Spray Boom Research Articles

Autonomous systems for precise spraying – Evaluation of a robotised patch sprayer

Advances in different technologies, such as global navigation satellite systems, geographic information systems, high-resolution vision systems, innovative sensors and embedded computing systems, are finding direct application in agriculture. These advances allow researchers and engineers to automate and robotise agricultural tasks no matter the inherent difficulties of the natural, semi-structured environment in which these tasks are performed. Following this current trend, this article aims to describe the development and assessment of a robotised patch spraty -20ying system that was devised for site-specific herbicide application in agricultural crops and is capable of working in groups or fleets of autonomous robots. The robotised patch sprayer consisted of an autonomous mobile robot based on a commercial agricultural vehicle chassis and a direct-injection spraying boom that was tailor-made to interact with the mobile robot. There were diverse sources (on-board and remote sensors) that can supply the weed data for the treatment. The main features of both the mobile robot and the sprayer are presented along with the controller that harmonised the behaviour of both main subsystems. Laboratory characterisation and field tests demonstrated that the system was reliable and accurate enough to accomplish the treatment over 99.5% of the detected weeds and treatment of the crop with no weed treated was insignificant; approximately 0.5% with respect to the total weed patches area, achieving a significant herbicide savings.

Efficacy of entomopathogenic nematodes against larvae of Tuta absoluta in the laboratory.

Previous studies have indicated the control potential of entomopathogenic nematodes (EPNs) against Tuta absoluta. Here, the potential of Steinernema feltiae, S. carpocapsae and Heterorhabditis bacteriophora is studied when applied against larvae of T. absoluta inside leaf mines in tomato leaf discs by means of an automated spray boom. The studied EPN species were effective against all four larval instars of T. absoluta but caused higher mortality in the later instars (e.g. fourth instar: 77.1-97.4% mortality) than in the first instars (36.8-60.0% mortality). Overall, S. feltiae and S. carpocapsae yielded better results than H. bacteriophora. Steinernema carpocapsae and H. bacteriophora performed better at 25 °C (causing 55.3 and 97.4% mortality respectively) than at 18 °C (causing 12.5 and 34.2% mortality respectively), whereas S. feltiae caused 100% mortality at both temperatures. Under optimal spraying conditions and with the use of Addit and Silwet L-77 adjuvants, a reduced dosage of 6.8 infective juveniles (IJs) cm(-2) yielded equally good control as a recommended dosage of 27.3 IJs cm(-2) . Under laboratory conditions, S. feltiae and S. carpocapsae showed good potential against the larvae of T. absoluta inside tomato leaf mines. Results need to be confirmed in greenhouse experiments. © 2015 Society of Chemical Industry.

Curative Control of the Peachtree Borer Using Entomopathogenic Nematodes.

The peachtree borer, Synanthedon exitiosa (Say 1823), is a major pest of stone fruit trees in North America. Current management relies upon preventative control using broad-spectrum chemical insecticides, primarily chlorpyrifos, applied in the late summer or early fall. However, due to missed applications, poor application timing, or other factors, high levels of S. exitiosa infestation may still occur and persist through the following spring. Curative treatments applied in the spring to established infestations would limit damage to the tree and prevent the next generation of S. exitiosa from emerging within the orchard. However, such curative measures for control of S. exitiosa do not exist. Our objective was to measure the efficacy of the entomopathogenic nematode, Steinernema carpocapsae, as a curative control for existing infestations of S. exitiosa. In peach orchards, spring applications of S. carpocapsae (obtained from a commercial source) were made to infested trees and compared with chlorpyrifos and a water-only control in 2014 and 2015. Additionally, types of spray equipment were compared: nematodes were applied via boom sprayer, handgun, or trunk sprayer. To control for effects of application method or nematode source, in vivo laboratory-grown S. carpocapsae, applied using a watering can, was also included. Treatment effects were assessed 39 d (2014) or 19 d (2015) later by measuring percentage of trees still infested, and also number of surviving S. exitiosa larvae per tree. Results indicated that S. carpocapsae provided significant curative control (e.g., >80% corrected control for the handgun application). In contrast, chlorpyrifos failed to reduce S. exitiosa infestations or number of surviving larvae. In most comparisons, no effect of nematode application method was detected; in one assessment, only the handgun and watering can methods reduced infestation. In conclusion, our study indicates that S. carpocapsae may be used as an effective curative measure for S. exitiosa infestations.

