Operation Of Sprayer Research Articles

Use of models to assess the reduction in contamination of water bodies by agricultural pesticides through the implementation of policy instruments: a case study of the Voluntary Initiative in the UK

Through normal agricultural use, pesticides may reach environmental water bodies via several routes of entry. Various policies and initiatives exist to reduce the effects of pesticides in the environment. One such initiative in place in the UK is the Voluntary Initiative (VI). The VI is a voluntary scheme put forward by the Crop Protection Association with other crop protection and farming organisations to reduce the environmental impacts of pesticides. Mathematical models of pesticide fate can usefully be applied to examine the impact of factors influencing the contamination of water bodies by pesticides. The work reported here used water quality models to examine how changes in farmer behaviour could potentially impact pesticide contamination of environmental water bodies. As far as possible, uncalibrated, standard regulatory models were used. Where suitable models were not available, simple models were defined for the purposes of the study and calibrated using literature data. Scenarios were developed to represent different standards of practice with respect to pesticide user behaviour. The development of these scenarios was guided by the Crop Protection Management Plan (CPMP) aspect of the VI. A framework for the use of modelling in the evaluation of the VI is proposed. The results of the modelling study suggest that, in several areas, widespread adoption of the measures proposed in the VI could lead to reductions in pesticide contamination of environmental water bodies. These areas include pesticide contamination from farmyards, spray drift and field runoff. In other areas (including pesticide leaching to groundwater and contamination of surface water from field drains) the benefits that may potentially be gained from the VI are less clear. A framework to evaluate the VI should take into consideration the following aspects: (1) groundwater is more at risk when there is a combination of leachable compounds, vulnerable soils, shallow groundwater and high product usage; (2) surface water contamination from drains is most likely when heavy rain falls soon after application, the soils are vulnerable and product usage is high; (3) surface water contamination from drift is most likely when the distance between the spray boom and water body is small and product usage is high; (4) surface water contamination from farmyards is dependent on the nature of the farmyard surface, the competence of the spray operator and the level of product usage. Any policy or initiative to reduce pesticide contamination should be measured against farmer behaviour in these areas.

Evaluation Aspects for Ecological Risk in Operation of Field Sprayers

Intensive agricultural production is closely linked with the application of plant protection means, as well as use of field sprayers. When intensive technologies are used, crops as are treated with pesticides several times during the vegetation period. All chemicals applied for plant protection are more or less dangerous to human health and environment. Particularly dangerous is the use of unchecked and defective field sprayers, non-observance of the stated rates of pesticides, agrotechnical treatment terms, as well as wrong adjustment of the sprayers. Standard ISO 14001 states the basic measures for establishment and maintenance of environmental management system. In the article is presented the model of environmental management system for field sprayers based on given standard. The evaluation system includes technical and organizational measures having an influence on the pollution of environment and human health. This system includes the analysis of the factors, planning, regular inspection of field sprayers, training of serving staff and the corrective measures. During the operation of field sprayers the local atmospheric, ground, and water pollution is to be observed that in its turn is conductive to the choking up of agricultural field crop and animal products. The levels of ecological risk include the accumulation of pesticides into environment, as well as ecological risk connected with the increased human morbidity and disappearance of individual species of plants and animals. Proposed environmental management system for field sprayers can serve as a basis to develop and introduce the system of periodical inspections for field sprayers. The environmental management system for field sprayers will promote more effective protection of people and environment.

Persistence of chlorpyrifos, diazinon and dimethoate sprayed in the greenhouse environment during hydroponic cultivation of Gerbera

The fate and behavior of chlorpyrifos, diazinon and dimethoate in a greenhouse installation during hydroponic cultivation of Gerbera was investigated. Their concentrations in the greenhouse air were related to their physicochemical properties. Thus, diazinon exhibited the highest concentration in the greenhouse air 2 hours after application, while chlorpyrifos and dimethoate were measured at lower concentrations. Afterwards, a rapid decrease was recorded. The concentrations of the above pesticides in the drain water of the open hydroponic system were relatively high immediately after the application but decreased rapidly during the following 3 days. In the closed hydroponic system, all the pesticides were accumulated in the nutrient solution during the first 24 hours after application but their concentration slowly decreased over the following 3 days. The highest concentrations of chlorpyrifos and diazinon were measured on the head of the spray operator. However, the highest concentration of dimethoate was measured on his chest.

