Method for Estimating Canopy Thickness Using Ultrasonic Sensor Technology

The accurate detection of canopy characteristics is the basis of precise variable spraying. Canopy characteristics such as canopy density, thickness and volume are needed to vary the pesticide application rate and adjust the spray flow rate and air supply volume. Canopy thickness is an important canopy dimension for the calculation of tree canopy volume in pesticide variable spraying. With regard to the phenomenon of ultrasonic waves with multiple reflections and the further analysis of echo signals, we found that there is a proportional relationship between the canopy thickness and echo interval time. In this paper, we propose a method to calculate canopy thickness using echo signals that come from ultrasonic sensors. To investigate the application of this method, we conducted a set of lab-based experiments with a simulated canopy. The results show that we can accurately estimate canopy thickness when the detection distance, canopy density, and canopy thickness range between 0.5and 1.5 m, 1.2 and 1.4, and 0.3and 0.6 m, respectively. The relative error between the estimated value and actual value of the simulated canopy thickness is no higher than 8.8%. To compare our lab results with trees in the field, we measured canopy thickness from three naturally occurring Osmanthus trees (Osmanthus fragrans Lour). The results showed that the mean relative errors of three Osmanthus trees are 19.2%, 19.4% and 18.8%, respectively. These results can be used to improve measurements for agricultural production that includes both orchards and facilities by providing a reference point for the precise application of variable spraying.

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Measuring crop canopy – the development of a dynamic system for precision fruit crop spraying

Advances in Animal Biosciences ◽

10.1017/s2040470017000905 ◽

2017 ◽

Vol 8 (2) ◽

pp. 250-254 ◽

Cited By ~ 2

Author(s):

T. Palleja Cabre ◽

J. Llorens ◽

A. J. Landers

Keyword(s):

Current Practice ◽

Application Rate ◽

Training System ◽

Liquid Volume ◽

Canopy Density ◽

Canopy Volume ◽

System Input ◽

Time Changes ◽

Development And Validation ◽

Optimum Application

The precise application of pesticides to fruit crops requires information regarding the tree or vine canopy as a system input in order to control the amount of liquid and air being applied. Variations in canopy volume and density occur due to variety, trellis system, growth stage, training system and season. Current practice is to occasionally change liquid volume but seldom to change airflow. This paper details the development and validation of an ultrasonic sensor system to measure not only canopy volume but also canopy density and presence. Sensors fitted to the sprayer can record, in real time, changes in crop characteristics as the sprayer moves along the row. Signals can then send information to variable output nozzles and adjustable air fans. Trials have been conducted and results have proven to be extremely reliable and accurate. The ability to precisely control the spray results in the optimum application rate, leading to better results in the use of pesticides, less environmental pollution (less drift and less leaf runoff) and improved economic viability for the fruit grower.

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Spray Volume, Canopy Density, and Other Factors Involved in Thinner Efficacy

HortScience ◽

10.21273/hortsci.33.3.553d ◽

1998 ◽

Vol 33 (3) ◽

pp. 553d-553

Author(s):

C.R. Unrath

Keyword(s):

Tree Height ◽

Tree Canopy ◽

Tree Size ◽

Water Volume ◽

Canopy Density ◽

The North ◽

Run Off ◽

Tree Canopies ◽

Average Water ◽

Water Volumes

Historically, most airblast chemical applications to apple orchards used a single “average” water volume, resulting in variability of coverage with tree size and also the greatest variable in chemical thinning. This coverage variability can be eliminated by properly quantifying the tree canopy, as tree row volume (TRV), and relating that volume to airblast water rate for adequate coverge. Maximum typical tree height, cross-row limb spread, and between-row spacing are used to quantify the TRV. Further refinement is achieved by adjusting the water volume for tree canopy density. The North Carolina TRV model allows a density adjustment from 0.7 gal/1000 ft3 of TRV for young, very open tree canopies to 1.0 gal/1000 ft3 of TRV for large, thick tree canopies to deliver a full dilute application for maximum water application (to the point of run-off). Most dilute pesticide applications use 70% of full dilute to approach the point of drip (pesticide dilute) to not waste chemicals and reduce non-target environmental exposure. From the “chemical load” (i.e., lb/acre) calculated for the pesticide dilute application, the proper chemical load for lower (concentrate) water volumes can be accurately determined. Another significant source of variability is thinner application response is spray distribution to various areas of the tree. This variability is related to tree configuration, light, levels, fruit set, and natural thinning vs. the need for chemical thinning. Required water delivery patterns are a function of tree size, form, spacing, and density, as well as sprayer design (no. of nozzles and fan size). The TRV model, density adjustments, and nozzle patterns to effectively hit the target for uniform crop load will be addressed.