Droplets spectrum of air-assisted boom sprayers under different environmental and operational conditions

ABSTRACT During pesticide spraying, the psychrometric conditions of the air may cause evaporation of the droplets along their trajectory from the nozzle to the target. Thus, this study aimed to evaluate the effect of air psychrometric conditions and operating pressure on the droplet spectrum of air-assisted boom sprayers. The test was performed using a prototype equipped with an axial fan, a flow homogenizer, temperature and relative air humidity sensors, a spray nozzle and a gas-heating system to warm up the airflow. With the assembled system and the aid of a particle analyser, the JSF 11002 spray nozzle was evaluated with respect to droplet spectrum in four air psychrometric conditions (7, 14, 21 and 28 hPa) and at four operating pressures (200, 300, 400 and 500 kPa). At the end, evaporation losses were observed during the sprayings. For a given operating pressure and for each increment of 1 hPa in vapor pressure deficit, there was a diameter reduction of approximately 0.0759, 0.518 and 1.514 μm for the parameters DV0.1, DV0.5 and DV0.9, respectively. The diameter of the droplets decreased as the operating pressure increased.

Blueberry Tip Midge Control, 2015: Table 1

This experiment was conducted on lowbush blueberry to evaluate the effectiveness of five insecticides against blueberry tip midge (TM). Materials were applied to 7 × 20-ft plots in a vegetative-year blueberry field at Jonesboro, ME. There were four treated plots for each material plus four untreated check plots. All treatments were applied in 25 gal of water-mixture per acre using a CO2-propelled, 80-inch boom sprayer (76-inch swath), with four, flat spray 8002VS TeeJet …

回転型アクティブ除振装置AWDによるスカイフック－外乱相殺併合制御と動的量子化器を用いた低分解能制御系の除振性能

This study develops a Active Wheel Damper Device (AWD) that can be attached easily to the boom sprayer. The AWD achieves lightweight and higher inertia by the flywheel and can be mounted on the flexible structure easily. In addition, this AWD can construct realize sky-hook control easily because of it can measure the absolute angular velocity of the flexible structure by the gyro sensor. Therefore, the AWD uses Sky-hook with Disturbance Cancellation (SWDC) control that combined control system of sky-hook control and disturbance cancellation control. Damping performance of AWD has been confirmed by presented studies, but for practical use of AWD, reduction of production cost of AWD is more necessary. Then, we suppose deterioration of resolution due to using the low cost and low resolution controller. In addition, we examine whether the performance of AWD can be kept when adding the dynamic quantizer. In the previous study, we have shown the influence of torque of motor on control performance, but not yet carried out a study on the effect of the sampling period. In this paper, we clarify the relationship between the sampling period of the controller and the maximum torque of the motor by introducing angular-momentum resolution.

Insecticide Efficacy in Alfalfa Seed Production, 2013

The objective of the study was to evaluate new insecticides for their efficacy against adults and nymphs of WTPB and other insect pests on alfalfa grown for seed production under desert conditions. An insecticide efficacy trial was conducted at the UC Desert Research and Extension Center, Holtville, CA on a stand of CUF-101 alfalfa on beds of 40-inch centers; the stand was sprayed with Dibrom 8 @ 1.5 pt/acre on 20 May 2013 to control pests prior to initiating seed production. The experimental design was RCB using four replicates with 11 insecticide treatments and an untreated check. Plots were eight beds 40 ft wide by 70 ft long, with 5 ft buffers between replicate blocks. The insecticide treatments were applied on the dates at the specified rate equivalencies listed in Table 1. The insecticide treatments were broadcast sprays applied with a Lee Spider Spray Trac, tractor mounted spray boom, equipped with 15 nozzles (TJ-60 11003VS), operated at 30 psi and delivering 36 gpa in a 20-ft wide spray swath. Hasten, a modified vegetable oil surfactant (Wilber-Ellis Company), was applied at 0.25% vol/vol in tank mixtures with each insecticide treatment. The pretreatment (PT) insect population …

Cross-spectrum Insect Control with Foliar Insecticides in Broccoli, 2014: Table 1

The objective of this trial was to evaluate the efficacy of insecticide mixtures compared to Exirel applied alone, for cross-spectrum control of major insect pests (sucking and chewing pests) in broccoli under fall growing conditions. Broccoli “Emerald Crown” was direct seeded into double row beds on 42-inch centers on 4 September, 2014. Plots were two beds in width by 45 ft in length and bordered by two untreated beds. Stand establishment was achieved using overhead sprinkler irrigation and irrigated with furrow irrigation thereafter. Four replications of each treatment were arranged in an RCB design. Product formulations and rates for each compound are provided in Table 1. Two foliar sprays were applied on 30 September and 15 October with a CO2 pressurized boom sprayer that delivered a broadcast application through 2 TXVS-18 …