Performance Evaluation of Different Spraying Systems in Mango orchard

Three different spraying systems namely, tractor operated aero blast sprayer, power knapsack sprayer and manually operated rocker sprayer were evaluated in laboratory and in a mango orchard to study their performance in terms of size Of droplets and their distribution, penetration capability of spray droplets into the canopy, application rate, field capacity, vertical reach of spray, man-power requirement, fuel consumption and cost of operation. The tractor operated aero blast sprayer was found to produce smallest droplet size (254 µ) with better penetration of spray droplets into the canopy, highest field capacity (1.54 ha/hr) with lowest man-power requirement (1.95 man-hr/ha). The maximum height of reach of the spray of 6.70 m from this sprayer was also sufficient to cover the full height of mango trees. Though the cost of operation of aero blast sprayer (Rs. 197.19/ha) was much higher than that of manual rocker sprayer (Rs. 42.26/ha), the former could be recommended for use in large and small-scale medium height orchards on· individual ownership or custom-hire basis in view of its better performance.

Segurança no trabalho com agrotóxicos em citros: aplicação com o turbopulverizador e preparo de calda em tanque de 2.000 L

Os objetivos deste trabalho foram quantificar as exposições dérmicas e respiratórias proporcionadas pelas condições de trabalho na aplicação de agrotóxicos em cultura de citros com o turbopulverizador e no preparo de caldas em um tanque de 2.000 L de capacidade; avaliar a eficiência de medidas de proteção individual; determinar as regiões mais expostas do corpo dos trabalhadores e coletiva para esses trabalhadores; e classificar as condições de trabalho, sem e com as medidas de proteção testadas, quanto à segurança ocupacional das recomendações de agrotóxicos registrados para o controle das principais pragas e doenças dessa cultura. Verificou-se, que para o tratorista e para o aplicador, pulverizando agrotóxicos em citros com o turbopulverizador, as medidas de proteção mais eficientes foram o conjunto AZR e a cabina Real. O conjunto AZR foi eficiente no controle da exposição do preparador de caldas, pois foi suficiente para tornar condições de trabalho inseguras em seguras. A região mais exposta do corpo, nas duas condições de trabalho estudadas, foram as mãos dos trabalhadores.

DISTANCE–BASED CONTROL SYSTEM FOR MACHINE VISION–BASED SELECTIVE SPRAYING

For effective operation of a selective sprayer with real–time local weed sensing, herbicides must be delivered accurately to weed targets in the field. With a machine vision–based selective spraying system, acquiring sequential images and switching nozzles on and off at the correct locations are critical. An MS Windows–based imaging system was interfaced with a real–time embedded selective spray controller system to accomplish control tasks based on distance traveled. A machine vision–based sensing system and selective herbicide control system was developed and installed on a sprayer. A finite state machine (FSM) model was employed for controller design, and general design specifications were developed for determining the travel distance between states. The spatial application accuracy of the system was measured in the field using artificial targets. The system operated with an overall hit accuracy of 91% with no statistical evidence of hit accuracy or mean pattern length being dependent on vehicle speed. Significant differences in pattern length variance and mean pattern width were detected across speed levels ranging from 3.2 to 14 km/h. Spray patterns tended to shift relative to the target at higher travel speeds.

