Artificially induced air currents or air-assistance to droplet spectrum produced by hydraulic nozzles not only facilitate in transporting and depositing the droplets in different parts of canopy but also reduce the ap...Artificially induced air currents or air-assistance to droplet spectrum produced by hydraulic nozzles not only facilitate in transporting and depositing the droplets in different parts of canopy but also reduce the application rate of chemicals.The air streams increase the velocity of smaller droplets so that extra momentum would increase impaction and improve penetration into the crop as well as mitigating the influence of wind on drift.It is necessary to quantify the airflow characteristics.But,control of climatic and other conditions in the field is very difficult.Thus,airflow characteristics study was done under controlled conditions on a horizontal simulated crop canopy.Based on this study,an airflow distribution model was developed and airflow characteristics for vegetable crops,namely,eggplant,chilli and bittergourd were predicted.The differences between predicted and actual field study values were not statistically significant.Kinetic energy of air stream dissipated with its movement from top to bottom of the canopy.The rate of kinetic energy dissipation was higher in denser canopies.Higher air velocity 15 m/s was the best as it produced maximum turbulence throughout the canopy.展开更多
This paper presents a survey of image processing techniques proposed in the literature forextracting key cereal crop growth metrics from high spatial resolution, typically proximalimages. The descriptive crop growth m...This paper presents a survey of image processing techniques proposed in the literature forextracting key cereal crop growth metrics from high spatial resolution, typically proximalimages. The descriptive crop growth metrics considered are: crop canopy cover, aboveground biomass, leaf area index (including green area index), chlorophyll content, andgrowth stage. The paper includes an overview of relevant fundamental image processingtechniques including camera types, colour spaces, colour indexes, and image segmentation. The descriptive crop growth metrics are defined. Reference methods for groundtruth measurement are described. Image processing methods for metric estimation aredescribed in detail. The performance of the methods is reviewed and compared. The surveyreveals limitations in image processing techniques for cereal crop monitoring such as lackof robustness to lighting conditions, camera position, and self-obstruction. Directions forfuture research to improve performance are identified.展开更多
文摘Artificially induced air currents or air-assistance to droplet spectrum produced by hydraulic nozzles not only facilitate in transporting and depositing the droplets in different parts of canopy but also reduce the application rate of chemicals.The air streams increase the velocity of smaller droplets so that extra momentum would increase impaction and improve penetration into the crop as well as mitigating the influence of wind on drift.It is necessary to quantify the airflow characteristics.But,control of climatic and other conditions in the field is very difficult.Thus,airflow characteristics study was done under controlled conditions on a horizontal simulated crop canopy.Based on this study,an airflow distribution model was developed and airflow characteristics for vegetable crops,namely,eggplant,chilli and bittergourd were predicted.The differences between predicted and actual field study values were not statistically significant.Kinetic energy of air stream dissipated with its movement from top to bottom of the canopy.The rate of kinetic energy dissipation was higher in denser canopies.Higher air velocity 15 m/s was the best as it produced maximum turbulence throughout the canopy.
基金This survey forms part of the CONSUS program which is funded under the Science Foundation Ireland Strategic Partnerships Program(16/SPP/3296)and is co-funded by Origin Enterprises Plc.
文摘This paper presents a survey of image processing techniques proposed in the literature forextracting key cereal crop growth metrics from high spatial resolution, typically proximalimages. The descriptive crop growth metrics considered are: crop canopy cover, aboveground biomass, leaf area index (including green area index), chlorophyll content, andgrowth stage. The paper includes an overview of relevant fundamental image processingtechniques including camera types, colour spaces, colour indexes, and image segmentation. The descriptive crop growth metrics are defined. Reference methods for groundtruth measurement are described. Image processing methods for metric estimation aredescribed in detail. The performance of the methods is reviewed and compared. The surveyreveals limitations in image processing techniques for cereal crop monitoring such as lackof robustness to lighting conditions, camera position, and self-obstruction. Directions forfuture research to improve performance are identified.
