Assessment of Spray Deposition and Losses in an Apple Orchard with an Unmanned Agricultural Aircraft System in China

2020 ◽  
Vol 63 (3) ◽  
pp. 619-627
Author(s):  
Yang Liu ◽  
Longlong Li ◽  
Yajia Liu ◽  
Xiongkui He ◽  
Jianli Song ◽  
...  
Keyword(s):  
Pest Control ◽  
Plant Protection ◽  
Spray Deposition ◽  
Apple Orchard ◽  
Tree Canopy ◽  
List Type ◽  
Spray Drift ◽  
Reduced Pressure ◽  
External Contamination ◽  
Aircraft System

Highlights Field tests were performed in an orchard to evaluate spray performance of an unmanned agricultural aircraft system. A conventional air-assisted orchard sprayer was applied as a reference for comparing the feasibility of UAAS. The canopy deposition, airborne drift, loss to ground, and sprayer external contamination were tested. Field test results can provide a reference for the application of UAAS for pest control in orchards. Abstract. Unmanned agricultural aircraft system (UAAS) technology has developed rapidly in China in recent years. Due to their high application efficiency, all-terrain operation, and low-volume spraying, UAASs have been widely used for pest management in field crops, achieving good pest control and reduced pressure on farmers. In this study, the applicability of UAAS for orchard protection was tested in an apple orchard by spraying with a four-rotor UAAS and a conventional air-assisted orchard sprayer. The spray characteristics of both sprayers, including canopy deposition, drift in the air, loss to the ground, and external contamination on the sprayer, were measured and compared. The field results showed that the effective spray swath width of the UAAS was 2.23 m, and the maximum droplet density was 132 droplets cm -2 in the center of the flight line. The actual deposition in the tree canopy was lower with the UAAS than with the air-assisted sprayer, but the normalized deposition of the UAAS was equivalent to that of the air-assisted sprayer, and the coefficient of variation for deposition in all parts of the canopy was obviously higher for the UAAS than for the air-assisted sprayer. Due to the airflow produced by the high-speed rotors, the spray drift in the air was much higher with the UAAS than with the air-assisted sprayer, whereas the ground loss of the UAAS was 1/5 that of the air-assisted sprayer. Moreover, the rotor airflow of the UAAS caused a large amount of droplets to attach to the sprayer fuselage, causing the external contamination on the UAAS to be five times that of the air-assisted sprayer. Results showed that the use of a multirotor UAAS for plant protection in an orchard had considerable influence on the spray drift and external contamination of the spray equipment. Based on the results, the following recommendations can be made: (1) plant protection with a UAAS should be attained by spraying at a reasonable height to reduce the drift in the air, and (2) UAAS manufacturers should develop adequate spraying systems as well as appropriate UAAS designs for plant protection. Keywords: Air-assisted orchard sprayer, Apple orchard, Spray deposition, Spray loss, UAAS.

Downwind Spray Drift Assessment for Airblast Sprayer Applications in a Modern Apple Orchard System

2021 ◽  
Vol 64 (2) ◽  
pp. 601-613
Author(s):  
Anura P. Rathnayake ◽  
Lav R. Khot ◽  
Gwen A. Hoheisel ◽  
Harold W. Thistle ◽  
Milt E. Teske ◽  
...  
Keyword(s):  
Spray Deposition ◽  
Mechanistic Model ◽  
Apple Orchard ◽  
Growth Stages ◽  
List Type ◽  
Spray Drift ◽  
Worst Case ◽  
Dormant Stage ◽  
Drift Potential ◽  
Spray Applications