Pest management challenges for smallholder vegetable farmers in Zimbabwe

Smallholder vegetable production is expanding rapidly in Zimbabwe both for local sale in urban markets and for export. Pest management practices of 12 small-scale vegetable farmers in two areas of Zimbabwe were surveyed over a five-month period to gather information on crops, pests, diseases and crop protection methods. A range of serious pests and diseases affects non-indigenous vegetables such as Brassicas, tomatoes, onions and cucurbits. Although farmers use some cultural control methods and occasionally botanical pesticides, pest control is predominantly by the use of conventional synthetic pesticides. These are usually applied through lever operated knapsack sprayers although some less orthodox application methods are occasionally used. Results are variable and there are concerns about risks to sprayer operators, consumers and the environment (including natural enemies) due to shortcomings in protective clothing, large deviations from recommended doses and excessive run-off to the soil. Field trials were carried out to evaluate a modified sprayer lance which directs the spray upwards rather than downwards in an attempt to place more of the spray under the leaves where most of the arthropod pests are found. The ‘V lance’ as it is called improved the uniformity of spray coverage on the upper and lower leaf surfaces and is expected to improve efficacy of spraying and/or offer the opportunity to reduce doses or spray frequencies. Farmers who tested the device reported good results and gave constructive feedback for future improvements. The smallholder vegetable sector requires support in the form of improved access to existing pest management information (in an appropriate form) and focused research targeted at the knowledge gaps which currently impede implementation of sustainable IPM.

Comparison of spray operator exposure during orchard spraying with hand-held equipment fitted with standard and air injector nozzles

A field study using a patch method to assess operator exposure showed that compared to standard cone nozzles, spraying with air injection nozzles reduced exposure. The results indicate that this nozzle type deserves consideration as an efficient and economic contribution to safe application of plant protection products.

AUTONOMOUS SPEED SPRAYER GUIDANCE USING MACHINE VISION AND FUZZY LOGIC

A Fuzzy Logic Controller (FLC) was developed for autonomous operation of a speed sprayer in an orchard. The operation of the FLC was graphically simulated under the real condition of the orchard. Machine vision was used to determine vehicle heading and four ultrasonic sensors were used to detect obstacles during the operation. Operation time duration of the hydraulic cylinders was inferred as output of the FLC. The results of simulation showed that the speed sprayer could be operated autonomously by the FLC that used sensor inputs from machine vision and ultrasonic sensors. After the graphic simulation, autonomous speed sprayer operation in a real orchard was conducted using the developed FLC. Orchard image analysis and signals of ultrasonic sensors were processed in real time. The speed sprayer was modified to be steered by two hydraulic cylinders. The results of field test showed that the speed sprayer could be operated by the FLC. The ultrasonic sensors didn’t contribute to the improvement of guidance performance; however, they assisted the speed sprayer to avoid trees or obstacles in emergent situations.

COSTO ENERGETICO DE LAS OPERACIONES AGRICOLAS MECANIZADAS MAS COMUNES EN CHILE

A study was conducted whose objectives were to establish the energy cost of the principal mechanized agricultural operations in Chile and compare the costs of the different sizes of machines sold in the country, testing the hypothesis that the energy cost of an operation is independent from the size of the equipment. Hourly costs /MJ/h), costs per worked area (MJ/ha) and per mass processed (MJ/T) were calculated adding up the energy sequestered in the construction materials, manufacturing, transport, fuel, lubricants, filters, repairs, maintenance, and in the labor needed to operate the machines. The values per worked area and mass processed were calculated using the work capacity of the machines. The results showed that the largest energy costs corresponded to the operation of choppers, foggers, grain harvesters and plows. The smallest costs corresponded to the operation of centrifugal fertilizers and boom sprayers. The hourly energy costs depend upon the machine sizes but the costs per worked area or mass processed are independent of such sizes.

Evaluation of Bacillus Thuringiensis Insecticides Against Dbm, 1994

Abstract The insecticide was evaluated at the Kula Research Station, Maui Agricultural Park, from October to December. The field was set up in a RCB design with six treatments and four replications (blocks). Each treatment plot measured 70 ft. by 7.5 ft. It consisted of four rows of cabbage on 36 in. centers and 18 in. in-row spacing. Adjacent rows were offset to allow equidistant plant spacing between rows. Treatments were applied using a tractor mounted with a PTO driven spray pump equipped with a 30 ft boom. The boom was set with three banks of hollow cone nozzles (TX-26, Spraying Systems) that coincided with row spacing. Each group of nozzles had its own line from the main tank; therefore, spray output to specific treatment plots could be easily controlled by the sprayer operator. Sprays were applied at 100 psi at a rate of 150 gpa. Applications were made at 3- to 4-day intervals according to DBM larval egg densities observed during the prior bi-weekly insect survey. Applications were made on 6, 10, 13, 17, 20, 27, 31 Oct; 3, 7. 10, 14, 17, 24 Nov; 1 and 5 Dec for a total of 15 applications. Post-treatment evaluations were conducted on bi-weekly intervals. Ten plants were randomly selected from each treatment plot and carefully examined for immatures.

