Field assessment of a pulse width modulation (PWM) spray system applying different spray volumes: duty cycle and forward speed effects on vines spray coverage

AbstractThe pulse width modulation (PWM) spray system is the most advanced technology to obtain variable rate spray application without varying the operative sprayer parameters (e.g. spray pressure, nozzle size). According to the precision agriculture principles, PWM is the prime technology that allows to spray the required amount where needed without varying the droplet size spectra which benefits both the uniformity of spray quality and the spray drift reduction. However, some concerns related to the effect of on–off solenoid valves and the alternating on/off action of adjacent nozzles on final uneven spray coverage (SC) have arisen. Further evaluations of PWM systems used for spraying 3D crops under field conditions are welcomed. A tower-shaped airblast sprayer equipped with a PWM was tested in a vineyard. Twelve configurations, combining duty cycles (DC: 30, 50, 70, 100%) and forward speeds (FS: 4, 6, 8 km h−1), were tested. Two methodologies, namely field-standardized and real field conditions, were adopted to evaluate the effect of DC and FS on (1) SC variability (CV%) along both the sprayer travel direction and the vertical spray profile using long water sensitive papers (WSP), and (2) SC uniformity (IU, index value) within the canopy at different depths and heights, respectively. Furthermore, the SC (%) and deposit density (Nst, no stains cm−2), determined using short WSP, were used to evaluate the spray application performances taking into account the spray volumes applied. Under field-controlled conditions, the pulsing of the PWM system affects both the SC variability measured along the sprayer travel direction and along the vertical spray profile. In contrast, under real field conditions, the PWM system does not affect the uniformity of SC measured within the canopy. The relationship between SC and Nst allowed identification of the ranges of 200–250 and 300–370 l ha−1 as the most suitable spray volumes to be applied for insecticide and fungicide plant protection products, respectively.

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Use of Modern Digital Technologies in Agriculture in Slovenia

MARDS Workshop Proceedings ◽

10.18690/978-961-286-409-5.5 ◽

2020 ◽

pp. 39-44

Author(s):

Denis Stajnko

Keyword(s):

Precision Agriculture ◽

Weed Management ◽

Pulse Width Modulation ◽

Plant Protection ◽

Digital Technologies ◽

Plant Protection Products ◽

Doctoral Study ◽

Current State ◽

Study Programme ◽

Electro Magnetic

The presentation summarises the development and current state-of-the-art of the Doctoral Study Programme ‘Agriculture’, and researches carried out in the Faculty of Agriculture Life Sciences in the field of the use of modern digital technologies in precision agriculture, such as the application of image analysis for fruit yield estimation. A second important topic represents the reduction of plant protection products in orchards, which is based on 3D tree reconstruction with LIDAR (Laser Detection and Ranging) and EMV (Electro Magnetic Valve) triggering in pulse width modulation. First experiments towards a future self-guided tractor driving, spraying or weed management by simply navigating a field robot has already been developed and tested.

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Comparison of Spray Configurations in a Spray Cabin Design for Ornamental Potted Plants: A Proof-of-Concept Study

Transactions of the ASABE ◽

10.13031/trans.11383 ◽

2017 ◽

Vol 60 (3) ◽

pp. 647-656 ◽

Cited By ~ 1

Author(s):

Ingrid Zwertvaegher ◽

Dieter Foqué ◽

Donald Dekeyser ◽

Stephanie Van Weyenberg ◽

David Nuyttens

Keyword(s):

Integrated Pest Management ◽

Pest Management ◽

Plant Protection ◽

Spray Deposition ◽

Crop Protection ◽

Plant Protection Products ◽

Proof Of Concept ◽

Spray Application ◽

Concept Study ◽

Potted Plants

Abstract. With the implementation of integrated pest management in the European Union, growers are obliged to manage pests in a manner that minimizes health and environmental risks due to the use of plant protection products. Among other approaches, this goal can be achieved by optimizing spray application techniques. As an alternative to the predominantly used handheld equipment, such as spray guns, spray boom systems might substantially improve spray application, and thus crop protection management, in greenhouses. The aim of this proof-of-concept study was to compare different spray configurations in a spray cabin designed to spray ornamental potted plants that are moving on a conveyor belt. Seven different spray configurations were examined for optimal spray deposition in two crops (azalea and ivy) using mineral chelate tracers. The deposition tests showed that the presented prototype can satisfactorily spray potted plants up to a height of 25 cm including the pot height. The best spray deposition was found with two flat-fan nozzles oriented 35° upward, spraying at 1.0 bar and an application rate of 1047 L ha-1. This configuration increased deposition on the underside of the leaves and at the middle foliage layer compared to the other configurations that were evaluated. The spray cabin with a band spray setting has potential to mitigate the use of plant protection products and achieve a more efficient spray application compared to traditional handheld techniques and broadcast spray boom techniques. Keywords: Crop protection, Integrated pest management, Nozzle type, Spray deposition.

