University of Florida

Research: Agricultural Production Engineering

Research projects in Agricultural Production Engineering.

Sensing Technologies For Precision Agriculture In Florida

Investigators: Lee, W. S.; Ehsani, M. R.; Burks, T. F.; Schueller, J. K.

It is well known that agricultural fields are not uniform, but rather show in-field spatial variabillity in many important factors for crop production, such as nutrients, water, pH, soil type, soil water content, organic matter content, etc. Traditionally growers were aware of these in-field spatial variabilities, however no technologies were available to deal with them. They treated the whole field uniformly when they applied nutrients, water, pesticides, etc., regardless of the variability. However, with the advances of technology, site-specific crop management (SSCM) or precision agriculture is becoming possible, and different locations in a field can be treated differently based on the site-specific conditions. Precision agriculture is defined as "managing each crop production input - fertilizer, limestone, herbicide, insecticide, seed, etc. - on a site-specific basis to reduce waste, increase profits, and maintain the quality of the environment" (Ess and Morgan, 2003). To implement precision agriculture for efficient crop management, growers need to know the status of crop and soil throughout the crop production periods from planting to harvesting. Once the crop status is known, growers can make correct management decisions, so that they can save time, labor, and money and thereby increase yield and profit. However, currently there are not many sensing systems commercially available for detecting crop status. Those existing ones are mostly for grain crops and tailored for grain production, and cannot be easily applied to crops grown in Florida. In 2007, Florida's major crops were oranges, grapefruit, snap beans, tangerines, sugarcane, fresh market tomatoes, bell peppers, cucumbers, and watermelons in terms of total value of production (Florida Department of Agriculture and Consumer Services, 2008). Certainly Florida has its uniqueness in crop varieties, and thus different sensing systems need to be developed to fit the crop situations in Florida. During the next five years, we are planning to develop different sensing systems that could help site-specific crop management for Florida's major crops, including citrus, sugarcane, and other high value crops. The sensor systems will have to be very user-friendly, so that growers could utilize them easily without much prior training or experience. These sensing tehnologies will be transferred and disseminated to Florida growers, and we would like to encourage them to adopt these developed technologies in their crop production so that they could implement precision agriculture, maintain competitiveness, overcome potential farm labor shortage, and increase overall yield and profit, while maintaining the quality of the environment.


The overall goal of this project is to develop sensing technologies for site-specific crop management in Florida so that growers can increase yield and profit and maintain the quality of the environment. Specific objectives are:

  • To develop sensing technologies for crop status including nutrient, water, disease, yield, and other crop information.
  • To evaluate the developed sensing technologies in actual crop production.
  • To combine the developed sensing technologies through sensor fusion toward the development of an integrated sensing system that can measure multiple crop information simultaneously.
  • To disseminate the developed technologies in Florida growers through various means (commercialization, website, extension publications, and trade magazines) so that they could adopt the technologies, increase yield and profit, and maintain the competitiveness of crop production.

Automation and Mechatronic Development
of Horticultural Production Systems

Investigators: Burks, T. F.; Castle, W. S.; Lee, W. S.; Boman, B.; Miller, W.; Roka, F.; Turner, A.

There is a growing interest among researchers, industries, and growers to pursue automation solutions to reduce the increasing disparity between U.S. production labor costs and those of developing countries. However, it is clear that novel approaches need to be taken to solve the technological problems, as well as the manufacturing and maintenance challenges which will surface as high-tech equipment systems are implemented in harsh agricultural environments. Past automation efforts have demonstrated that research efforts that jointly design the machine and plant systems have the greatest opportunity for success. Consequently, it is important to closely coordinate research in both areas. This program will combine research from two major Florida horticultural production applications (greenhouse spraying and citrus harvesting), which will provide a basis for building upon the fundamental technologies necessary to implement robotic solutions in horticultural production. Specific research in sensing technologies, manipulator configuration, visual servo control, end effector development and autonomous guidance systems will be pursued to advance these technologies as can be applied to the specific applications listed and eventually extended to other horticultural production systems. In addition, research in optimal grove and tree factor design will be integrated with machine systems development to improve the plant-machine system viability with regard to optimal production efficiency.


