Variable dose rate sprayer prototype for dose adjustment in tree crops according to canopy characteristics measured with ultrasonic and laser lidar sensor.

One of the key issues in crop protection products to be applied in tree crops is the dose rate adjustment. An inappropriate dose selection could be responsible of the lack of efficacy due to under dosage and a loss in efficiency due to over dosage. Both situations imply economical losses and greater impacts on the environment. A better dose adjustment is possible from a variable rate technology approach by measuring the crown volume and adjusting the dose rate on-the-go according to the variation of the estimated vegetation volume. Tests have been done with a variable rate sprayer prototype and satisfactory results have been achieved.Postprint (published version

Tree canopy volume measurement with ultrasonic sensors in fruit orchards, vineyards and citrus groves

Preprin

Obtaining the three-dimensional structure of tree orchards from remote 2D terrestrial LIDAR scanning

In recent years, LIDAR (light detection and ranging) sensors have been widely used to measure environmental parameters such as the structural characteristics of trees, crops and forests. Knowledge of the structural characteristics of plants has a high scientific value due to their influence in many biophysical processes including, photosynthesis, growth, CO2-sequestration and evapotranspiration, playing a key role in the exchange of matter and energy between plants and the atmosphere, and affecting terrestrial, above-ground, carbon storage. In this work, we report the use of a 2D LIDAR scanner in agriculture to obtain three-dimensional (3D) structural characteristics of plants. LIDAR allows fast, non-destructive measurement of the 3D structure of vegetation (geometry, size, height, cross-section, etc.). LIDAR provides a 3D cloud of points, which is easily visualized with Computer Aided Design software. Three-dimensional, high density data are uniquely valuable for the qualitative and quantitative study of the geometric parameters of plants. Results are demonstrated in fruit and citrus orchards and vineyards, leading to the conclusion that the LIDAR system is able to measure the geometric characteristics of plants with sufficient precision for most agriculture applications. The developed system made it possible to obtain 3D digitalized images of crops, from which a large amount of plant information – such as height, width, volume, leaf area index and leaf area density – could be obtained. There was a great degree of concordance between the physical dimensions, shape and global appearance of the 3D digital plant structure and the real plants, revealing the coherence of the 3D tree model obtained from the developed system with respect to the real structure. For some selected trees, the correlation coefficient obtained between manually measured volumes and those obtained from the 3D LIDAR models was as high as 0.976.This research was funded by the CICYT (Comisión Interministerial de Ciencia y Tecnología, Spain), under Agreement No. AGL2002-04260-C04-02. LMS200 and SICK are trademarks of SICK AG, Germany

Innovative LIDAR 3D Dynamic Measurement System to Estimate Fruit-Tree Leaf Area

In this work, a LIDAR-based 3D Dynamic Measurement System is presented and evaluated for the geometric characterization of tree crops. Using this measurement system, trees were scanned from two opposing sides to obtain two three-dimensional point clouds. After registration of the point clouds, a simple and easily obtainable parameter is the number of impacts received by the scanned vegetation. The work in this study is based on the hypothesis of the existence of a linear relationship between the number of impacts of the LIDAR sensor laser beam on the vegetation and the tree leaf area. Tests performed under laboratory conditions using an ornamental tree and, subsequently, in a pear tree orchard demonstrate the correct operation of the measurement system presented in this paper. The results from both the laboratory and field tests confirm the initial hypothesis and the 3D Dynamic Measurement System is validated in field operation. This opens the door to new lines of research centred on the geometric characterization of tree crops in the field of agriculture and, more specifically, in precision fruit growing

An Electronic Control System for Pesticide Application Proportional to the Canopy Width of Tree Crops

A prototype of an electronic control system based on ultrasonic sensors and proportional solenoid valves for a proportional application to the canopy width of tree crops was mounted on an air-assisted sprayer. The sprayer flow rate adjustment was based on the relationship between the actual tree width measured by the ultrasonic sensors and the maximum tree width of the orchard. The prototype was tested in olive, pear and apple orchards to assess the system performance in different crop geometries. The spray deposit distribution was measured in comparison with conventional air-assisted applications. Metal tracers were used so that spray deposits for each treatment could be measured on the same samples, reducing sampling variability. Liquid savings of 70%, 28% and 39% in comparison to a conventional application were recorded in the olive, pear and apple orchard respectively, which resulted in lower spray deposits on the canopy but a higher ratio between the total spray deposit and the liquid sprayer output (i.e. better application efficiency). A reduction of the maximum tree width parameter in the control algorithm in the apple orchard reduced spray savings but increased spray deposition, with spray savings mainly in the middle level of the outside canopy, compared to conventional air-assisted applications

Variable dose rate sprayer prototype for dose adjustment in tree crops according to canopy characteristics measured with ultrasonic and laser lidar sensor.

One of the key issues in crop protection products to be applied in tree crops is the dose rate adjustment. An inappropriate dose selection could be responsible of the lack of efficacy due to under dosage and a loss in efficiency due to over dosage. Both situations imply economical losses and greater impacts on the environment. A better dose adjustment is possible from a variable rate technology approach by measuring the crown volume and adjusting the dose rate on-the-go according to the variation of the estimated vegetation volume. Tests have been done with a variable rate sprayer prototype and satisfactory results have been achieved

Variable dose rate sprayer prototype for dose adjustment in tree crops according to canopy characteristics measured with ultrasonic and laser lidar sensor.

One of the key issues in crop protection products to be applied in tree crops is the dose rate adjustment. An inappropriate dose selection could be responsible of the lack of efficacy due to under dosage and a loss in efficiency due to over dosage. Both situations imply economical losses and greater impacts on the environment. A better dose adjustment is possible from a variable rate technology approach by measuring the crown volume and adjusting the dose rate on-the-go according to the variation of the estimated vegetation volume. Tests have been done with a variable rate sprayer prototype and satisfactory results have been achieved