HighlightsAirblast sprayer drift potential was evaluated up to 183 m (600 ft) downwind from an orchard edge.A central leader apple orchard was sprayed at dormant and full canopy stage.Higher drift at full canopy stage was likely due to higher wind speeds and lower humidity.String and artificial foliage samplers had higher collection efficiencies than Mylar cards.Abstract. Risk assessment of orchard pesticide spraying is currently based on spray drift estimation using a worst-case scenario (dormant stage). However, most spray applications are conducted during non-dormant canopy growth stages. Such overestimation leads to restrictive operational regulations in pest management activities. Therefore, field data were generated and studied for a mechanistic model that will predict spray drift from airblast spray applications in tree fruit orchards. Spray trials were conducted at dormant and full canopy growth stages in a central leader trained apple orchard. An axial-fan airblast sprayer sprayed fluorescent tracer in the third row from the orchard’s downwind edge, with four passes being one run. A total of 20 runs, i.e., 17 spray runs and three blanks, were performed during each of the two crop growth stages. Mylar cards, artificial foliage (AF), and horizontal strings (HS) were used to quantify drifting spray deposition up to 183 m (600 ft) downwind. Within the orchard, the deposition on card samplers 3 m upwind of the sprayed row was 21.94% ±4.63% (mean ± standard deviation) of applied dose (AD) at dormant stage and 16.02% ±2.86% AD at full canopy stage. Deposition downwind and adjacent (-3 m) to the sprayed row was 17.92% ±2.70% AD and 7.15% ±1.78% AD at dormant and full canopy stages, respectively. Spray drift decreased substantially at the orchard edge to 3.18% ±1.30% AD at dormant stage and 2.30% ±1.16% AD at full canopy stage. Spray drift was very low at 183 m (600 ft) downwind of the orchard, with deposition of 0.002% ±0.003% AD at dormant stage and 0.003% ±0.004% AD at full canopy stage. Deposition data collected at common sampler locations showed that HS and AF samplers collected significantly (p < 0.05) more drifting spray than card samplers. Downwind speeds had a strong linear relationship with spray drift at both growth stages (dormant: R2= 0.80, full canopy: R2= 0.86), while the influence of temperature and humidity could not be directly observed from the collected data. Keywords: Airblast spraying, Deposit samplers, Dormant and full canopy, Drift, Modern orchard systems.

Design and Experiment of an Aerial Electrostatic Spraying System for Unmanned Agricultural Aircraft Systems

2020 ◽  
Vol 36 (6) ◽  
pp. 955-962
Author(s):  
Shilin Wang ◽  
Xue Li ◽  
Hao Zhou ◽  
Xiaolan Lv ◽  
Weiguo Shen
Keyword(s):  
Droplet Size ◽  
Negative Electrode ◽  
Tree Canopy ◽  
List Type ◽  
Specific Charge ◽  
Chemical Application ◽  
Electrostatic Spraying ◽  
Aircraft Systems ◽  
Aircraft System ◽  
Pump Pressure

HighlightsA bipolar contact electrostatic spraying system is designed for an unmanned agricultural aircraft system.The electrostatic voltage does not affect the droplet size and relative span.The specific charge due to the negative electrode is higher than that due to the positive electrode.The droplets charged by the spraying system are more prone to be deposited on the underside of leaves.Abstract. Chemical application by unmanned agricultural aircraft systems (UAASs) has developed rapidly in China and other Asian countries due to their suitability to complex terrains, high working efficiency, and labor intensity reduction. To enhance spraying performance of unmanned aerial spraying systems (UASSs), an aerial electrostatic spraying system (AESS) was designed consisting of a lithium battery, electrostatic generator, positive and negative charging electrodes, tanks, pumps, and centrifugal atomizers. The AESS electrostatic voltage (EV) was adjusted from 15 to 35 kV, the atomizer rotation speed reached 9600 r/min, and the pump pressure ranged from 0.02 to 0.1 MPa. The AESS specific charge and droplet spectrum under water spraying was measured at different EVs. Results showed that the specific charge due to the negative electrostatic electrode was higher than that due to the positive electrostatic electrode. At a negative electrostatic electrode EV of 35 kV, its specific charge was 1.84 mC/kg. The negative and positive electrostatic electrode volume median diameters (VMDs) ranged from 81.39 to 84.04 µm and 86.8 to 88.80 µm, respectively, and no significant droplet size and relative span differences occurred between the different EVs for the same electrostatic electrode. The AESS was installed on single-rotor and multirotor UAASs for chemical application to pear trees. The results revealed that the electrostatic spray from the AESS has no effect on droplet deposition on the upper side of pear tree canopy leaves, while charged droplets can produce a wrap-around effect on the underside of the leaves, which promotes the adhesion of droplets on the underside of the leaves. The AESS is suitable for chemical application under aerial UAAS spraying. Keywords: Chemical application, Droplet spectrum, Deposition, Specific charge, Unmanned agricultural aircraft system.

