Posts Tagged: bacterial

When Monitoring Is the Best Action - The Case of Two “Flux Diseases”

[From the August 2016 issue of the UC IPM Green Bulletin] Two “sap flux” diseases...

It's Time to Prune Apricot & Cherry Trees

Although most fruit trees are pruned during the dormant season, in areas with wet winters, apricots...

Protecting California’s parsley crop

When most people think about parsley, they likely think of it as an inedible garnish a chef places on their plate. But parsley is widely used in dried spice mixes, soups and other prepared foods as well as in salads and other recipes. Currently, California produces almost 2,600 acres of parsley at a value of $18 million a year, with Monterey and Ventura counties accounting for 49 percent of the state's parsley production.

California parsley is produced typically in high volumes and with high quality. However in the past few years, growers began to observe unfamiliar disease issues in their parsley fields. Leaf spots, blighted foliage and yellowed plants contributed to loss of quality and reduced yields. Steven Koike and Oleg Daugovish, UC Cooperative Extension advisors in Monterey and Ventura counties respectively, stepped in to investigate the new parsley problems. They collaborated with farmers and pest control advisers to understand the extent of the problems and to obtain samples of the diseased crops. 

The UC Cooperative Extension plant pathology diagnostic lab in Salinas was successful in isolating and identifying several pathogens that were responsible for causing the disease symptoms. Working with USDA, they found that three new diseases were present in California parsley crops: bacterial leaf spot, Stemphylium leaf spot, and Apium virus Y disease.

Two of these problems are seedborne, so future management will include the use of pathogen-free seeds. The Apium virus Y pathogen is found in weeds, so growers will need to remove poison hemlock, among others.

Previous to this research, some growers were spraying symptomatic fields because they believed that a disease called late blight was responsible for the disease symptoms. Growers have now ceased making these sprays, eliminating the use of unnecessary chemicals and saving costs.

Click here for more on this research.

Biodigester turns campus waste into campus energy

More than a decade ago, Ruihong Zhang, a professor of biological and agricultural engineering at the University of California, Davis, started working on a problem: How to turn as much organic waste as possible into as much renewable energy as possible.

Last week, on Earth Day, the university and Sacramento-based technology partner CleanWorld unveiled the UC Davis Renewable Energy Anaerobic Digester (READ) at the campus' former landfill. Here, the anaerobic digestion technology Zhang invented is being used inside large, white, oxygen-deprived tanks. Bacterial microbes in the tanks feast on campus and community food and yard waste, converting it into clean energy that feeds the campus electrical grid.

“This technology can change the way we manage our solid waste,” Zhang said. “It will allow us to be more economically and environmentally sustainable."

It is the third commercial biodigester CleanWorld has opened using Zhang's technology within the past two years and is the nation's largest anaerobic biodigester on a college campus.

The system is designed to convert 50 tons of organic waste to 12,000 kWh of renewable electricity each day using state-of-the-art generators, diverting 20,000 tons of waste from local landfills each year. It is expected to reduce greenhouse gas emissions by 13,500 tons per year.

The READ BioDigester encompasses several of the university's goals: reducing campus waste in a way that makes both economic and environmental sense, generating renewable energy, and transferring technology developed at UC Davis to the commercial marketplace.

The biodigester will enable the more than 100 million tons of organic waste each year that is currently being landfilled in the U.S. to be converted to clean energy and soil products. The READ BioDigester is a closed loop system, moving from farm to fork to fuel and back to farm. Whatever is not turned into biogas to generate renewable electricity can be used as fertilizer and soil amendments — 4 million gallons of it per year, which could provide natural fertilizers for an estimated 145 acres of farmlands each day.

Nearly half of the organic waste, or feedstock, needed to operate the biodigester to full benefit will come from UC Davis dining halls, animal facilities and grounds. CleanWorld is working with area food processing and distribution centers to supply the remaining amount. Meanwhile, UC Davis will earn 100 percent of the project's green energy and carbon credits and receive all of the electricity generated.

Anaerobic digestion is an age-old process. However, Zhang's patented technology made it more efficient — capable of eating a broader variety and bigger quantity of waste, turning it into clean energy faster and more consistently than other commercial anaerobic biodigesters.

View a video about the UC David biodigester here:

(This blog post is condensed from a UC Davis news release about the biodigester.)

Additional information:

• Read the full press release
• Download biodigester photos
• Vine video: From lunch to lights
• Visit http://www.cleanworld.com/

Read more