For centuries, farmers have used all the colors of the rainbow to assess their orchards: The bright pink of blossoms in springtime, the vibrant green of heathy leaves, the red blush on fruit ready to harvest.
However, there are wavelengths beyond what a typical human eye can see that also provide valuable information about the crop – including tree vigor, plant stress, water use and fertilizer needs.
UC Cooperative Extension agricultural engineering advisor Ali Pourreza is peering into these previously invisible colorations to create a virtual orchard that will quickly, easily and inexpensively allow farmers and scientists to manage orchards for optimum production.
To develop his first virtual orchards, Pourreza launched a camera-equipped drone over an orchard at the UC Kearney Agricultural Research and Extension Center in Parlier. As the drone flies over the trees, it snaps thousands of photos and, using photogrammetry and software that stiches the images together, makes a three-dimensional point cloud model of the orchard.
A computer program can make colors that are invisible to the human eye – such as near infrared, red edge and ultraviolet – into imagery that illuminates key crop health indicators. Near infrared indicates the amount of healthy foliage, plant vigor and crop type. If the trees have low near infrared values, it means the plants are under stress. Red edge indicates plant stress and nitrogen content. High red edge values indicate nitrogen stress and low water content in plant tissues.
Patrick Brown, a pomology professor at UC Davis, is planning to use the virtual orchard to map nitrogen use in citrus.
“We are currently working on developing models to help growers determine their fertilization demands and have been contrasting the results from real orchards with the virtual orchard,” Brown said. “We have already utilized the approach to contrast the estimates of tree growth and yield with whole tree excavations and harvests to help validate the virtual approach and provide a more accurate estimate of tree nitrogen demand.”
Ultimately, Brown hopes to develop a way for growers to rapidly and cheaply estimate the nitrogen demand of their orchards, monitor the status of their orchards and manage nitrogen fertilizer applications.
In addition to the color variations brought to light by the virtual orchard, the system provides detailed data on other aspects of the crop development.
“We can learn canopy height and width, the spacing between the trees, total leaf area, canopy density and the amount of shaded area in the orchard,” Poureza said.
This data is of interest to scientists studying plant development, soil health and irrigation.
For example, UCCE agricultural water management specialist Daniele Zaccaria is researching the impact of soil-water salinity on water use by pistachio trees in the San Joaquin Valley.
“In our on-going research study we are characterizing the functional relationships between soil-water salinity, canopy size and density and evapotranspiration of pistachio trees through the light interception by the canopy,” Zaccaria said. “We plan to work with Ali to see how the virtual orchard approach can represent that and simulate the physical process of soil evaporation and tree transpiration as a result of different canopy sizes and densities intercepting different amounts of solar radiation.”
Zaccaria said he also plans to deploy a similar approach to understand how different canopy sizes, planting densities and row orientations found in commercial citrus orchards in the San Joaquin Valley – from navel oranges, to mandarins and lemons – can affect the citrus water demand and use.
In addition to the rich data that scientists can glean from the virtual technology, Pourreza envisions many applications of this technology for farmers, including yield forecasting, blossom mapping, variable pesticide application and robotic harvesting.
The sweltering summer of 2017 has a silver lining. When the temperature rises above 104, brown marmorated stink bug population growth is significantly slowed, reported Debbie Arrington in the Sacramento Bee.
An invasive pest from Asia, brown marmorated stink bugs showed up in midtown Sacramento in 2013. Their spread to commercial crops has been a concern. The stink bugs feed on dozens of California crops, including apples, pears, cherries, peaches, melons, corn, tomatoes, berries and grapes, said Chuck Ingels, UC Cooperative Extension advisor in Sacramento County. Feeding on fruit creates pock marks and distortions that make the fruit unmarketable. In grapes, berries collapse and rot increases.
In 2014 and 2015, the bugs' numbers continued to rise. In early 2016, Ingels feared a population explosion, but a heat wave in July, with seven days at 100 degrees or higher, plus two days at 104, wiped them out.
“This year, BMSB started off at historic lows (since 2013),” Ingels said. “Then, the June heat wave hit and the population that was there plummeted. Most of our trap counts for the last few weeks have been at or near zero, whereas there's usually a peak in June. So, it seems to be proof that temperatures over 100 for extended periods reduces the population – probably especially eggs and nymphs."
Ingels and UC Davis entomologists are studying the connection between high heat and stink bugs in the lab, where the pest is exposed to extreme temperatures. One hour at 113 degrees killed all the bugs, but mortality was also high over 104 degrees.
California citrus farmers have their ears perked for all news related to Asian citrus psyllid (ACP) and huanglongbing (HLB) disease, but the very latest advances have been available only in highly technical research journals, often by subscription only.
UC Cooperative Extension scientists are now translating the high science into readable summaries and posting them on a new website called Science for Citrus Health to inform farmers, the media and interested members of the public.
“The future of the California citrus depends on scientists finding a solution to this pest and disease before they destroy the industry,” said Beth Grafton-Cardwell, UC Cooperative Extension citrus entomology specialist. “Our farmers want to stay on top of all the efforts to stop this threat.”
Grafton-Cardwell and UC Cooperative Extension biotechnology specialist Peggy Lemaux are the two scientists behind the new website. When scientists make progress toward their goals, Grafton-Cardwell and Lemaux craft one-page summaries with graphics and pictures to provide readers with the basics.
For example, the website outlines scientific endeavors aimed at stopping the spread of huanglongbing disease by eliminating the psyllid's ability to transfer the bacterial infection. This section is titled NuPsyllid, and contains summaries of three research papers including one by UC Davis plant pathologist Bryce Falk.