Technical Note: Model Physics and Collection Efficiency in Estimates of Pesticide Spray Drift Model Performance

2020 ◽  
Vol 63 (6) ◽  
pp. 1939-1945
Author(s):  
Harold W. Thistle ◽  
Milton E. Teske ◽  
Brian Richardson ◽  
Tara M. Strand
Keyword(s):  
Forest Canopy ◽  
Collection Efficiency ◽  
Spray Deposition ◽  
Model Performance ◽  
Technical Note ◽  
Large Field ◽  
List Type ◽  
Spray Drift ◽  
Wind Fields ◽  
Data Limitations

HighlightsRecent large field programs are re-examined in the context of model development.Details of plant canopy wind fields are discussed.Collection efficiency of rotorods is discussed in detail, and the theory is used to re-examine field data.The approach used in the AGDISP model to simulate canopy wind fields is discussed in detail.Abstract. Recent field studies provided data to evaluate the performance of the aerial spray deposition algorithm in AGDISP. Those studies provided data for forest canopy settings that are either outside the stated domain of AGDISP or where assumptions in the model greatly impact the model performance. The two data sets were collected with the intention of providing input to drive model upgrades, but data limitations restricted that objective. Rather, this technical note shows that collection efficiency (CE) must always be considered (the model currently adjusts for CE only if the modeled output is canopy capture). One of the previous studies showed that the model substantially overpredicted droplet flux 65 m downwind of the spray line. Consideration of CE resolves some of this overprediction, but the model physics employed in AGDISP remain a substantial simplification of the complex flows that transport droplets in the atmospheric boundary layer near and in deep, three-dimensionally varying forest canopies. Keywords: Aerial application, AGDISP, Model, Spray drift.

Field Performance of a Solid Set Canopy Delivery System Configured for High-Density Tall Spindle Architecture Trained Apple Canopies

2021 ◽  
Vol 64 (6) ◽  
pp. 1735-1745
Author(s):  
Rajeev Sinha ◽  
Lav Khot ◽  
Gwen Hoheisel ◽  
Matthew Grieshop
Keyword(s):  
Delivery System ◽  
Spray Deposition ◽  
Low Cost ◽  
Vertical Plane ◽  
Apple Orchard ◽  
High Density ◽  
Growth Stages ◽  
List Type ◽  
Hollow Cone ◽  
Leaf Surfaces

HighlightsVariants of a solid set canopy delivery system were evaluated in a high-density apple orchard.A pair of hollow-cone nozzles installed in three tiers had optimum spray performance for studied crop growth stages.A shower-down arrangement of emitters was the simplest design but had lesser deposition on abaxial leaf surfaces.Abstract. Optimally configured solid set canopy delivery system (SSCDS) based spraying has potential to improve tree-fruit crop pest and disease management by reducing application time and eliminating dependence on ground conditions. In such an effort, this study attempted to optimize SSCDS variants. Four different emitter types (E1 to E4) installed in different mounting configurations (C1 to C4) were evaluated for spray deposition and coverage in a high-density apple orchard trained in tall spindle architecture. Emitters E1, E2, and E4 had full circle spray patterns, and E3 had a hollow-cone pattern. Configuration C1 had a pair of E1 emitters spraying in a vertical plane and installed between two trees at 1.5 m above ground level (AGL). Another E1 emitter spraying in a horizontal plane was mounted atop each tree at 3.3 m AGL. Configurations C2 and C4 had emitters (E2 and E4, respectively) mounted atop each tree at 3.3 m AGL, and C3 had a pair of E3 emitters installed in a three-tier arrangement between two trees in the crop row. During field trials, a tree canopy about 3.0 m tall was divided into three zones (0 to 1.4 m, >1.4 to 2.2 m, and >2.2 to 3.0 m AGL) as bottom, middle, and top canopy zones, respectively. Mylar cards were used to quantify spray deposition using fluorometry, and water-sensitive papers (WSPs) were used to quantify coverage using image processing. Configuration C3 with 80° hollow-cone nozzles in a twin-emitter, three-tier arrangement had the highest overall spray deposition (581.1 ±77.8 ng cm-2, mean ± standard error) and coverage (18.4% ±4.1%). Moreover, C3 also had a significantly higher coverage on the abaxial surfaces of leaves compared to the other configurations. Configurations C1 was non-optimal because it lacked abaxial surface coverage as the canopy grew in the middle and late growth stages. Moreover, significant spray runoff from leaf surfaces was observed visually in the middle zone for C1 during the middle and late stages. This may be attributed to canopy growth around the emitters. Configurations C2 and C4, with emitters in a shower-down arrangement, had the highest deposition and coverage in the top canopy zone compared to the middle and bottom zones. Configurations C2 and C4 also had significantly higher spray coverage on the adaxial surfaces of leaves compared to the abaxial surfaces. Overall, despite the complex design of configuration C3 with six emitters per tree, it may be the most ideal arrangement for agrochemical application in an apple orchard trained in tall spindle architecture. For commercial feasibility, we recommend exploring this three-tier SSCDS configuration with low-cost emitter alternatives. Pertinent continuing efforts have been published by our group in which we successfully modified low-cost irrigation emitters, and the resulting three-tier SSCDS configurations had improved spray performance over expensive hollow-cone nozzles. Keywords: Fixed spray system, High-density apple orchard, Solid set canopy delivery system, Spray coverage, Spray deposition, SSCDS.

