulfilling their wonderful promises.

scholarly journals Managing Bees for Delivering Biological Control Agents and Improved Pollination in Berry and Fruit Cultivation

2015 ◽  
Vol 4 (3) ◽  
pp. 89 ◽  
Author(s):  
Heikki M. T. Hokkanen ◽  
Ingeborg Menzler-Hokkanen ◽  
Marja-Leena Lahdenpera
Keyword(s):  
Crop Protection ◽  
Field Tests ◽  
Weather Conditions ◽  
Field Studies ◽  
Field Trials ◽  
Marketable Yield ◽  
Dissemination Activity ◽  
Grey Mold ◽  
Commercial Farms ◽  
Disease Pressure

<p>Targeted precision biocontrol and improved pollination were studied Europe-wide in the EU ERA-NET CORE ORGANIC 2 project BICOPOLL (Biocontrol and Pollination). A case study was conducted on the management of strawberry grey mold <em>Botrytis cinerea</em>, with the biocontrol fungus, <em>Gliocladium catenulatum</em>, vectored by honey bees or bumble bees. A joint field trial carried out in five countries targeted strawberry cultivations in open field, and included four treatments: untreated control, chemical fungicide, entomovectored biocontrol, and chemical and biocontrol combined. In organic fields, no pesticide treatments were included. The proportion of moldy berries, and/or the marketable yield of healthy berries were recorded from each treatment, along with other parameters of local interest. A pilot study was started in Finland in 2006, and, by 2012, large commercial farms were using entomovectoring. In 2012, field trials were started in Estonia and in Italy, and in 2013-14, these experiments were expanded to Slovenia and Turkey. In total, 26 field tests were conducted using entomovectoring and <em>Gliocladium catenulatum</em> (Prestop<sup>®</sup> Mix) on strawberry, with five additional trials on raspberry. Efficacy results have been excellent throughout the field studies. The results show crop protection equalling or exceeding that provided by a full chemical fungicide program, under all weather conditions, and over a wide geographical range (from Finland to Turkey). Under heavy disease pressure, entomovectoring provided on average a 47% disease reduction, which was the same as multiple fungicide sprays. Under light disease pressure, biocontrol decreased grey mold by an average of 66%, which was greater than fungicide sprays. The concept has proven to be effective on strawberries, raspberries, pears, apples, blueberries, cherries, and grapes. A conservative estimate for Finland is that over 500 ha of strawberry cultivation currently use the technique (≈15% of the strawberry growing area). To make full use of the entomovectoring technique, organic berry and fruit growers are encouraged to (i) keep bees, or to hire the service from local beekeepers for entomovectoring; and (ii) manage vegetation within and around the target crop to support the activity of bees and other pollinators, which can help to disseminate the beneficial microbial populations within the crop. Beekeepers are encouraged to (i) market pollination and biocontrol services to fruit and berry growers, and (ii) ensure that all operations are effective in mananging bees and their microbe dissemination activity. Biocontrol product manufacturers are encouraged to further develop products and their formulations specifically for entomovectoring, because current formulations are suboptimal as they are initially optimized for other uses (e.g., mixing into the soil).</p>

scholarly journals Pengembangan Bahan Ajar Tematik Berbasis Nilai-Nilai Keislaman Kelas VI Madrasah Ibtidaiyah

2021 ◽  
Vol 2 (1) ◽  
pp. 1-24
Author(s):  
Sumining Sumining
Keyword(s):  
Research And Development ◽  
Core Competencies ◽  
Field Tests ◽  
Field Trials ◽  
Teaching Materials ◽  
Initial Field ◽  
Post Test ◽  
Leadership Class ◽  
Thematic Learning ◽  
Islamic Values

