Variable Rate Application Of Pesticides Research Articles

Advanced embedded generalized predictive controller based on fuzzy gain scheduling for agricultural sprayers with dead zone nonlinearities

Variable rate application of pesticides in agriculture can improve pest control and also increase food production. Nevertheless, incorrect spraying poses risks to the environment and human health, as well as may increase the total cost of production. Nowadays, it is quite known the importance of innovation in techniques and technologies to improve the spraying process in a variable rate application for pest control. This work presents a generalized predictive control (GPC) strategy to cope with nonlinearities. An extension of the stability analysis for constrained GPC controller for infinite horizons is also developed, which guarantees the stability of a fuzzy GPC for a limited variation of its tuning parameters λ and δ. Results show the usefulness in adding a fuzzy logic system, to cope with nonlinearities, leading to a conception of an advanced fuzzy GPC for a limited variation of its tuning parameters.

Agricultural rout planning with variable rate pesticide application in a greenhouse environment

The use of robotics in executing agricultural tasks has significantly improved productivity over the years as a result of automation in performing such activities as spray, harvesting, planting etc. In order to optimize both crop yield and quality while minimizing costs, there will be need for the application of navigation strategies. These will provide optimal as well as autonomous navigation capability which is built entirely upon field coverage plan thereby making robot navigation approach a paramount scheme. In this paper, the autonomy of an agricultural mobile robot is enhanced in a structured environment (greenhouse farm) to locate an optimum route such that the robot performs a selective and variable spray of pesticides to the plants. To realize this, a robust vehicle routing problem (VRP) scheme is designed to navigate the robot autonomously while making intelligent decisions to fulfil the pesticide demands at each node (infected plants). The improved non-dominated sorting genetic algorithm (INSGA-III) is adopted to solve this fully integer problem based on three (3) test cases carried out with 8, 32 and 56 infected plants respectively for validation. The results obtained show a trade-off solution as the Optimal INSGA-III is significantly lower than NSGA-III in terms of solution quality. On the other hand, a significant reduction in run times of between 66% and 76% and 76–93% was obtained for all test case scenarios for population sizes of 100 and 1500 respectively.

On-Farm Evaluation of Prescription Map-Based Variable Rate Application of Pesticides in Vineyards

Canopy characteristics are crucial for accurately and safely determining the pesticide quantity and volume of water used for spray applications in vineyards. The inevitably high degree of intraplot variability makes it difficult to develop a global solution for the optimal volume application rate. Here, the design procedure of, and the results obtained from, a variable rate application (VRA) sprayer are presented. Prescription maps were generated after detailed canopy characterization, using a multispectral camera embedded on an unmanned aerial vehicle, throughout the entire growing season in Torrelavit (Barcelona) in four vineyard plots of Chardonnay (2.35 ha), Merlot (2.97 ha), and Cabernet Sauvignonn (4.67 ha). The maps were obtained by merging multispectral images with information provided by DOSAVIÑA®, a decision support system, to determine the optimal volume rate. They were then uploaded to the VRA prototype, obtaining actual variable application maps after the application processes were complete. The prototype had an adequate spray distribution quality, with coverage values in the range of 20–40% and exhibited similar results in terms of biological efficacy on powdery mildew compared to conventional (and constant) application volumes. The VRA results demonstrated an accurate and reasonable pesticide distribution, with potential for reduced disease damage even in cases with reduced amounts of plant protection products and water.

Development of real-time laser-scanning system to detect tree canopy characteristics for variable-rate pesticide application

Improving pesticide application efficiency is increasingly important in orchard spraying. In this study, a laser-scanning system was designed to acquire gridding volumes of a tree to quantify the geometry characteristics of the tree canopy in real-time. A laser-scanning sensor mounted on a linear guide was utilized to measure the structure of a target tree canopy. A computer was used to receive measurement data from the laser scanner and obtain the movement distance of the laser-scanning sensor from a controller. An algorithm written with VC# program was designed to calculate gridding volumes of trees by recognizing valid measurement data from the laser scanner. Laboratory evaluations were conducted on three kinds of regular objects, and the maximum relative errors of section volumes of the cuboid, triangular prism and cylinder objects were 3.3%, 7.9% and 9.4%, respectively, which illustrated that the algorithm could calculate the section volumes in different parts of the objects with high accuracy. A conifer tree and an apple tree were chosen to verify detecting accuracy of the laser-scanning system at variable speeds and grid sizes. The variation coefficients of total volumes for each kind of the tree were 0.078 and 0.041, respectively, which indicated that the laser-scanning system could be applied to provide the gridding volumes of different canopy densities in real-time with good reliability for guiding a variable-rate sprayer. Keywords: laser-scanning system, sensor, tree canopy, variable-rate spray, pesticide application efficiency, gridding volumes, calculation algorithm DOI: 10.25165/j.ijabe.20171006.3140 Citation: Cai J C, Wang X, Song J, Wang S L, Yang S, Zhao C J. Development of real-time laser-scanning system to detect tree canopy characteristics for variable-rate pesticide application. Int J Agric & Biol Eng, 2017; 10(6): 155–163.

Real‐time plant image segmentation algorithm under natural outdoor light conditions

Variable rate pesticide application holds great potential in precision agriculture where application efficiency depends mainly on plant recognition. The segmentation of the plant from the background is key to plant recognition. The work presented in this paper is a real‐time segmentation algorithm that was developed to improve the quality of plant segmentation under natural outdoor light conditions. The plant images were greyed with the colour features H, a*, 13 and Cr respectively, and the plant was segmented from the grey images with a threshold that was computed by an iterative method. Experiments showed that segmentation was generally of good quality if the background was bare soil. The quality of segmentation declines if the images are greyed by H and Cr, and the quality remains stable if they are greyed by a* and I3 when the background is complicated, and, especially with heavy shadows. With respect to segmentation speed, that greyed by Cr was the fastest and that greyed by a* was slowest amongst the four.

Experimental Study of Droplet Transport Time between Nozzles and Target

Variable rate pesticide application holds great potential in precision farming with high efficiency of pesticide use and minimised environmental contamination, while application efficiency depends strongly on the accuracy of the discharge rate on the target area. This study is an initial part of the development of a variable rate sprayer to quantify droplet travel time with four types of nozzle at four different liquid pressures and at four forward speeds using a moisture sensor and laser technology. Performance of droplet deposition at different instants was investigated by moving belt and fluorescent tracer. Sprayer forward speed had a significant influence on droplet transport time, while liquid pressure had less influence. Sample positions chosen at below the nozzle and midway between two nozzles on the boom produced little difference in droplet transport time. Dynamic deposition results indicated that accumulated deposition at the peak point is 37·1%, 33·6% and 29·2% of the total deposition with a flat fan nozzle, low drift nozzle, and hollow core nozzle, respectively.