Flowers for better pest control? Effects of apple orchard groundcover management on mites (Acari), leafminers (Lepidoptera, Scitellidae), and fruit pests

2012 ◽  
Vol 22 (1) ◽  
pp. 39-60 ◽  
Author(s):  
Viktor Markó ◽  
Gábor Jenser ◽  
Krisztina Mihályi ◽  
Tamás Hegyi ◽  
Klára Balázs
Keyword(s):  
Pest Control ◽  
Apple Orchard

scholarly journals Phenotyping Architecture Traits of Tree Species Using Remote Sensing Techniques

2021 ◽  
Vol 64 (5) ◽  
pp. 1611-1624
Author(s):  
Worasit Sangjan ◽  
Sindhuja Sankaran
Keyword(s):  
Remote Sensing ◽  
Structure From Motion ◽  
Tree Species ◽  
Tree Height ◽  
Tree Canopy ◽  
System Structure ◽  
List Type ◽  
Canopy Architecture ◽  
Chemical Application ◽  
Canopy Volume

HighlightsTree canopy architecture traits are associated with its productivity and management.Understanding these traits is important for both precision agriculture and phenomics applications.Remote sensing platforms (satellite, UAV, etc.) and multiple approaches (SfM, LiDAR) have been used to assess these traits.3D reconstruction of tree canopies allows the measurement of tree height, crown area, and canopy volume.Abstract. Tree canopy architecture is associated with light use efficiency and thus productivity. Given the modern training systems in orchard tree fruit systems, modification of tree architecture is becoming important for easier management of crops (e.g., pruning, thinning, chemical application, harvesting, etc.) while maintaining fruit quality and quantity. Similarly, in forest environments, architecture can influence the competitiveness and balance between tree species in the ecosystem. This article reviews the literature related to sensing approaches used for assessing architecture traits and the factors that influence such evaluation processes. Digital imagery integrated with structure from motion analysis and both terrestrial and aerial light detection and ranging (LiDAR) systems have been commonly used. In addition, satellite imagery and other techniques have been explored. Some of the major findings and some critical considerations for such measurement methods are summarized here. Keywords: Canopy volume, LiDAR system, Structure from motion, Tree height, UAV.

scholarly journals Tank mixtures of pesticides for plant protection

2019 ◽  
Vol 5 (3) ◽  
pp. 163-167
Author(s):  
M. Makarov
Keyword(s):  
Pest Control ◽  
Plant Protection ◽  
Chemical Plant ◽  
Systemic Fungicides ◽  
Toxicological Effects ◽  
Interaction Of Components ◽  
Active Substances

Today, chemical plant protection methods are based on the safe use of pesticides. Environmental and toxicological effects are taken into account. To expand the possibilities of pest control, diseases and weeds, in the cultivation of crops, use tank mixtures that contain two or three active substances. In the preparation of mixtures take into account the processes of interaction of components and timing of application of drugs. In addition, this technique is one of the elements of the strategy to overcome the resistance of pests to insecticides, pathogens — to systemic fungicides, weeds — to herbicides.

scholarly journals Silencing cathepsin L expression reduces Myzus persicae protein content and the nutritional value as prey for Coccinella septempunctata

2018 ◽  
Author(s):  
Imran Rauf ◽  
Muhammad Asif ◽  
Imran Amin ◽  
Rubab Zahra Naqvi ◽  
Noroza Umer ◽  
...  
Keyword(s):  
Rna Interference ◽  
Transgenic Plants ◽  
Protein Content ◽  
Pest Control ◽  
Myzus Persicae ◽  
Nutritive Value ◽  
Cathepsin L ◽  
Coccinella Septempunctata ◽  
List Type ◽  
Rnai Construct