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Design and Experiment of a Variable Spray System for Unmanned Aerial Vehicles Based on PID and PWM Control

Applied Sciences ◽

10.3390/app8122482 ◽

2018 ◽

Vol 8 (12) ◽

pp. 2482 ◽

Cited By ~ 9

Author(s):

Sheng Wen ◽

Quanyong Zhang ◽

Jizhong Deng ◽

Yubin Lan ◽

Xuanchun Yin ◽

...

Keyword(s):

Pulse Width Modulation ◽

Insect Pests ◽

Plant Protection ◽

Plant Diseases ◽

Sensor Technology ◽

Target Area ◽

Square Wave ◽

Spray System ◽

Duty Cycles ◽

Aerial Vehicle

Unmanned aerial vehicle (UAV) variable-rate spraying technology, as the development direction of aviation for plant protection in the future, has been developed rapidly in recent years. In the actual agricultural production, the severity of plant diseases and insect pests varies in different locations. In order to reduce the waste of pesticides, pesticides should be applied according to the severity of pests, insects and weeds. On the basis of explaining the plant diseases and insect pests map in the target area, a pulse width modulation variable spray system is designed. Moreover, the STMicroelectronics-32 (STM32) chip is invoked as the core of the control system. The system combines with sensor technology to get the prescription value through real-time interpretation of prescription diagram in operation. Then, a pulse square wave with variable duty cycles is generated to adjust the flow rate. A closed-loop Proportional-Integral-Derivative (PID) control algorithm is used to shorten the time of system reaching steady state. The results indicate that the deviation between volume and target traffic is stable, which is within 2.16%. When the duty cycle of the square wave is within the range of 40% to 100%, the flow range of the single nozzle varies from 0.16 L/min to 0.54 L/min. Variable spray operation under different spray requirements is achieved. The outdoor tests of variable spray system show that the variable spray system can adjust the flow rapidly according to the prescription value set in the prescription map. The proportion of actual droplet deposition and deposition density in the operation unit is consistent with the prescription value, which proves the effectiveness of the designed variable spray system.

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Assessment of the impacts of microbial plant protection products containing Bacillus thuringiensis on the survival of adults and larvae of the honeybee (Apis mellifera)

Environmental Science and Pollution Research ◽

10.1007/s11356-021-12446-3 ◽

2021 ◽

Author(s):

Charlotte Steinigeweg ◽

Abdulrahim T. Alkassab ◽

Hannes Beims ◽

Jakob H. Eckert ◽

Dania Richter ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Plant Protection ◽

Plant Protection Products ◽

Field Conditions ◽

Test Duration ◽

Oral Toxicity ◽

Feeding Study ◽

Laboratory Conditions ◽

Pollen Feeding ◽

Contamination Levels

AbstractThis study was aimed at evaluating the effect of a microbial pest-controlling product (MPCP) with the active substance Bacillus thuringiensis ssp. aizawai (strain: ABTS-1857) on adults and larvae of honeybees. To determine the contamination levels of Bt spores in different matrices, a colony-feeding study under semi-field conditions was performed. Furthermore, two chronic adult trials and a chronic larval study were conducted under laboratory conditions to test the effects of different concentrations of the plant protection product (PPP) on the development and mortality. Possible modifications of the chronic oral toxicity test were assessed by additional pollen feeding. Our results showed that Bt spores were detected in all matrices over the entire test duration in different concentrations, decreasing over time. The survival of adult bees and larvae was negatively affected in laboratory conditions after a chronic exposure to the MPCP depending on the tested concentrations. Moreover, the earliest sign of bee mortality, resulting from exposure to ABTS-1857, was recorded only after 96 h at the highest tested concentration. Pollen feeding to adults significantly increased the survival of the treated bees. In conclusion, the PPP with the Bt strain ABTS-1857 showed an effect on the mortality of adults and larvae under laboratory conditions. Further studies with Bt-based PPPs under realistic field conditions are necessary to evaluate the potential risk of those MPCPs on honeybees.