The overall goal of this project is to develop a real-time machine vision system for citrus yield mapping to manage grove site-specifically and to increase profit ultimately. More specifically, the objectives are to:

  • Evaluate VIS/NIR/FIR and other sensor technologies which are useful for selective fruit harvest, with appropriate sensor fusion, to improve fruit detection and enable the tree fruit grading by maturity and size.
  • Implement and improve visual servo control strategies which will be used to target and track fruit during harvest. Develop path planning strategies which will optimize harvesting time.
  • Develop novel end-effectors and manipulator arm configurations which will optimally harvest tree fruit.
  • Improve tree characteristics, orchard design, and cultural practices which will enhance the harvestability of citrus.
  • Develop robust vehicle guidance technologies for operation in orchards and greenhouses where traditional GPS based techniques are incapable of maintaining navigation information from satellites.

Integrated Systems Research And Development In Automation And Sensors For Sustainability Of Specialty Crops

Investigator: Lee, W. S

In order to manage the specialty crops efficiently (especially citrus in Florida), crop and soil status need to be identified at various stages of crop growth. Information for crop status includes water content, nutrients, disease, pest, crop biomass, plant/tree count, crop size and quality, yield, weed, etc. Soil characteristics include fertility, water content, pH, organic matter content, soil type, texture, etc. This information will be prioritized based on stakeholders input including specialty crop growers, extension agents as well as from literatures. Based on the prioritized needs, sensing systems will be investigated, designed, and developed with different sensing techniques including computer vision, spectral characteristics, ground and aerial based remote sensing, thermal imaging, sensor network, multispectral and hyperspectral sensing, etc. The information from individual sensors will be integrated and used to assist specialty crop growers after individual sensing systems are developed for different crop status, so that they can make efficient management decisions, reduce labor and input expenses, and increase yield and profit. For such purposes, mechanized and automated sensing systems will be most appropriate, considering the current labor shortage situation. Every effort will be made to commercialize the sensing systems developed from this project so that growers could benefit from using the systems developed.

Investigator: Ehsani, R.

The rapidly changing and very competitive agricultural market requires new and innovative farming strategies. Labor shortages, new pests and diseases have increased the cost of production and harvesting and put specialty crop growers in the U.S. at a disadvantage in the global market. The ultimate goal of this project is to increase the profitability of specialty crop production. New sensor technology such as microelectromechanical (MEMS), bioMEMS, nanotechnology, chemical and biological sensors along with advanced communication technologies such as wireless sensor networks can be used for better detection of pests and diseases and better management of risk factors. Also, similar sensors along with advanced automation techniques can be used in developing a new smart generation of agricultural equipment and harvesting machines for specialty crops. These goals can be met through multi-disciplinary and multi-state research. This project initiates a forum to discuss and collaborate on these topics with colleagues at different universities with similar interests.


  • Develop sensors and sensing systems which can measure and interpret the parameters
  • Design and evaluate automation systems which incorporate varying degrees of mechanization and sensors to assist specialty crop industries with labor, management decisions, and reduction of production costs
  • Work in partnership with equipment and technology manufacturers to commercialize and implement the outcomes of this project

Machine Enhancement For Citrus Mechanical Harvesting Equipment

Investigators: Ehsani, M. R.; Burns, J. K.; Lee, W. S.; Syvertsen, J. P.