AbstractGut-expressed aphid genes, which may be more easily inhibited by RNA interference (RNAi) constructs, are attractive targets for pest control efforts involving transgenic plants. Here we show that expression of cathepsin L, a cysteine protease that functions in aphid guts, can be reduced by expression of an RNAi construct in transgenic tobacco. The effectiveness of this approach is demonstrated by up to 80% adult mortality, reduced fecundity, and delayed nymph production of Myzus persicae (green peach aphids) when cathepsin L expression was reduced by plant-mediated RNAi. Consistent with the function of cathepsin L as a gut protease, M. persicae fed on the RNAi plants had a lower protein content in their bodies and excreted more protein in their honeydew. Larvae of Coccinella septempunctata (seven-spotted ladybugs) grew more slowly on aphids having reduced cathepsin L expression, suggesting that prey insect nutritive value, and not just direct negative effects of the RNAi construct, needs to be considered when producing transgenic plants for RNAi-mediated pest control.HighlightsSilencing expression of cathepsin L by RNA interference reduces protein content of Myzus persicae (green peach aphid) bodies.Honeydew of aphids with cathepsin L silenced contains elevated protein.Cathepsin L is required for efficient protein uptake from phloem sap.Aphids with cathepsin L expression silenced have increased mortality and fewer offspring.Coccinella septempunctata (seven-spotted ladybugs) grow more slowly on aphids with expression of cathepsin L silenced.

scholarly journals Development of methods for application of pheromonic materials for monitoring and managing the number of apple phytophages

2021 ◽  
pp. 47-53
Author(s):  
I. S. Agasieva ◽  
V. Ya. Ismailov ◽  
A. S. Nastasiy ◽  
M. V. Nefedova
Keyword(s):  
Species Composition ◽  
Sex Pheromones ◽  
Apple Tree ◽  
Plant Protection ◽  
Central Zone ◽  
Apple Orchard ◽  
Species Specificity ◽  
Insect Sex Pheromones ◽  
Natural Dynamics ◽  
And Control

Synthetic sex pheromones have found wide application in plant protection as a mean of early detection of pests that allows observation of the phenology of insects to optimise protective measures. Insect sex pheromones can be applied for different purposes in protecting crops such as monitoring, determining the species composition and combating harmful species (by using sex pheromones for disorientation). The present work studies the species composition, dynamics of the number of basic pests of an apple tree, synchronisation of the seasonal and circadian activity of phytophages of an apple tree in the central zone of the Krasnodar Territory. The results of the field assessment of the male complex disorientation method of apple and eastern moths are presented. It was shown that the species-specificity of sex pheromones in the apple orchard depends on the faunistic diversity of Lepidoptera species with similar pheromone systems that develop at a given point in space and time. It was revealed that the behaviour of this complex changes during the season and over years, depending on the climate and natural dynamics of insect populations. The quantitative ratio and species-specificity of pheromones will probably be different in ecosystems with various species composition and different geographic zones. A novelty of this research is the division of the studied Lepidoptera phytophage species into three groups according to a decrease in the absolute species-specificity in the forest biotope in comparison with the garden one. The most widespread and coinciding in terms of summer synchronicity are apple (Cydia pomonella L.), plum (Grapholitha funebrana Tr.), eastern (Grapholitha molesta Tr.) and pomegranate moth (Euzophera bigella Zell.). The disorientation method, applied using a complex system of dispensers with apple and eastern moth pheromones, showed that installing 500 dispensers/ha allowed 99.3 % efficiency to be achieved. Fruit damage amounted to 1.2 % and 2.7 % in the experimental and control groups, respectively. The duration of the disorienting effect of the pheromone formulations lasted for over 4 months.

Spray Recovery From Nozzles Designed to Reduce Drift

Weed Science ◽  
1976 ◽  
Vol 24 (4) ◽  
pp. 361-365 ◽  
Author(s):  
L. F. Bouse ◽  
J. B. Carlton ◽  
M. G. Merkle
Keyword(s):  
Low Pressure ◽  
Spray Drift ◽  
Hollow Cone ◽  
Reduced Pressure ◽  
Release Point

Low pressure and reduced pressure fan and reduced pressure hollow cone nozzles were compared to conventional fan and hollow cone nozzles to determine their potential for reducing spray drift. Other comparisons included two different spray pressures for a low pressure fan nozzle, low and reduced pressure fan nozzles versus air-aspirating foam nozzles, low pressure versus reduced pressure fan nozzles, and reduced pressure hollow cone nozzles versus reduced pressure fan nozzles. Spray recoveries within 36 m downwind of the spray release point were significantly greater for the low pressure and reduced pressure fan and reduced pressure hollow cone nozzles than for the conventional fan and hollow cone nozzles. An air-aspirating nozzle producing spray without foaming adjuvant resulted in significantly greater spray recovery than a low pressure fan nozzle. The recovery from a reduced pressure fan nozzle having a rated flow of 12.6 cm3/s was significantly greater than that from a low pressure fan nozzle.

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