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Field Performance Evaluation of Pulse-Width Modulation and Pressure-Controlled, Fixed-Orifice Application Systems for Sensor-Based Nitrogen Applications

Applied Engineering in Agriculture ◽

10.13031/aea.14289 ◽

2021 ◽

Vol 37 (3) ◽

pp. 467-480

Author(s):

Jackson S Stansell ◽

Samantha L Teten ◽

Samuel E Marx ◽

Joe D Luck

Keyword(s):

Precision Agriculture ◽

Pulse Width ◽

Pulse Width Modulation ◽

Field Performance ◽

List Type ◽

Technological Advancement ◽

N Application ◽

Application Systems ◽

Operational Variables ◽

Pressure Controlled

HighlightsComparison of PC system and PWM system in-field performance indicated that the PWM system made sensor-based N applications more accurately than the PC system.The turndown ratio calculated from the aggregate application instances was 6.2:1.For both the PWM system and the PC system, applications were made more accurately when 28% UAN was applied rather than 32% UAN. Abstract. Sensor-based nitrogen (N) applications have shown promise for improving N use efficiency, but present significant challenges for application rate control due to highly variable and frequently changing target rates. If applications are to be made precisely, equipment systems used for sensor-based N applications must be designed to meet system demands. Pulse-width modulation (PWM) equipped systems have emerged as a technological advancement over traditional pressure-controlled (PC) systems for improving variable rate N application accuracy. Little research, however, has been done to assess the performance of PWM systems during sensor-based N applications in-field. This work analyzed as-applied data collected from in-field sensor-based N applications with pressure-controlled (PC) and PWM systems in Nebraska between 2015 and 2017 to quantify system requirements, assess system performance, and determine performance impacting operational variables. It was found that systems should be capable of 1-s rate changes of ±71.1 L ha-1 (7.6 gpa), 1-s flow rate changes of ±11.4 L min-1 (3 gpm), and turndown ratios of at least 6:1. PWM systems achieved application rates within 10% of the target rate 10% more often than PC systems, and showed less variability in application error. However, PWM systems still demonstrated significant application errors with an observed RMSE of 44.9 L ha-1 (4.8 gpa). Speed change magnitude was found to be most associated with increases in percent application error. These findings substantiate that PWM systems effectively improve sensor-based N application accuracy versus traditional PC systems. However, collaborative efforts toward greater cohesion between sensor-based application expectations and application equipment capabilities are necessary for maximizing the effectiveness of sensor-based N applications. Keywords: Precision agriculture, Rate controllers, Site-specific crop management, Sprayer, Turndown ratio.

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A Small Versatile Electrical Robot for Autonomous Spraying in Agriculture

AgriEngineering ◽

10.3390/agriengineering1030029 ◽

2019 ◽

Vol 1 (3) ◽

pp. 391-402 ◽

Cited By ~ 4

Author(s):

Cantelli ◽

Bonaccorso ◽

Longo ◽

Melita ◽

Schillaci ◽

...

Keyword(s):

Precision Agriculture ◽

Management System ◽

Agricultural Sector ◽

Plant Protection ◽

Autonomous Vehicle ◽

Plant Protection Products ◽

Labor Costs ◽

Innovative Solution ◽

The Right ◽

High Degree

Boosting innovation and research in the agricultural sector is crucial if farmers are asked to produce more with less. Precision agriculture offers different solutions to assist farmers in improving efficiency and reducing labor costs while respecting the legal requirements. Precision spraying enables the treatment of only the plants that require it, with the right amount of products. Our research group has developed a solution based on a reconfigurable vehicle with a high degree of automation for the distribution of plant protection products in vineyards and greenhouses. The synergy between the vehicle and the spraying management system we developed is an innovative solution with high technological content, and attempts to account for the current European and global directives in the field of agricultural techniques. The objectives of our system are the development of an autonomous vehicle and a spraying management system that allows safe and accurate autonomous spraying operations.