Development of thematic teaching materials based on Islamic values, especially those related to the contents of the verses of the Alqur'an and / or hadith as the basis of all science. In the available books, there are no thematic teaching materials that are integrated with the Al-Quran and Hadith, as well as Islamic values ??that are able to implement the core competencies of the 2013 curriculum, namely the competence of spiritual attitudes in thematic learning. The formulation of this research is: (1) producing thematic teaching materials based on Islamic values ??theme 7 (Leadership) class 6 Madrasah Ibtidaiyah Negeri 2 Jember. (2) to determine the effectiveness of thematic teaching materials based on Islamic values ??in learning. This study uses a research and development research type, the Borg and Gall model which is divided into 10 steps, namely: (1) research and data collection (2) planning, (3) product draft development, (4) initial field trials, ( 5) revising the results of trials, (6) field trials, (7) improving products from field tests, (8) conducting field trials, (9) improving product results, and (10) disseminating and implementing. The testing technique was carried out by comparing the pre-test and post-test values. The data was calculated using the t-test and processed using the SPSS application to determine the effectiveness of teaching materials. The results of this study indicate: the validation test produces an average of 88.79% with the criteria that the book is very suitable for use in learning. In terms of attractiveness, this book is very interesting to use for students, this is based on the results of the questionnaire data given to students with an average of 88.24% with very attractive qualifications. Meanwhile, from the results of the pre-test and post-test based on the t count which shows that it is greater than the t table, it means that the book is effective for use in learning. Keywords: Teaching Materials; Thematic Learning; Islamic Value Pengembangan bahan ajar tematik berbasis nilai keislaman, terutama yang terkait dengan isi ayat Alqur'an dan/atau hadits sebagai dasar dari semua sains. Dalam buku yang telah tersedia tidak ada bahan ajar tematik yang terintegrasi dengan Al-Quran, dan Hadits, serta nilai-nilai Islam yang mampu mengimplementasikan kompetensi inti dari kurikulum 2013 yaitu kompetensi sikap spiritual dalam pembelajaran tematik. Perumusan penelitian ini yaitu: (1) menghasilkan bahan ajar tematik berbasis nilai keislaman tema 7 (Kepemimpinan) kelas 6 Madrasah Ibtidaiyah Negeri 2 Jember. (2) mengetahui efektifitas bahan ajar tematik berbasis nilai-nilai keislaman dalam pembelajaran. Penelitian ini menggunakan jenis penelitian pengembangan Research and Development, model Borg and Gall yang terbagi menjadi 10 langkah, yaitu: (1) penelitian dan pengumpulan data (2) perencanaan, (3) pengembangan draf produk, (4) uji coba lapangan awal, (5) merevisi hasil uji coba, (6) uji coba lapangan, (7) penyempurnaan produk hasil uji lapangan, (8) uji pelaksanaan lapangan, (9) penyempurnaan produk hasil, dan (10) diseminasi dan implementasi. Teknik uji coba dilakukan dengan membandingkan nilai pre-test dan post-test. Data dihitung dengan uji-t dan diolah menggunakan aplikasi SPSS untuk mengetahui efektifitas bahan ajar. Hasil penelitian ini menunjukkan: uji validasi tersebut rata-rata menghasilkan 88,79 % dengan kriteria bahwa buku tersebut sangat layak untuk digunakan dalam pembelajaran. Dari segi kemenarikan, buku ini sangat menarik untuk digunakan pada siswa, hal ini berdasarkan dari hasil data angket yang diberikan kepada siswa dengan rata-rata 88,24% dengan kualifikasi sangat menarik. Sedangkan dari hasil pre-test dan pos-test berdasarkan uji t hitung yang menunjukan lebih besar dari t tabel, berarti buku tersebut efektif untuk digunakan dalam pembelajaran. Kata Kunci: Bahan Ajar; Pembelajaran Tematik; Nilai Keislaman

scholarly journals A NEW METHOD OF PERFORMING FIELD TRIALS

1969 ◽  
Vol 28 (1) ◽  
pp. 22-34
Author(s):  
Bernardo G. Capó
Keyword(s):  
Field Experiments ◽  
Field Tests ◽  
Field Trials ◽  
New Method ◽  
Numerical Example ◽  
Fertilizer Experiment ◽  
Treatment Experiment

A new method of performing field experiments with relatively small numbers of treatments is described. The requirement to be fulfilled by the layouts of such field tests is specified and examples of possible designs for a 5-treatment experiment are illustrated. The theory of the procedure of calculation is discussed and a numerical example of said calculations is furnished in connection with the interpretation of a fertilizer experiment performed with cotton.

scholarly journals Extract of Nicotiana tabacum as a potential control agent of Grapholita molesta (Lepidoptera: Tortricidae)

2018 ◽  
Author(s):  
Souvic Sarker ◽  
Un Taek Lim
Keyword(s):  
Nicotiana Tabacum ◽  
Acute Toxicity ◽  
Control Agent ◽  
Oriental Fruit Moth ◽  
Grapholita Molesta ◽  
Potential Control ◽  
Residual Toxicity ◽  
First Instar ◽  
Pome Fruits ◽  
Important Pest

Oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), is an important pest of stone and pome fruits. Growers usually depend on chemical insecticides to control this pest, but demand for more environmentally-friendly means of controlling pests is increasing. At least 77 plant extracts have been reported to be effective against other lepidopterans, but their acute toxicity against G. molesta has rarely been studied. Among these 77 materials, we assessed the residual toxicity of 32 extracts against first instar larvae (

Field tests of an experimental helicopter time‐domain electromagnetic system for unexploded ordnance detection

Geophysics ◽  
2004 ◽  
Vol 69 (3) ◽  
pp. 664-673 ◽  
Author(s):  
Les P. Beard ◽  
William E. Doll ◽  
J. Scott Holladay ◽  
T. Jeffrey Gamey ◽  
James L.C. Lee ◽  
...  
Keyword(s):  
Time Domain ◽  
Eddy Currents ◽  
Field Tests ◽  
Field Trials ◽  
Unexploded Ordnance ◽  
Signal Attenuation ◽  
Signal To Noise ◽  
Electromagnetic System ◽  
Time Domain Electromagnetic ◽  
Unexploded Ordnance Detection

Field trials of a low‐flying time‐domain helicopter electromagnetic system designed for detection of unexploded ordnance have yielded positive and encouraging results. The system is able to detect ordnance as small as 60‐mm rounds at 1‐m sensor height. We examined several transmitter and receiver configurations. Small loop receivers gave superior signal‐to‐noise ratios in comparison to larger receiver loops at low heights. Base frequencies of 90 Hz and 270 Hz were less affected than other base frequencies by noise produced by proximity to the helicopter and by vibration of the support structure. For small ordnance, a two‐lobed, antisymmetric transmitter loop geometry produced a modest signal‐to‐noise enhancement compared with a large single rectangular loop, presumably because the antisymmetric transmitter produces smaller eddy currents in the helicopter body, thereby reducing this source of noise. In most cases, differencing of vertically offset receivers did not substantially improve signal‐to‐noise ratios at very low sensor altitudes. Signal attenuation from transmitter to target and from target to receiver causes signals from smaller ordnance to quickly become indistinguishable from geological background variations, so that above a sensor height of about 3 m only large ordnance items (e.g., bombs and large caliber artillery rounds) were consistently detected.

From Science to Practice: Improving ROP by Utilizing a Cloud-Based Machine-Learning Solution in Real-Time Drilling Operations

2021 ◽  
Author(s):  
Kriti Singh ◽  
Sai Yalamarty ◽  
Curtis Cheatham ◽  
Khoa Tran ◽  
Greg McDonald
Keyword(s):  
Machine Learning ◽  
Real Time ◽  
Situational Awareness ◽  
Field Tests ◽  
Field Trials ◽  
Permian Basin ◽  
Lateral Vibrations ◽  
Drilling Parameters ◽  
Drilling Conditions ◽  
Performance Results

Abstract This paper is a follow up to the URTeC (2019-343) publication where the training of a Machine Learning (ML) model to predict rate of penetration (ROP) is described. The ML model gathers recent drilling parameters and approximates drilling conditions downhole to predict ROP. In real time, the model is run through an optimization sweep by adjusting parameters which can be controlled by the driller. The optimal drilling parameters and modeled ROP are then displayed for the driller to utilize. The ML model was successfully deployed and tested in real time in collaboration with leading shale operators in the Permian Basin. The testing phase was split in two parts, preliminary field tests and trials of the end-product. The key learnings from preliminary field tests were used to develop an integrated driller's dashboard with optimal drilling parameters recommendations and situational awareness tools for high dysfunction and procedural compliance which was used for designed trials. The results of field trials are discussed where subject well ROP was improved between 19-33% when comparing against observation/control footage. The overall ROP on subject wells was also compared against offset wells with similar target formations, BHAs, and wellbore trajectories. In those comparisons against qualified offsets, ROP was improved by as little as 5% and as much as 33%. In addition to comparing ROP performance, results from post-run data analysis are also presented. Detailed drilling data analytics were performed to check if using the recommendations during the trial caused any detrimental effects such as divergence in directional trends or high lateral or axial vibrations. The results from this analysis indicate that the measured downhole axial and lateral vibrations were in the safe zone. Also, no significant deviations in rotary trends were observed.