Evaluation of Emamectin Benzoate (Mk-244) and other Insecticides Against Dbm, 1995

Abstract The insecticides were evaluated at the Kula Research Station, Maui Agricultural Park, from May to June. The field was set up in a RCB design with six treatments and four replications (blocks). Each treatment plot measured 70 ft by 7.5 ft. It consisted of four rows of cabbage on 36 in. centers and 18 in. in-row spacing. Adjacent rows were offset to allow equidistant plant spacing between rows. Treatment plots in each block were separated by a 4.5 ft row spacing. Blocks were separated by a 10 ft. wide space that allowed sprayer access. Total field size was 150 ft. by 109 ft. Treatments were applied using a tractor mounted with a PTO driven spray pump equipped with a 30 ft. boom. The boom was set with three banks nozzles that coincided with row spacing. Each group of nozzles had its own line from the main tank; therefore, spray output to specific treatment plots could be easily controlled by the sprayer operator. The first treatment was applied using hollow cone TX-18 (Spraying Systems) nozzles at 100 psi. Due to excessive drift caused by the small droplet size, the nozzles were changed to TX-26 for the second to fifth treatment application. The pressure was reduced to 45 psi to give an output of 100 gallons per acre. For the last two treatments, the twin jet TJ-60 8006 nozzles at 25 psi were used for an output of 100 gallons per acre. The first treatment was made on 16 May, 12 days after transplanting. Subsequent applications were made on the following dates: 23 and 30 May, 6, 13, 20, and 27 June.

Field Evaluation of Fipronil for Dbm Control, 1996

Abstract The insecticides were evaluated at the Kula Research Station, Maui Agricultural Park, from June to August. The field was set up in a RCB design with six treatments and four replications (blocks). Each treatment plot measured 70 ft by 7.5 ft. It consisted of four rows of cabbage on 36 in. centers and 18 in. in-row spacing. Adjacent rows were offset to allow equidistant plant spacing between rows. Treatments were applied using a tractor mounted with a PTO driven spray pump equipped with a 30 ft. boom. The boom was set with three banks nozzles that coincided with row spacing. Each group of nozzles had its own line from the main tank, therefore, spray output to specific treatment plots could be easily controlled by the sprayer operator. Treatments were applied at 45 psi with an output of 125 gpa. One TJ 60-8006 nozzle was used per row. The first treatment was made on 2 Jul, 1 day after transplanting. Subsequent applications were made on the following dates: 8, 16, 23, 30 Jul, 6, 13 Aug.

Evaluation of Insecticides Against Dbm, 1995

Abstract The insecticides were evaluated at the Kula Research Station, Maui Agricultural Park, from July to September. The field was set up in a RCB design with six treatments and four replications (blocks). Each treatment plot measured 70 ft. by 7.5 ft. It consisted of four rows of cabbage on 36 in. centers and 18 in. in-row spacing. Adjacent rows were offset to allow equidistant plant spacing between rows. Treatment plots in each block were separated by a 4.5 ft. row spacing. Blocks were separated by a 10 ft. wide space that allowed sprayer access. Total field size was 150 ft. by 109 ft. Treatments were applied using a tractor mounted with a PTO driven spray pump equipped with a 30 ft. boom. The boom was set with three banks nozzles that coincided with row spacing. Each group of nozzles had its own line from the main tank, therefore, spray output to specific treatment plots could be easily controlled by the sprayer operator. The first two treatments were applied using twin jet TJ 60-8006 nozzles at 25 psi with an output of 100 gpa. Thereafter, the pressures was increased to 45 psi to give an output of 125 gpa. The first treatment was made on 18 July, 5 days after transplanting. Subsequent applications were made on the following dates: 25 July, 1,8, 15, 22, and 29 Aug.