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Structure and Regeneration of Sal (Shorea robusta Gaertn. f.) Forests in Shiwalik Region of Kumaun Himalaya, India

Indian Journal of Forestry ◽

10.54207/bsmps1000-2017-0n83l0 ◽

2017 ◽

Vol 40 (1) ◽

pp. 1-8

Author(s):

Bhawna Adhikari ◽

◽

Bhawana Kapkoti ◽

Neelu Lodhiyal ◽

L.S. Lodhiyal ◽

...

Keyword(s):

Tree Species ◽

Basal Area ◽

Tree Canopy ◽

Canopy Density ◽

Kumaun Himalaya ◽

Shorea Robusta ◽

Canopy Trees ◽

Dense Forest ◽

Open Forest ◽

Sal Forest

Present study was carried out to assess the structure and regeneration of Sal forests in Shiwalik region of Kumaun Himalaya. Vegetation analysis and tree canopy density was determined by using quadrat and densitometer, respectively. Density of seedlings, saplings and trees was 490-14067, 37-1233, and 273-863 ind.ha-1 respectively. The basal area was 0.12-5.44 m2 ha-1 reported for saplings and 25.4-77.6 m2 ha-1 for trees. Regeneration of Sal was found good in Sal mixed dense forest followed by Sal open forest and Sal dense forest, respectively. Regeneration of Sal was assisted by the presence of associated tree species as well as the sufficient sunlight availability on ground due to adequate opening of canopy trees in Sal forest. Thus it is concluded that the density of tree canopy, sunlight availability and also associated tree species impacted the regeneration of Sal in the region.

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Phenotyping Architecture Traits of Tree Species Using Remote Sensing Techniques

Transactions of the ASABE ◽

10.13031/trans.14419 ◽

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.

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Growth and yield of clonal guavas in south-eastern Queensland

Australian Journal of Experimental Agriculture ◽

10.1071/ea9860619 ◽

1986 ◽

Vol 26 (5) ◽

pp. 619

Author(s):

KR Chapman ◽

B Paxton ◽

DH Maggs

Keyword(s):

Fruit Size ◽

Tree Height ◽

Tree Canopy ◽

Tree Size ◽

Growth And Yield ◽

Marketable Yield ◽

Cross Sectional ◽

South Eastern ◽

Canopy Volume ◽

Highly Correlated

Five processing guava clones (GA6- 1, GA7- 12, GA8-30, GA9-35, GA11-56) were tested over 3 cropping years at Nambour, in coastal south-eastern Queensland. Mean marketable yield for the first crop at 2 years of age was 45 kg/tree or 36.23 t/ha at a density of 805 trees/ha. GA11-56, the most acceptable clone for processing, also gave the highest marketable yields of 627, 71.65 and 72.53 t/ha for the first 3 crops. Yield per unit cross sectional area of trunk was a more simple and useful index of yield efficiency than more complex parameters including a fruitfulness index and multiple regressions with yield of north-south canopy spread, number of primary branches and combinations of these and trunk girth. Similarly, trunk - - girth provided at least as good an estimate of tree size as the vigour index. Tree dimension measurements which included east-west canopy spread, north-south canopy spread, tree height, stem height, number of primary branches, crown height, crown radius, tree canopy volume, canopy surface area and an index of crown weight provided no consistent indication of tree size. They were not highly correlated with either accumulated or final yield of the guava. The GA11-56 clone because of its yield, fruit size and other desirable processing characteristics was the only clone that could be recommended for commercial plantings.