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Mineral-Ecological Cropping Systems—A New Approach to Improve Ecosystem Services by Farming without Chemical Synthetic Plant Protection

Agronomy ◽

10.3390/agronomy11091710 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1710

Author(s):

Beate Zimmermann ◽

Ingrid Claß-Mahler ◽

Moritz von Cossel ◽

Iris Lewandowski ◽

Jan Weik ◽

...

Keyword(s):

Ecosystem Services ◽

Precision Agriculture ◽

Energy Use ◽

Plant Protection ◽

Cropping Systems ◽

Mineral Fertilizer ◽

Plant Protection Products ◽

Agricultural Landscapes ◽

Ongoing Research ◽

Provisioning Ecosystem Services

The search for approaches to a holistic sustainable agriculture requires the development of new cropping systems that provide additional ecosystem services beyond biomass supply for food, feed, material, and energy use. The reduction of chemical synthetic plant protection products is a key instrument to protect vulnerable natural resources such as groundwater and biodiversity. Together with an optimal use of mineral fertilizer, agroecological practices, and precision agriculture technologies, a complete elimination of chemical synthetic plant protection in mineral-ecological cropping systems (MECSs) may not only improve the environmental performance of agroecosystems, but also ensure their yield performance. Therefore, the development of MECSs aims to improve the overall ecosystem services of agricultural landscapes by (i) improving the provision of regulating ecosystem services compared to conventional cropping systems and (ii) improving the supply of provisioning ecosystem services compared to organic cropping systems. In the present review, all relevant research levels and aspects of this new farming concept are outlined and discussed based on a comprehensive literature review and the ongoing research project “Agriculture 4.0 without Chemical-Synthetic Plant Protection”.

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Advancements of Spraying Technology in Agriculture

10.5772/intechopen.98500 ◽

2021 ◽

Author(s):

Fiaz Ahmad ◽

Aftab Khaliq ◽

Baijing Qiu ◽

Muhammad Sultan ◽

Jing Ma

Keyword(s):

Environmental Protection ◽

Precision Agriculture ◽

Crop Production ◽

Plant Protection ◽

Experimental Studies ◽

Plant Protection Products ◽

Point Of View ◽

Utilization Rate ◽

Design Development ◽

Pesticide Application

Plant protection activities are most important practices during crop production. Application of maximum pesticide products with the sprayer. The application of fungicides, herbicides, and insecticides is one of the most recurrent and significant tasks in agriculture. Conventional agricultural spraying techniques have made the inconsistency between economic growth and environmental protection in agricultural production. Spraying techniques continuously developed in recent decades. For pesticide application, it is not the only sprayer that is essential, but all the parameters like the type and area of the plant canopy, area of a plant leaf, height of the crop, and volume of plants related to plant protection product applications are very important for obtaining better results. From this point of view, the advancement in agriculture sprayer has been started in last few decades. Robotics and automatic spraying technologies like variable rate sprayers, UAV sprayers, and electrostatic sprayers are growing to Increase the utilization rate of pesticides, reduce pesticide residues, real-time, cost-saving, high compatibility of plant protection products application. These technologies are under the “umbrella” of precision agriculture. The mechanized spraying system, usually implemented by highly precise equipment or mobile robots, which, makes possible the selective targeting of pesticide application on desire time and place. These advanced spraying technologies not only reduces the labour cost but also effective in environmental protection. Researchers are conducting experimental studies on the design, development and testing of precision spraying technologies for crops and orchards.

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The 1-Bit Instrument

Journal of Sound and Music in Games ◽

10.1525/jsmg.2020.1.1.44 ◽

2020 ◽

Vol 1 (1) ◽

pp. 44-74

Author(s):

Blake Troise

Keyword(s):

Pulse Width ◽

Pulse Width Modulation ◽

Interleaving Techniques ◽

Sonic Environment

The 1-bit sonic environment (perhaps most famously musically employed on the ZX Spectrum) is defined by extreme limitation. Yet, belying these restrictions, there is a surprisingly expressive instrumental versatility. This article explores the theory behind the primary, idiosyncratically 1-bit techniques available to the composer-programmer, those that are essential when designing “instruments” in 1-bit environments. These techniques include pulse width modulation for timbral manipulation and means of generating virtual polyphony in software, such as the pin pulse and pulse interleaving techniques. These methodologies are considered in respect to their compositional implications and instrumental applications.

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