Blueberry Tip Midge Control, 2014: Table 1

This experiment was conducted on lowbush blueberry to evaluate the effectiveness of five insecticides against blueberry tip midge (TM). Materials were applied to 7- by 20-ft plots in a vegetative-year blueberry field at Jonesboro, ME. There were four treated plots for each material plus four untreated check plots. All treatments were applied in 25 gpa using a CO2-propelled, 80-inch boom sprayer (76-inch swath), with four, flat spray 8002VS TeeJet nozzles operating at 35 psi. Rimon 0.83EC (novaluron), Success …

Influence of air-assistance on spray application for tomato plants in greenhouses

Protected horticulture production represents one of the most important agricultural businesses in Southern Europe. However, many problems related to the lack of mechanisation, intensive use of pesticides, and, in some cases, undesirable residues on food, have not been solved yet. In this context, application technology is a key factor for the improvement of the efficacy and efficiency of plant protection products. Spray guns and knapsack sprayers are the most common technologies that have been used for this purpose. However, several studies have demonstrated that, compared with spray guns, the use of vertical boom sprayers in greenhouses improves spray distribution and reduces labour costs and operator exposure. The main objective of this study was to evaluate the influence of air-assistance on spray application in conventional tomato greenhouses. For this purpose three different spray conceptions were evaluated: 1) a modified commercial handheld trolley sprayer with two air assistance concepts; 2) a self-propelled sprayer; and 3) an autonomous self-propelled sprayer with remote control. All the sprayers considered were evaluated in terms of absolute and normalised canopy deposition, uniformity of distribution, and losses to the ground. In addition, the vertical liquid and air velocity distributions of the sprayers were assessed and compared with the canopy profiles and spray depositions. Yellow tartrazine (E-102 yellow) was used as a tracer for deposition evaluation. The results indicated that increasing the air velocity does not increase the efficiency of a spray application. In general, the modified handheld trolley sprayer showed the best results in terms of deposition and uniformity of distribution, especially at the lowest air assistance rate. These results were confirmed with evaluation of the uniformity of the air and liquid distribution.

APPLICATION HEIGHT IN HERBICIDES EFFICIENCY IN BEAN CROPS

ABSTRACTInadequate herbicide application can result in failures in weed control and/or poisoning of the crops, resulting in yield losses. In this research were assessed the effects of the sprayer nozzle boom height in the distribution of the spray solution for weed control, influencing intoxication of beans and crop yield. Experiments were conducted in laboratory and field conditions. In laboratory, the performance of flat spray tip TT 11002 was assessed at heights 0.20, 0.30, 0.40 and 0.50 meters with respect to the target surface. In the field the same heights were assessed in applications of herbicides fomesafen, fluazifop-P-butyl and fomesafen + fluazifop-P-butyl. There was an inverse relationship between the height of the spray boom and the coefficients of variation of the patterns. The mixture better efficiency in a tank of fluazifop-P-butyl + fomesafen was obtained with the height of 0.50 m from the target. This treatment resulted in better weed control, lower poisoning of the bean plants and better crop yield rates.

Modellierung, Simulation und Optimierung des horizontalen Bewegungsverhaltens eines landwirtschaftlichen Spritzgestänges

The study reported here presents a method offering realistic depiction of horizontal motion behaviour of agricultural sprayer booms and for reducing the extent of the simulation model involved. Additionally, various solutions of reducing boom vibrations are presented and compared with the help of simulation. Thereby is demonstrated the extent to which boom motion behaviour on booms with large working widths can be improved through passive vibration absorbers and an active vibration isolation.

Distribution pattern, surface tension and contact angle of herbicides associated to adjuvants on spraying and control of Ipomoea hederifolia under rainfall incidence

ABSTRACT Scarlet Morning Glory is considered to be an infesting weed that affects several crops and causes serious damage. The application of chemical herbicides, which is the primary control method, requires a broad knowledge of the various characteristics of the solution and application technology for a more efficient phytosanitary treatment. Therefore this study aimed to characterize the effect of rainfall incidence on the control of Ipomoea hederifolia, considering droplet size, surface tension, contact angle of droplets formed by herbicides liquid on vegetal and artificial surfaces, associated to adjuvants and the volumetric distribution profile of the spray jet. The addition of the adjuvants to the herbicide spraying liquid improved the application quality, as it influenced the angle formed by the spray by broadening the deposition band of the spray nozzle and thus the possible distance between the nozzles on spray boom and due the changes at droplet size, which contribute to a safety application. The rainfall occurrence affected negatively the weed control with the different spraying liquids and also the dry matter weight, suggesting that the phytosanitary product applied was washed off.