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Laser, ultrasonic and manual measurements of citrus tree canopy volume

10.13031/2013.3431 ◽

2001 ◽

Author(s):

S. D. Tumbo ◽

M. Salyani ◽

J. D. Whitney ◽

T. A. Wheaton ◽

W. M. Miller

Keyword(s):

Tree Canopy ◽

Citrus Tree ◽

Laser Ultrasonic ◽

Canopy Volume

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Indicator Crop Bioassays to Define Citrus Productivity in Sandy Soils

HortScience ◽

10.21273/hortsci.45.12.1859 ◽

2010 ◽

Vol 45 (12) ◽

pp. 1859-1865 ◽

Cited By ~ 1

Author(s):

Kirandeep K. Mann ◽

Arnold W. Schumann ◽

Thomas A. Obreza ◽

Jerry B. Sartain

Keyword(s):

Root Zone ◽

Digital Camera ◽

Soil Samples ◽

Shoot Length ◽

Tree Canopy ◽

Nutrient Concentrations ◽

Citrus Grove ◽

Canopy Volume ◽

Weed Cover ◽

Citrus Production

Citrus production in Florida is commonly affected by a high degree of spatial variability of soils. Therefore, this study developed rapid indicator crop bioassays to evaluate the relationships between indicator crops and citrus production at various soil depths. A citrus grove was divided into five productivity zones based on existing tree canopy volume using GIS software (“very poor,” “poor,” “medium,” “good,” and “very good”). Visual ratings of percentage cover were collected from each zone using a 1-m2 quadrant. Six random soil samples were collected between the tree rows from each productivity zone at four depths (0 to 15, 15 to 30, 30 to 45, and 45 to 60 cm). Greenhouse bioassay experiments used sorghum and radish crops grown in soil sampled from four depths. Overhead photographs of potted radish plants were captured periodically with a SLR digital camera to calculate leaf area by image processing. Shoot weights, shoot length, root weights, and leaf nutrient concentrations were measured at harvest (56 and 21 days after germination for sorghum and radish, respectively). Germination, shoot length, and shoot weight of sorghum and radish were significantly affected by the productivity zone. Sorghum (0 to 30 cm), radish (0 to 45 and 0 to 60 cm) and weed cover were strongly correlated (r ≈0.50 to 0.60***) with citrus yield and canopy volume at the lower two depths. The strong relationships (r > 0.50***) of sorghum and radish shoot weights and weed cover with soil properties at greater depths demonstrated the important role of cumulative root zone depth of 60 cm in differentiating citrus productivity. These results revealed that citrus production in poor areas of the grove was limited by the shallow depth of productive soil, and citrus productivity could be successfully mapped using indicator crop bioassays with soil samples taken at multiple depths.

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COMPARISON OF MODEL ACCURACY IN TREE CANOPY DENSITY ESTIMATION USING SINGLE BAND, VEGETATION INDICES AND FOREST CANOPY DENSITY (FCD) BASED ON LANDSAT-8 IMAGERY (CASE STUDY: PEAT SWAMP FOREST IN RIAU PROVINCE)

International Journal of Remote Sensing and Earth Sciences (IJReSES) ◽

10.30536/j.ijreses.2018.v15.a2845 ◽

2018 ◽

Vol 15 (1) ◽

pp. 81 ◽

Cited By ~ 1

Author(s):

Faisal Ashaari ◽

Muhammad Kamal ◽

Dede Dirgahayu

Keyword(s):

Remote Sensing ◽

Forest Canopy ◽

Near Infrared ◽

Vegetation Indices ◽

Single Band ◽

Tree Canopy ◽

Landsat 8 ◽

Swamp Forest ◽

Canopy Density ◽

Forest Canopy Density

Identification of a tree canopy density information may use remote sensing data such as Landsat-8 imagery. Remote sensing technology such as digital image processing methods could be used to estimate the tree canopy density. The purpose of this research was to compare the results of accuracy of each method for estimating the tree canopy density and determine the best method for mapping the tree canopy density at the site of research. The methods used in the estimation of the tree canopy density are Single band (green, red, and near-infrared band), vegetation indices (NDVI, SAVI, and MSARVI), and Forest Canopy Density (FCD) model. The test results showed that the accuracy of each method: green 73.66%, red 75.63%, near-infrared 75.26%, NDVI 79.42%, SAVI 82.01%, MSARVI 82.65%, and FCD model 81.27%. Comparison of the accuracy results from the seventh methods indicated that MSARVI is the best method to estimate tree canopy density based on Landsat-8 at the site of research. Estimation tree canopy density with MSARVI method showed that the canopy density at the site of research predominantly 60-70% which spread evenly.