TFlorida had 233,260 ha (576,400 acres) of citrus groves in 2006 and produced 7.8 million tons of fruit (NASS/USDA, 2007). Currently, the majority of citrus is hand-harvested. Citrus harvesting has been a labor intensive operation and labor shortage is a major issue for the citrus industry. The cost of harvesting Florida?s citrus now exceeds the total cost of production. Harvesting costs in Florida are almost twice that of Brazil, the main competitor for processed oranges. This major difference in harvesting cost, which mainly originates from the difference in labor costs, puts Florida citrus growers at a disadvantage in the global market. In recent years, new immigration laws and competition from other labor intensive industries such as construction has caused a significant labor shortage. The recent labor shortage substantially increased the need for cost effective mechanical harvesting systems and focused industry attention on mechanical harvesting technologies that can reduce the costs associated with harvesting. In general, there are two types of harvesting systems commercially used in citrus groves; continuous canopy shake and trunk shake systems. Both harvesting techniques come with or without a catch frame and are suitable for different sizes and shapes of orchards. The two systems can potentially increase the labor productivity by 5 to 15 times over a hand crew, thereby reducing the unit harvesting cost by 50% or more (Brown, 2005). Currently, the most commonly used mechanical harvesting systems in Florida are the Continuous Canopy Shake-Catch (CCSC) and the Tractor Drawn Canopy Shake (T-SC) systems. The productivities of these systems are much higher compared to trunk shaker systems because they can continuously harvest and they don?t need to stop to harvest each tree. However, they are not perfect and there are many areas in which these machines can be improved and enhanced. For example, current canopy shakers use a constant shaking frequency when operating in a given orchard. The overall goal of this project is to enhance the quality of these machines and to identify and propose solutions to remove issues that prevent adoption of these machines for citrus production in Florida.


The long term goal of this research program is to enhance the profitability and global competitiveness of citrus production in Florida by reducing citrus harvesting cost. The specific goals are:

  • To study the existing commercially available mechanical harvesting equipment such as continuous canopy shaking machines, fruit pick up machines, harvesting aids, and harvesting trucks to evaluate their field performance and to identify the ways and means of improving their efficiency.
  • To develop tools and equipment for evaluating the performance of mechanical harvesting machines and to study the vibrational characteristics of citrus canopy due to canopy shaker mechanical harvesters under laboratory and field conditions and with or without abscission compounds.
  • To study the effect of harvesting parameters on percent fruit removal and tree damage; also to determine the optimal harvesting parameters for a given orchard and tree variety.
  • To design and develop an automation system for existing mechanical harvesting systems that can increase the productivity of the operator while improve the overall quality of harvesting.

Enzyme Stabilization And Rapid Methods For Citrus And Fruit Juice Quality

Investigators:Reyes-De-Corcuera, J. I.; Goodrich-Schneider, R. M.; Rouseff, R. L.; Ehsani, M. R.; Etxeberria, E.; Brlanski, R.; Wang, N.; Danyluk, M. D.

Assuring the production and quality of US agricultural commodities, processed foods and beverages is vital to the country's security and market competitiveness. Fresh and processed foods need to be safe as well as nutritious and good tasting. Maximizing sensory attributes and nutritional value while retaining fresh-like quality and ensuring safety are requirements for all food processors eager to conquer diverse emerging markets. The goals of this project are (I) to carry out exploratory research on stabilization and activation of citrus and other food enzymes and (II) to develop new and improved methods for plant and food pathogen detection, quality assurance of food and beverage products. Pectic enzymes are used for viscosity reduction and yield increase in the fruit juice industry. Lipases are used in the production of natural flavors. Stabilization and reuse of enzymes has the potential to decrease production costs and increase productivity. The effects of high hydrostatic pressure (HHP) on enzyme activity will be characterized by applying HHP to pectic enzymes and lipases at different temperatrues. Faster and more accurate and automated quality methods are required in the food industry. This research will focus on developing novel sensors, biosensors or rapid assays to replace the current assays for pectinesterase and oil content in juice. Physical, biochemical and electrochemical strategies will be used. We also expect to develop biosensors for indirect rapid detection of food pathogens. Citrus Huanglongbing (HLB)is one of the most threatening citrus diseases in the world and it is gravely affecting Florida's industry. Rapid in-field diagnosis of the disease can help reducing its spread. Knowing the changes in metabolites present in infected trees can help understanding the mechanisms of infection. In this research we will focus on identifying biomarkers for rapid detection of citrus HLB. Based on these biomarkers, we expect to develop portable sensors or biosensors for rapid, in-field diagnosis of HLB. Outcomes. a) Improved understanding of the effects of HHP on enzyme catalysis and structure. b) Incorporation of research findings into two graduate courses taught by Dr. Reyes De Corcuera: Citrus Processing Technology and Food Kinetics. c) Quality assurance laboratories are expected to save time and improve product quality by implementing a faster PME activity method for fruit juices. d) A faster and more sensitive method to determine oil in juice is expected to reduce processing costs to citrus juice and oil processors by reducing assay time and providing feed-back process control and more accurate quality control. e) In-field determination of titratable acidity that citrus growers can readily and inexpensively adopt at harvesting and increase crop value. f) Rapid methods for Salmonella and E. coli O157:H7 detection in foods reduce assay time and minimize the likelyhood that contaminated or under processed foods reach the consumer, thus, minimizes foodborne disease outbreaks. g)In-field diagnosis of HLB is expected to help citrus growers mitigate the spread of this disease


