Posts Tagged: UC Davis
UC explores ladderless peach and nectarine orchards
Can shorter peach and nectarine trees reduce labor costs?
The answer may be developing soon at a 4-acre test orchard south of Fresno, where University of California researchers are planting semi-dwarfing rootstocks as part of a large, integrated experiment on virtually every aspect of peach and nectarine production.
“We're designing ‘ladderless' orchards, which have the potential to cut labor costs by 50 percent or more and improve worker safety,” said UC Cooperative Extension specialist Ted DeJong, a plant physiology professor at UC Davis. DeJong and Kevin Day, a Cooperative Extension farm advisor in Tulare County, are leading the extraordinary experiment.
Conventional peach and nectarine trees grow about 13 feet tall. Setting up, climbing and moving ladders to prune the trees and harvest fruit consumes about half the workday. Ladders are dangerous, too, which is why peach and nectarine growers pay about 40 percent more for workers' compensation insurance than growers who work with more low-lying commodities, like grapes.
Developed by breeders at UC Davis, the new rootstocks will produce trees that grow about 7 or 8 feet tall and can be pruned and harvested from the ground. With the right orchard management — which Day and DeJong will test at their plots at the UC Kearney Agricultural Research and Extension Center, near Fresno — the shorter trees could produce just as much high-quality fruit as their lofty kin.
“Ladderless orchards would be huge for our industry,” said Bill Chandler, who grows several varieties of peaches and nectarines on his 250-acre Chandler Farms in Selma, California. “There are so many costs associated with ladders that many growers are switching over to almonds just to stay in business. It costs me $1,400 an acre to thin our trees.”
“Even with conventional rootstocks, I prune my trees so workers can take two fewer steps on the ladder come harvest time,” he said. “And the savings are huge, even with that. It's important to keep farm work safe. And it's important to keep farming viable, or else we'll be getting all our produce from overseas.”
Shorter trees are just one of the elements of DeJong's and Day's experiment, which explores best practices for keeping peach and nectarine production economically and environmentally sustainable. Funded by the UC division of Agriculture and Natural Resources, their model orchard will integrate virtually every UC pomology advancement in the past 30 years.
You can read more at: http://www.caes.ucdavis.edu/news/articles/2014/08/ladderless-peach-and-nectarine-orchards-explored
UC Davis tomatoes provide year-round healthful eating for college students
At the same time, chefs and food buyers at universities, particularly the University of California, are selecting for high-quality fruits and vegetables, produced locally and sustainably. Universities with strong food sustainability programs are rightfully proud of what they're doing to educate students about food production, health, and nutrition. UC Davis Dining Services prioritizes the purchase of locally grown food (ideally within a 50-mile radius of campus). Most University of California campuses have similar programs.
At UC Davis, fresh roma tomatoes are picked each August from the 300-acre Russell Ranch, part of the campus's Agricultural Sustainability Institute, then processed within hours by campus Dining Services to provide year-round tomato sauce for pizza, pasta, and ratatouille. All told, 10,000 pounds of tomatoes are processed during a two-week period in August. About 29 percent of the total food served in the campus's residential dining halls is from local, organic or sustainable sources.
Emma Torbert, an academic coordinator at the UC Davis Agricultural Sustainability Institute, noted, “Connecting the food system to the research is really interesting. A lot of times there is confusion about where our food is coming from. The more people are educated, the more educated decisions they can make.”
Many UC Davis faculty and staff are so impressed with the food choices at the dorms that they purchase individual meal tickets and enjoy lunches made with the campus-grown tomatoes, herbs, and other vegetables, all of which are part of the daily food array. Public dinners are also offered periodically at the dorms so that community members can sit amongst students to taste and learn about the sustainability programs in the dorms.