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INFLUENCE OF DYNAMIC MAGNETIZATION TO IMPROVE THE EFFICIENCY OF ELECTROMAGNETIC-ACOUSTIC TRANSFORMATION WITH WAVEGUIDE CONTROL RODS

Devices and Methods of Measurements ◽

10.21122/2220-9506-2017-8-3-236-245 ◽

2017 ◽

Vol 8 (3) ◽

pp. 236-245 ◽

Cited By ~ 2

Author(s):

D. V. Zlobin ◽

L. V. Volkova

Keyword(s):

Acoustic Pulse ◽

Signal Amplitude ◽

Pulse Amplitude ◽

Bias Field ◽

Ultrasonic Waves ◽

Multiple Reflections ◽

Field Dynamic ◽

Low Efficiency ◽

Ema Method ◽

Dynamic Bias

The disadvantage of the electromagnetic-acoustic (EMA) method receiving ultrasonic waves are low efficiency. The traditional way to enhance its effectiveness is increase the bias field. The aim of the study was research the way to improve the efficiency of the EMA transformation, using a time-varying bias field.The researches held with the help of a specially designed installation that allows the magnetization to be performed by a constant and alternating magnetic field (dynamic bias), synchronously with the passage of the received pulse. The object of the study were rods made of different grades of steel with a diameter of 4–6 mm, in which the symmetrical zero mode S0 of the rod wave was excited by the EMA method (in the frequency range of about 40 kHz). A comparative analysis of the amplitudes and form pulses of multiple reflections during static and dynamic reversal of magnetization and with a full cycle of magnetization reversal conducted.The result of the efficiency measurements EMA reception during static and dynamic bias found a significant (up to 5 times) increase in the signal amplitude on the receiving transducer. Taking into account that the main contribution to the excitation mechanism and the reception mechanism made the magnetostrictive effect on low frecuncy, it can assumed that using a dynamic bias field is impacting significant on the effective mobility of magnetic domains (that is changes the dynamic magnetic susceptibility of the material). It is established that it is possible to monitor steel at lower values of the bias field, and, consequently, to reduce the mass dimensions of the magnetic system.Thus, in the course of the researchers found of effect of dynamic bias and effect of dynamic bias increase acoustic pulse amplitude of the signal of the received EMA method. Using this method will improve the quality EMA testing by creating more efficient EMA transducer. Taking into account that the value of the detected effect depends significantly on the steel grade, we can assume its possible application in the methods of express analysis, estimation of structural and stressed states.

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Variable-rate Spray Technology Optimizes Pesticide Application by Adjusting for Seasonal Shifts in Deciduous Perennial Crops

HortTechnology ◽

10.21273/horttech04794-21 ◽

2021 ◽

pp. 1-11

Author(s):

Lloyd L. Nackley ◽

Brent Warneke ◽

Lauren Fessler ◽

Jay W. Pscheidt ◽

David Lockwood ◽

...

Keyword(s):

Growing Season ◽

Variable Rate ◽

Pesticide Application ◽

Canopy Density ◽

Perennial Crops ◽

Constant Rate ◽

Canopy Volume ◽

Computer Controlled ◽

Spray Volume ◽

Adequate Coverage

To optimize pesticide applications to the canopies of deciduous perennial crops, spray volume should be adjusted throughout the year to match the changes in canopy volume and density. Machine-vision, computer-controlled, variable-rate sprayers are now commercially available and claim to provide adequate coverage with decreased spray volumes compared with constant-rate sprayers. However, there is little research comparing variable- and constant-rate spray applications as crop characteristics change throughout a growing season. This study evaluated spray volume, spray quality (e.g., coverage and deposit density), and off-target spray losses of variable- and constant-rate sprayers across multiple phenophases in an apple (Malus domestica) orchard and a grape (Vitis vinifera) vineyard. The variable-rate sprayer mode applied 67% to 74% less volume in the orchard and 61% to 80% less volume in the vineyard. Spray coverage (percent), measured by water-sensitive cards (WSC), was consistently greater in the constant-rate mode compared with the variable-rate mode, but in many cases, excessive coverage (i.e., over-spray) was recorded. The variable-rate sprayer reduced off-target losses, measured by WSC coverage, up to 40% in the orchard and up to 33% in the vineyard. Spray application deposit densities (droplets per square centimeter) on target canopies were typically greater in variable-rate mode. However, the deposit densities were confounded in over-spray conditions because droplets coalesced on the WSC resulting in artificially low values (i.e., few, very large droplets). Spray efficiencies were most improved early in the growing season, when canopy density was lowest, demonstrating the importance of tailoring spray volume to plant canopy characteristics.

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