Assuring safety, nutritional value and sensory attributes of foods is vital for the US food processing and agricultural industries. The goals of this project are (I) to carry out exploratory research on stabilization and activation of citrus and other food enzymes and (II) to develop new and improved methods for plant and food pathogen detection, quality assurance of food and beverage products. Most foods are very complex biological systems that undergo metabolic, chemical and physical changes from harvesting to processing. The specific objectives of this research are:

  • To characterize the kinetics of pectic enzymes and lipases, immobilized and in solution under different hydrostatic pressure and temperature conditions.
  • To develop electrochemical enzyme biosensors for selective quantification of fruit juice quality and plant metabolism.
  • To develop rapid methods for the determination of citrus oil.
  • To develop a rapid method for in-field determination of titratable acidity in non-climacteric fruit.
  • Identify biomarkers for rapid detection of citrus Huanglongbing.
  • To develop rapid methods for food microbiology.

Site-Specific Crop Management

Investigator: Lee, W. S.

Coordination of research and technology will be continued among different participating states through various meetings and conferences such as NCERA-180 annual meeting, American Society of Agricultural and Biological Engineers Annual meeting, and International Precision Agriculture Conferences as well as personal communications. Networking will be very important for researchers in different states and cooperation will be planned among them. The overall goal for this networking and cooperation will be to increase profit for growers while maintaining the quality of the environment. Through SSCM, this goal can be achieved. Different types of crops will be utilized to implement different technologies in different states. Technology transfer will be conducted by cooperation among researchers, growers, and extension agents. Participations to different conferences and meetings, coordination of response to the scientific challenges and intellectual opportunities will be carried out. In order to respond to increasing and volatile input, costs, and their effects on spatial crop management, sensing devices or systems to measure the current status of soil and crop would be essential. In this project, different sensing systems will be developed to implement SSCM for increasing yield and profit as well as to protect the environment. The sensing systems should be easy and convenient for growers to use for their crop production. Through research cooperation of different projects, collaborative research articles will be published in journals. Teaching materials will be shared with other instructors in other states such as base data, yield maps of different crops, teaching tips, software modules, different devices and machineries of SSCM, so that students can benefit the most from lecture and lab activities. In conferences and meetings, teaching sessions will be offered for sharing teaching tips and suggested modules.


  • Facilitate the continued coordination of multidisciplinary research and technology transfer on SSCM among participating states.
  • Use the activities of the NCERA-180 to coordinate a response to the scientific challenges and intellectual opportunities surrounding this concept.
  • Develop methodologies and relationships to respond to increasing and volatile input, especially fertilizer, costs and their effects on spatial crop management.
  • Continue to facilitate collaborative activities to accomplish scientific publication of research, develop and implement education and technology transfer projects, and the organization of symposia at regional, national and international meetings.
  • Improve the university and college educational and extension programs by bringing together the information from the various NCERA-180 members and sharing teaching modules.