Additional Information:
- Video: Farm to Table, UC Davis Tomatoes; 2010
- Slide show of this year's UC Davis tomato harvesting and processing system; 2014
- Sustainable Foodservice Progress Report 2014, UC Davis Dining Services
- Two videos of UC Davis students who work at the Student Farm to produce food, including one on tomato sauce production
- “Tomatoes: Safe methods to store, preserve, and enjoy.” UC Agriculture and Natural Resources, free publication
Tips for cattle health and safety during dry times
Water quality — Water is the most critical factor in the diet of food animals. When cattle don't drink enough clean and safe water every day, feed intake and productivity declines. Drought conditions can potentially affect all sources of water, including groundwater, but surface waters are especially vulnerable. It is important to frequently monitor water quality, especially as quantity becomes more limited, and test for basic water quality parameters such as total dissolved solids, sodium, sulfates, and nitrates/nitrites. Blooms of blue-green algae in water are also an issue. These cyanobacteria can produce toxins that can affect the liver and nervous system. Depending on the specific toxin and amount ingested, animals may die suddenly, or suffer from weakness, staggering, or photosensitization.
Feed quality and nutritional deficiencies — Drought conditions frequently result in the need to feed poor quality forages or to switch to alternative feed sources. Both can affect animal nutrition and increase the risk for intoxications. Use of poor quality forages can cause or exacerbate deficiencies of important minerals such as selenium, copper, and phosphorus and vitamins such as vitamins A and E. In addition, drought affected forages are often deficient in energy and protein. Even in non-drought years, deficiencies in selenium and copper are common in California cattle, particularly beef cattle. Copper deficiency causes reduced production, diarrhea, decreased resistance to infectious agents and parasites, poor vaccine response, loss of bone strength in calves, weakness and wobbling in neonates, reproductive failure, and sudden death of adult animals. Selenium deficiency also results in less resistance to infectious agents and parasites, and causes white muscle disease of skeletal and heart muscle resulting in stiff gaits, slow movement, heart damage and weak neonates. Primary vitamin A deficiency occurs in beef cattle on dry range pasture during periods of drought. Clinical signs include night blindness, dry eye, retarded growth rate, reproductive failures, and increased mortality. Maternal deficiency of vitamin A can cause abortions, stillbirths, or calves born alive but blind and weak that die within 1 to 3 days. Cows should be given an injection of vitamin A (and D) about 30 days prior to calving and calves should be given a vitamin A injection at birth.
Increased incidence of plant poisonings — Cattle will seek out and consume plants that they would not otherwise find palatable during drought conditions. Nitrate poisoning is one of the most common plant associated intoxications diagnosed by the California Animal Health and Food Safety Laboratory. The potential for nitrate poisoning to occur is increased when livestock water sources also contain elevated concentrations. The first sign of nitrate poisoning is often the sudden and unexplained deaths of one or more animals. Other clinical signs include drowsiness, weakness, muscle tremors, increased heart and respiratory rates, staggering, and recumbency. Signs can develop with several hours of ingesting a toxic amount. Nitrate concentrations can be easily and cheaply determined from samples submitted to a veterinary diagnostic laboratory for testing.
During periods of drought, cattle producers should be especially careful about the quality of feed and water available for their animals. Sick animals should be tested for various nutritional deficiencies and dead animals can undergo necropsies to determine cause of death so that other animals in the herd can be treated appropriately. Additional information and testing is available at the California Animal Health and Food Safety Laboratory System. For laboratory location and contact info, visit www.cahfs.ucdavis.edu. A longer, more detailed version of these tips may be found here.
Robert H. Poppenga and Birgit Puschner, veterinary toxicologists with the California Animal Health and Food Safety Laboratory System at UC Davis School of Veterinary Medicine, contributed to this article.
Connecting wildfires to climate change and drought
Longer summers, less moisture and warmer climates are predicted for California's Sierra Nevada mountains. These changing patterns bring frequent droughts and extended wildfire seasons — as seen from the current extreme drought. The question no longer is whether wildfires will be more common or more intense — they already are — but how forest managers want these fires to burn.
Jens Stevens, a postdoctoral researcher in disturbance ecology at the University of California, Davis, has tracked how forests thinned for wildfire react to high-intensity burns. The answers he found touch on growing concerns over how the state can protect its forests.
Under the context of climate change, Stevens studies how understory plants recover from wildfires, measuring the effects fuel treatments — such as the thinning of small trees — have on the way these forests burn.
Stevens' research showed fuel treatments encourage resilience to wildfires, giving forests a greater ability to withstand a burn. Under really hot, dry summer conditions this makes a powerful difference.
“If you get warmer temperatures you're going to dry out the fuels,” says Stevens. “If we want to retain forest-dominated landscapes, we don't have the choice of doing nothing, because eventually these stands are going to burn."