Chemical ripening of sugarcane with trinexapac-ethyl (Moddus®) — Mode of action and comparative efficacy

Chemical ripeners cause growth suppression, thus increasing sucrose accumulation in sugarcane by lowering the growth sink demand for sucrose. Trinexapac-ethyl (Moddus®), the most recent chemical to be introduced as a ripener with a hormonal mechanism, inhibits production of the plant hormone gibberellic acid, which leads to restriction of internode elongation. This study reports novel findings on a dual mode of action, by which Moddus® affects growth processes in both the stalk and leaf canopy above a certain concentration, and how this influences ripening efficacy. In addition the efficacy of Moddus® is compared to Ethephon®, the other ripener with a hormonal mechanism. An irrigated field trial was planted to variety N32 at the South African Sugarcane Research Institute’s research station in Pongola, South Africa. The plant and subsequent three ratoons were used as experimental crops and harvested in April of each year. Replicated treatment plots consisted of 6 cane rows, 16m long and spaced 1.4m apart. Treatments comprised an unsprayed control, Ethephon® applied according to standard practise, and Moddus® applied at three dosages. Products were applied with CO2-pressurised equipment and a hand-held overhead spray boom. Measurements on the stalks (length, individual internode elongation and juice quality) and leaves (green and dead leaf mass per stalk) were conducted at intervals until harvest. At harvest the cane and sugar yield was determined for each treatment. A novel finding was that Moddus®, above a certain concentration, ripened the crop through a dual mode of action involving restriction of both internode elongation and leaf growth. Characterisation of effects on individual internode elongation and mass of the green leaf canopy, coupled to yield data, provided insights to be considered in future when attempting to explain varietal differences in response to Moddus®. The easy-to-measure plant processes identified in this study as sensitive indicators of ripening efficacy might enable initial pot-based screening of large numbers of varieties for responsiveness to Moddus®, before embarking on more time-consuming and expensive field-based testing. The data acquired in this study could also be used in attempts to simulate Moddus®-induced ripening with mechanistic sugarcane crop models.

Pneumatic delivery and deposition of drops of working fluid on plants to protect them from pests, diseases and weeds

The article presents the results of researches on the pneumatic delivery of working fluid drops to plants with the maximum deposition and fixing of appropriately sized drops on stalks and leaves with the use of additional air stream. To solve the problem of sweeping out and deposition of fine aerosol on plants, it is proposed to use in boom sprayer a pneumatic device with slotted nozzles.

Hygienic estimation of occupational risk and substantiation of regulations on Orvego Fungicide safe application in agricultural sector.

Hygienic evaluation of labour conditions during Orvego pesticide application on grapes and onion was carried out and content of ametoctradin and dimethomorp in the working zone air, atmospheric air, and the soil was studied. The findings allow to substantiate ametoctradin hygienic standards in the working zone air, atmospheric air, and the soil and to elaborate regulations of Orvego pesticide safe application in agriculture. Estimation of complex risk of ametoctradin and dimethomorp effects via different routes of exposure during airblast and boom spraying treatment showed that the values of the risks were within the ranges of allowable (<1). Values of combined risk during simultaneous effect of the both active ingredients do not exceed allowable level (<1) either.

Comparative performance of tractor operated boom type field sprayers on cotton crop

Boom sprayers are the hydraulic equipment in which sprayers move the liquid to the individual nozzles along the boom and generally used for application of pesticides on field crops such as cotton, soybean etc. Two 12 meter tractor operated boom type field sprayers of the ASPEE make one of the existing design and other of new design (developed) having similar specifications were selected for the study. The necessary set up was built up in the laboratory and said sprayers were evaluated for their performance for the parameters such as liquid distribution, flow rate of the pump, pressure and discharge of nozzles and droplet deposition on the leaves of cotton plant. Comparative performance showed that the liquid distribution under the developed boom sprayer improved, the mean discharge and pressure of developed boom sprayer increased by 49 per cent and 184.4 per cent, respectively. The discharge and pressure of the developed boom sprayer was nearly uniform in all nozzles, droplet size (VMD), droplet density (DD) and uniformity co-efficient (UC) for the existing sprayer ranged from 130.9 to 206.39 ?m, 11 to 27 drops/cm 2 and 1.18 to 1.31, whereas for developed sprayer it was ranged from 155.44 to 181.55 ?m, 17 to 29 drops/ cm 2 and 0.99 to 1.23, respectively.

