Viruses Aid and Abet to Overcome Plant Defenses
WSU researchers have found that viruses will join forces to overcome a plant’s defenses and cause more severe infections that an individual pathogen. “These findings have important implications in our ability to control these viruses,” said Hanu Pappu, Sam Smith Distinguished Professor of Plant Virology and chair of WSU’s Department of Plant Pathology. “Mixed infections are quite common in the field, and now we know that viruses in these mixed infections are helping each other at the genetic level to overcome host defenses and possibly lead to the generation of new viruses.”
Pappu published his findings in the latest issue of the journal PLoS ONE. Joining him are PhD student Sudeep Bag, and Neena Mitter, senior research fellow at Australia’s University of Queensland.
The researchers focused on iris yellow spot virus and tomato spotted wilt virus after Bag discovered that, when they infect the same plant, they helped each other overcome the plant’s defense response. Using sophisticated molecular techniques with guidance from Mitter, Bag found both viruses dramatically changed their genetic expression, breaking down the plant’s defenses and leading to more severe disease.
Bag also found that genes from the tomato spotted wilt virus seemed to “aid and abet” iris yellow spot virus as it spread throughout the plant and caused more disease. Growers should take this phenomenon into account, said Pappu, with broader management tactics that target more than one virus and possible variations.
The research was funded in part by the Specialty Crops Research Initiative of the National Institute of Food and Agriculture, a branch of the U.S. Department of Agriculture. The paper, “Complementation Between Two Tospoviruses Facilitates the Systemic Movement of a Plant Virus Silencing Suppressor in an Otherwise Restrictive Host,” can be found at http://bit.ly/RLhNoF.
Online Master’s in Food Science, Management
WSU is offering the nation’s first online master’s degree that combines food science expertise with management education. “The new food science and management option in WSU’s master of agriculture program opens the playing field for people with a background in food science wanting to move into management,” said Jeff Culbertson, food science professor.
Food scientists are in high demand nationally and internationally, Culbertson said. “We only graduate approximately 60 percent of the food scientists needed for the jobs available.”
The management section of the new offering includes courses on project management, bioethics, and personnel and human resource issues. The science portion includes course work that focuses on one of the most important issues in food science–sustainability.
“Issues like converting traditional waste streams into profitable products in food production are huge for the industry right now,” Culbertson said. “Having employees with the knowledge and expertise to make those kinds of transitions makes sense for food production companies both economically and environmentally.”
Other science courses in the degree program address food safety, principles of environmental toxicology, biochemistry and molecular biology. Several courses are being offered in partnership with the University of Idaho.
Those earning the degree must complete 12 credits in food science, 10 credits in statistics and research methods, and 8 credits of electives in management. Details are at http://bit.ly/foodsci-online. WSU also offers a “certificate of proficiency” in food science online. Information about that five-course program is available at https://online.wsu.edu/courses/foodscience. Information about other online programs offered through WSU’s Global Campus is at http://online.wsu.edu.
Tech Expo Offers Glimpse of Future Orchard Management, Harvest Tools
The recent technology expo hosted by WSU’s Center for Precision and Automated Agricultural Systems (CPAAS), rolled out a host of state-of-the-art machines and systems for improving orchard management and harvest efficiency. Visiting tree fruit growers and others at the expo saw demonstrations and presentations of technological solutions that are either prototypes or on the drawing board with prototypes on the horizon. Take a post-expo tour of the innovations with hosts from WSU Extension, CPAAS, the School of Electrical Engineering and Computer Science (EECS), and the Department of Biological Systems Engineering (BSysE).
Some of the innovations included:
Mechanical thinning systems: Karen Lewis, WSU Extension tree fruit specialist, discussed thinning equipment she and others have tested over several years. These include a prototype called the “Bonner” from the University of Bonn in Germany, a Darwin string thinner from German company Fruit Tec, a hand-held thinner developed by CPAAS for cherry canopies that will be made available commercially through a Chinese company, and a hand-held thinner from French company INFACO.
Multipurpose and harvest-assist platforms: Lewis described two types of driverless platform vehicles under evaluation by CPAAS that can help growers prevent ladder-related injuries in orchards and streamline management operations.
The Cascade, an all-electric, two-person platform vehicle, has adjustable wings for tasks such as string tying, tree training, and blossom thinning. “It’s working out to be a machine with good core technology that might solve some of our issues with efficiency,” Lewis said.
A 2011 DBR Conveyor Concepts four-person platform, built to Washington-specific growing conditions, was modified last winter with a “fantastic” LED light system, Lewis explained, which allows the machine to be used at night. Several bugs that last year caused bruising in fruit have since been eliminated. As a result, the Galas that were harvested this year “looked really nice in the bin,” Lewis said. Tests on early Fuji, a softer fruit, showed bruising in the second pick, however.
Bin transport system: CPAAS graduate student Yunxiang Ye introduced growers to a remote-control “bin dog” that loads and unloads bins during harvest. In field tests, the machine transported empty and full bins from a landing area 50 feet from the test orchard and back again in about three minutes.
Shake-and-catch harvest system: CPAAS graduate student Jianfeng Zhou presented information on prototypes being developed for shake-and-catch harvesting of sweet cherries. Zhou showed growers a hand-held limb shaker that can be used at frequencies from 10 to 16 hertz. The higher the frequency, the more pounds of cherries can be harvested per hour compared to manual harvesting alone.
Harvest management information system: CPAAS postdoctoral research associate Yiannis Ampatzidis and WSU Tri-Cities computer science master’s student Riley Wortman discussed a system for monitoring individual picker efficiency during sweet cherry harvest. The system uses two different digital scales for weighing bins or individual pickers, a radio frequency ID reader with wristbands for each picker, and a portable data logger attached to the picker’s belt. Weight totals, posted to the web, can be used to generate productivity reports.
The system is intended to improve payroll accuracy, Ampatzidis said. Currently, pickers are paid on a piece rate (i.e., by the number of buckets or bins they fill). “With this system, you can pay pickers by the pound,” he said.
Data visualization: WSU Tri-Cities computer science undergraduate Wesley Johnson introduced visitors to a prototype software analysis tool that provides growers with a visual representation of data gathered via sensors in their fields. The software processes canopy sunlight, temperature, soil moisture, and soil testing results, and makes them available through a web interface on a smart phone, tablet, or laptop. “You can make your farming decisions in the field or remotely, which will make your life a little bit easier,” Johnson said.
Cameras and other image-processing equipment: 3-D and other image-processing equipment were the subject of BSysE assistant professor Manoj Karkee’s presentation. Coupled with software, these imaging tools can potentially improve the accuracy of crop load estimation in apples, and help identify and locate branches for robotic pruning.
Light interception measurement: CPAAS graduate student Jingjin Zhang demonstrated a mobile sensor system for measuring canopy light interception in Y-trellis and upright fruiting offshoot architectures. The system consists of a utility vehicle, a data acquisition tool, and sensing equipment for measuring light. “We believe light interception has something to do with yield and fruit quality. The better the interception is, the better fruit you get, and the higher yield you get,” Zhang said.
Wireless irrigation control system: CPAAS graduate student Yasin Osroosh described how this system uses information from sensors placed around an orchard to measure soil moisture and canopy temperatures, both indicators of water status. Once processed, the system can decide whether a specific plot within the orchard needs water. A portable sensor suite also measures wind speed, air temperature and humidity, and light. “The data we get from this system tells us which part of the canopy is not irrigated sufficiently,” Osroosh said.
For related coverage on the CPAAS Technology Expo by Good Fruit Grower magazine, visit http://bit.ly/RarD65.