Walking speed as a variable in knapsack sprayer operation: Perception of speed and the effect of training

Abstract Walking speed as a variable in manual spray application was investigated. Trials were conducted to evaluate people's perception of the walking speeds 0.5, 1.0 and 1.5 m s −1. The largest difference between the target speed and the speed actually walked occurred at 1.5 m s−1. although there was a large variation in actual speeds walked for each target speed. Training did not significantly improve the ability of individuals to walk at a given speed, but decreased the variation around the mean. The results are discussed in relation to the use and effect of walking speed as a parameter in manual spray application.

Effect of application volume and method on spray operator contamination by insecticide during cotton spraying

The contamination of spray operators was assessed using a fluorescent dye recovery technique with disposable polymer fabric overalls. Eight different application volumes, ranging from 0.9 to 110 l ha −1, were used with a variety of sprayer types including two types of lever-operated knapsack sprayer, a mistblower, a spinning-disc machine and an electrostatic sprayer. Total operator contamination during spray operations on a mature cotton crop was found to be dependent on the type of sprayer and application volume used: it was highest for water-based very-low-volume sprays (6–12 l ha −1) applied by mistblower and a non-motorized sprayer and lowest for conventional applications (30–110 l ha −1) with non-motorized sprayers. The distribution of contamination over an operator's protective clothing varied with the sprayer type: with non-motorized sprayers the abdomen was the most heavily affected area; contamination from electrostatic and spinning-disc machines was more evenly dispersed. It was concluded that contamination occurring during the normal application of sprays is of minimal significance when compared with contamination caused by leaking and damaged sprayers.

The flow rate of formulations through some typical hand‐held ultra low volume spinning disc atomizers

Abstract The flow rate of a formulation through hand‐held u.l.v. equipment is determined by the viscosity of the product and the diameter of the restrictor orifice fitted. A convenient flow rate onto the atomiser head is 1 ml s−1. Most hand‐held u.l.v. equipment is supplied with several interchangeable restrictors allowing the spray operator to choose one suitable for the formulation to be applied. The flow rates of four blank (containing no pesticide) u.l.v. formulations, each of different viscosity, through five different pieces of application equipment were investigated. The results are tabulated so that the spray operator can choose an appropriate restrictor to fit to the hand‐held u.l.v. equipment he wishes to use. To use this information the operator must know the viscosity of the product at the temperature he intends to spray at It should be emphasised that the results presented in no way eliminate the need for a calibration run before commencing spraying.

Control of Orchard Spraying Based on Electronic Sensing of Target Characteristics

ABSTRACT Aconventional air-carrier orchard sprayer was retrofitted with a microcomputer-based sprayer control system. A foliage volume measurement system, based on ultrasonic range trandsucers was interfaced to a computer. Three 3-nozzle manifolds on each side of the sprayer were controlled by the computer using control algorithms based on spray deposition studies. Use of the full control system resulted in spray volume savings ranging from 28 to 35% and 36 to 52% in peaches and apples, respectively. A simple intermittent control system resulted in savings from 10 to 17% in peaches and 21 to 28% in apples. In orchard comparisons between controlled vs. uncontrolled sprayer operation, spray deposition from the controlled sprayer was found to be reduced at some locations.

Optimizing the operation of a coaxial sprayer in multielement analysis with a high-frequency induction source

Optimizing the operation of a coaxial sprayer in multielement analysis with a high-frequency induction source

Photoelectrically-Operated Intermittent Sprayers for the Insecticidal Control of Horticultural Insect Pests12

Automatic intermittent sprayers, using pulse-modulated, IR sensors to detect plants and trigger insecticidal sprays, controlled insect pests of cabbage, cauliflower, and peppers during 1978–79 as well as a continuous sprayer did. Reductions in the usage of pesticides ranged from 24–51% depending upon the crop and the mode of operation of the intermittent sprayer.