Intentionally Deadheading SAGD ESPs - An Unconventional Approach to Improve Run Life

2021 ◽  
Author(s):  
J. Daine Studer ◽  
Jesus E. Chacin ◽  
Roger Walters ◽  
Hoai Ann Nguyen
Keyword(s):  
Fiber Optics ◽  
Field Tests ◽  
Field Trials ◽  
Base Line ◽  
Cooling Rates ◽  
Temperature Changes ◽  
Plant Maintenance ◽  
High Cooling Rates ◽  
Log Normal ◽  
Log Normal Distribution

Abstract SAGD ESPs run at the highest motor temperatures current technology allows. However, they cool very rapidly when shutdown. High cooling rates promote motor oil volumetric contraction, eventually leading to wellbore fluid ingress and short-circuited motors. The Paper presents successful field tests designed to decrease ESP cooling rates by inducing controlled deadheads, rather than shutting down ESPs. Various extended deadhead field trials (up to 70+ days duration) validated the approach, while confirming that no deadhead related ESP damage was induced. ESP temperature changes were measured using fiber optics strings installed as part of the usual completion in 60+ wells, during a four week-long field-wide plant maintenance turn-around. While cooling rates varied somewhat from well to well, they all showed very similar behavior and were very well fitted with a log-normal distribution, R2factor &gt; 95%. Most ESP temperatures decreased between 50°C to 120°C in a week. This data was used as a general baseline to support the deadheading field trials. An ESP was fitted internally with an RTD at the base of the motor and externally with a clamped fiber optics string. This ESP was operated normally at 55 Hz for a few months. An 8-hour shut down test established an initial base line cooling rate of 6.6°C/hour. Subsequent 6-hour deadhead tests at 30Hz and 45 Hz showed decreased cooling rates of 4.0°C/hour and 2.2°C/hour, respectively. This result clearly established the potential to deadhead at different frequencies to obtain different lower cooling rates. Finally, two extended deadhead tests (3 and 10 weeks in duration) were executed to help determine if it was possible to induce damage in SAGD ESPs by deadheading, as is usually the case in most non-thermal applications. These ESPs operated normally after the extended tests and one was dismantled upon failure, looking for any signs of deadhead damage. Results presented show that deadheading SAGD ESPs provides the opportunity to safely minimize ESP thermal cycles, which could lead to a significant improvement in ESP run life.

Developing a census method based on sight counts to estimate rabbit (Oryctolagus cuniculus) numbers

2003 ◽  
Vol 30 (5) ◽  
pp. 487 ◽  
Author(s):  
Dylan W. Poole ◽  
Dave P. Cowan ◽  
Graham C. Smith
Keyword(s):  
Population Size ◽  
Field Trials ◽  
Population Estimates ◽  
Economic Costs ◽  
Natural Conditions ◽  
Commercial Farms ◽  
The Mean ◽  
The Difference ◽  
Study Sites ◽  
Autumn And Winter

A rabbit-census method, based on systematic counts conducted at night or at dawn and dusk, was developed and validated in terms of estimating the total number of rabbits present in a given area. Initially, models were developed under semi-natural conditions to describe the relationships between the numbers of rabbits counted and population size. Confidence limits were also calculated. The models were developed by comparing rabbit counts with the actual number of rabbits present, from a known population of animals. Only spotlight counts at night were considered reliable enough to estimate rabbit population size. During the autumn and winter months these represented ~60% of the population present. The model was subsequently validated, in two different exercises, following a series of field trials conducted under a variety of conditions on commercial farms. Initially, population estimates derived from the model were compared with those calculated using an alternative census technique. Population estimates, using the two techniques, were very similar at nine of the ten study sites. A second validation exercise was also conducted whereby the number of rabbits removed at each of the sites was compared with the difference between the mean pre- and post-removal spotlight counts. The results further supported the proposition that spotlight counts represent ~60% of the population present, with the difference between the two mean spotlight counts representing 61.2% (± 11.0, s.d.) of the number of rabbits removed. The census method therefore shows considerable promise as a means to estimate rabbit numbers under a range of agricultural conditions and therefore has the potential to predict accurately the economic costs of rabbit damage and also to gauge the effectiveness of various methods of rabbit control.

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