Air Assisted Sprayer for Improved Spray Penetration in Greenhouse Floriculture Crops

Air assisted spraying is considered as one of the better pesticide application technique. Incorporation of air assistance in the spraying system improves the deposition uniformity in the entire plant canopy structure and spray deposition on the lower part of the plant leaves. In the view of this, an air assisted sleeve boom sprayer was developed for greenhouse floricultural crops. The developed sprayer consisted of air delivery system and spray delivery system. Air delivery system consisted of blower, lance assembly and a tapered air sleeve. Spray delivery system consisted of a pesticide tank, horizontal triplex pump, pressure hose and nozzles. Blower and pump were operated by 5 HP electric motor. Air sleeve and nozzles were supported on horizontal boom. The whole assembly of the sprayer was mounted on the trolley. The developed sprayer was tested in the laboratory to study the effect of different air velocity (9, 12, 16 and 20 m/s) and pump discharge (2.5, 4.5, 7 and 9 L/min) levels on droplet size (VMD), droplet density and uniformity coefficient at six different positions of the artificial plant canopy. Test results revealed that an increase in air velocity resulted in better spray penetration and uniform spray coverage. The optimum results of droplet size (100–150 µm), droplet density (25–35 droplets per cm2) and uniformity coefficient at all plant positions were observed for air velocity of 20 m/s and pump discharge of 2.5 L/min.

Field Evaluation of Air Assisted Sleeve Boom Sprayer

Effective pest control can be achieved, if pesticides are properly applied at correct rate, at right time and on the target by appropriate equipment. The spray with conventional sprayer does not reach the bottom of the plant canopy and also the upper and lower side of leaves in required quantity. In view of this a new air sleeve boom sprayer was designed, developed and its performance was evaluated in the laboratory and field trials. The working principle of the sprayer was totally based on the replacement of air within the canopy with spray laden air. A laboratory set up was developed and tested on actual plant canopy of cotton crop at four experimental variables viz, air velocity (12, 20 and 26 m/s), air sleeve angle (-150 , 00 , 150 and 300 ), nozzle angle (250 , 350 and 450 ) and height of boom (50 cm and 70 cm). In the study, special emphasis was given to determine the effective droplet density and droplet size for the control of pests. The deposition of droplet was made at top, middle and bottom position of the plant and on upper and lower leaf surfaces. The results indicated that the recommended levels of droplet density and size were obtained at an air velocity of 26 m/s, air sleeve angle 300 , nozzle angle 350 and height of boom 70 cm during lab experiment. The deposition indices during field trials were also calculated at these selected levels of variables. The value of regression coefficient was calculated in laboratory experiments to determine the effect of air velocity, air sleeve angle, nozzle angle and height of boom and to confirm field experiments.

Influence of wind velocity and wind direction on measurements of spray drift potential of boom sprayers using drift test bench

In 2009, the European Directive for a Sustainable Use of Pesticides (128/2009/CE) established important mandatory actions to be accomplished by all Member States (MS) in the European Union. The main objective is to achieve the sustainable use of pesticides by reducing their risks and impacts on human health and the environment. Among other important actions, drift reduction measures are essential to avoid the entry of plant protection products (PPP) in water or other undesirable areas. As the risk of environmental contamination is directly related to the spray application technology, there is a strong need for objective methods for drift evaluation as well as robust procedures for the classification of sprayers according to their risk of contamination. For this purpose, and as a complementary tool to actual drift measurement methodologies in the field or in laboratory conditions, a new method has been proposed for the quantification of the potential drift generated by horizontal boom sprayer systems using an ad hoc test bench.This study aims to evaluate the influence of wind velocity and wind direction on the drift potential value (DPV) using the proposed methodology and test bench. The results indicated that wind velocities below 1.0ms−1 have a negligible influence on the DPV. Front wind led to higher DPVs than lateral wind. A global analysis of data indicates that the proposed methodology and test bench are interesting tools for the quick and objective evaluation of the potential drift if used in appropriate environmental conditions.