To preserve forests, Stevens looked to native plant diversity under each management strategy. After a high severity fire, the tree canopy is non-existent. This new high-light environment favors other species, such as shrubs and flowering plants, which crowd out young trees.
While the treatments do protect the forest and encourage plant diversity, they are expensive and lead to uncertainty over how sensitive wildlife species are affected. Yet these areas will burn eventually, Stevens argues. The choice is either a more open forest or no forest at all.
He points out research by UC Davis ecologist Malcolm North, which shows the current pace of treatments can't keep up with the extent of Sierra forests that have been fire suppressed. The US Forest Service can treat up to 40 percent of a forest before managers must start over for follow-up treatments. The other 60 percent doesn't get touched.
“So the only real way to address that is to let the fire do the work for you,” says Stevens.
The proposal North and his colleagues arrived at relies on “firesheds.” These fire-prone areas would have boundaries that allow officials to efficiently manage the fires. If a burn begins after a treatment, they don't put it out. Allowing the fire to burn fuels they would otherwise be removing frees up resources to treat other areas.
“So if it's going to burn,” says Stevens, “you need to figure out ways the fire's going to give you your desired outcome.”
Watch Stevens explain more in his seminar.
This post was adapted from a longer piece by the UC Davis Department of Plant Sciences.
Uncommon conundrum: When removing invasive species threatens endangered ones
Efforts to eradicate invasive species increasingly occur side by side with programs focused on recovery of endangered ones. But what should resource managers do when the eradication of an invasive species threatens an endangered species?
In a recent study published in the journal Science, researchers at the UC Davis examine that conundrum now taking place in the San Francisco Bay. The California clapper rail — a bird found only in the bay — has come to depend on an invasive salt marsh cordgrass, hybridSpartina, for nesting habitat. Its native habitat has slowly vanished over the decades, largely due to urban development and invasion by Spartina.
Their results, picked up by TIME magazine, showed that, rather than moving as fast as possible with eradication and restoration, the best approach is to slow down the eradication of the invasive species until restoration or natural recovery of the system provides appropriate habitat for the endangered species.
“Just thinking from a single-species standpoint doesn't work,” said co-author and UC Davis environmental science and policy professor Alan Hastings. “The whole management system needs to take longer, and you need to have much more flexibility in the timing of budgetary expenditures over a longer time frame.”
The scientists combined biological and economic data for Spartina and the clapper rail to develop a modeling framework to balance conflicting management goals, including endangered species recovery and invasive species removal, given budgetary constraints.
While more threatened and endangered species are becoming dependent on invasive species for habitat and food, examples of the study's specific conflict are rare. The only other known case where the eradication of an invasive species threatened to compromise the recovery of an endangered one is in the southwestern United States, where a program to eradicate tamarisk was canceled in areas where the invasive tree provides nesting habitat for the endangered southwestern willow fly-catcher.
“As eradication programs increase in number, we expect this will be a more common conflict in the future,” said co-author and UC Davis professor Ted Grosholz.
The scientists used data from Grosholz's lab as well as from the Invasive Spartina Project of the California Coastal Conservancy in their analysis.
Spartina alterniflora was introduced to the San Francisco Bay in the mid-1970s by the Army Corps of Engineers as a method to reclaim marshland. It hybridized with native Spartina and invaded roughly 800 acres. Eradication of hybrid Spartina began in 2005, and about 92 percent of it has been removed from the bay. The cordgrass has also invaded areas of Willapa Bay in Washington state, where efforts to eradicate it are nearly complete, and invasive Spartina has been spotted and removed from Tomales Bay, Point Reyes and Bolinas Lagoon in California.
The study, led by UC Davis postdoctoral fellow Adam Lampert, was funded by the National Science Foundation Dynamics of Coupled Natural and Human Systems Program.
Co-authors include UC Davis environmental science and policy professor James Sanchirico and Sunny Jardine, a Ph.D. student at UC Davis during the study and currently assistant professor at University of Delaware.
“This work is significant in advancing a general, analytical framework for cost-effective management solutions to the common conflict between removing invasive species and conserving biodiversity,” said Alan Tessier, program director in the National Science Foundation Division of Environmental Biology.