Falk is collecting viruses found in Asian citrus psyllid; so far he has identified five. He is looking into the potential to utilize one of the viruses as is or modify one of the viruses to block the psyllid's ability to transmit the bacterium. For example, the virus might out compete the bacterium in the psyllid's body.
Another focus of the website is HLB early detection techniques (EDTs). If HLB-infected trees are found and destroyed before they show symptoms, ACP is less likely to spread the disease to other trees. EDT research described on the website includes efforts to detect subtle changes in the tree that take place soon after infection, such as alterations in the scents that waft from the tree (studied by UC Davis engineer Cristina Davis), changes in the proteins in the tree (studied by UC Davis food scientist Carolyn Slupsky) and starch accumulation in the leaves (studied by UC farm advisor Ali Pourreza).
As more research is published, more one-page descriptions will be added to the website. The website contains a feedback form to comment on the science and the summaries.
As 10-year-old Dominic Vargas crouched on the ground, in a cage not much larger than himself, trying to forage for tasty treats (candy) on the woodland floor...CRASH! The cage door came falling down and he realized that he had inadvertently tripped a tiny fishing line in his efforts to reach that candy - he was now trapped. Dominic seemed to accept his fate with good humor, shrugging, smiling and getting to work on that candy. Wildlife biologist, Jessie Roughgarden, commented that Dominic will now be collared, tagged and measured before returning him to the wild ... or in this case his parents.
This seemingly terrifying experience is in fact all part of the new "Sustainable You - 4-H Summer Camp" held at the UC Hopland Research and Extension Center. Sustainable You is a five-day camp allowing students to experience science and nature while learning about ways in which to conserve the land, water, air and energy.
View Dominic's experience in this 44-second video:
The camp is conducted at three of the UC Agriculture and Natural Resources' Research and Extension Centers across the state and each center tweaks the curriculum to suit their landscape and the kinds of research conducted at their sites. At Hopland this means getting the chance to meet with wildlife biologists from the UC Berkeley "Brashares Lab," led by professor Justin Brashares. It's an amazing opportunity for these kids to meet and ask questions of scientists conducting experiments in the countryside that surrounds them. Dominic may not be collared, but more than 10 deer on the property went through the same experience last week (minus the candy) as they were carefully captured by researchers and fitted with collars to better understand their movements and population across the 5,358-acre center.
The young team of scientists enjoying summer camp were also working to understand what wildlife shares the landscape with them by setting wildlife cameras daily and improving their positioning and locations each day. Advice from Brashares and Jessie Roughgarden helped the students improve their chance of catching footage of raccoons, foxes and maybe even a mountain lion. Day one produced fox video footage and shots of raccoons feeling around in the last pools of creek water to catch some of the tiny young frogs currently in residence.
Hear what Ahmae saw on her wildlife camera in the 59-second video below:
Exposure for these kids not only to hands-on activities exploring sustainability, but also to wildlife biologists, young researchers and professors working on today's wildlife and land management challenges, gives them an open door to explore their own future careers and interests.
As 9-year-old Ahmae Munday so sweetly put it, when asked what her favorite part of the Sustainable You Summer Camp was, "Everything! Especially the cameras."
The UC ANR network of Research and Extension Centers provide the perfect location to offer exposure to youth and communities to better understand and interact with the science going on in their own back yards and to inspire the next generation of researchers - as camp attendee and scholarship recipient Kaiden Stalnaker described in his scholarship application, "When I grow up I dream of a career in science and your camp would be a boost in the right direction."
Thanks to the researchers, camp counselors and students who have allowed the Sustainable You summer camp to inspire young people like Kaiden.
Summer brings an abundance of luscious and healthy fruits and vegetables. It's easy to buy more than we can eat, which sometimes results in #foodwaste.
In a guest blog post for the UC Food Observer, UC researcher Wendi Gosliner (part of the team at UC ANR's Nutrition Policy Institute, a cutting-edge unit that's using research to transform public policy) shared this observation:
“Food waste presents a major challenge in the United States. Estimates suggest that up to 40% of the food produced nationally never gets consumed, causing substantial economic and environmental harms. Wasted food utilizes vast quantities of precious land, water and human resources, yet rather than nourishing people, it feeds landfills, producing methane gasses that poison the environment. Much of the food waste (43%) occurs at the household level."
What history can teach us
Here's my take on food waste. It goes back in part to lessons I've learned from studying World War I (WWI), when the American government set food conservation goals (along with goals for local food production via Liberty – later Victory – Gardens). I'm a big proponent of both reducing food waste and producing more food in communities via school, home and community gardens. Big point: the World War I poster included in this post has advice we'd be well served to heed today.
It's an iconic poster from World War 1. Food…don't waste it. The image is regularly shared on Twitter and Facebook.
Period piece or photoshopped image?
The original was produced in 1919 by the United States Food Administration, under the direction of the newly appointed food “czar” – Herbert Hoover.
The poster was reissued during World War II. It's been revised in recent years by individuals and organizations interested in encouraging an ethos incorporating local foods and sustainability.
While I'm the UC Food Observer, I also dabble in the history of wartime poster art. I'm often asked if this is a contemporary mock-up made to look and feel vintage.
It's not a mock-up. It's the real deal, produced 95 years ago, with messages we should embrace today.
The original poster: Yes: ‘buy local foods' is rule 4
The original poster has six rules that we'd be well served to follow today. The fourth rule – buy local foods – is somewhat of a surprise to people today, because the notion of buying local seems somewhat modern. But in WWI, the U.S. government encouraged the local production and consumption of food, in part, to free trains to more effectively ship troops and war matériel.
Tackling food waste through preservation: today's Master Food Preserver Program
Many land grant institutions, including the University of California, host master food preserver programs. These programs teach best practices on food safety and preservation to volunteers. The extensive training program prepares the volunteers to work in their community educating others on the safe practices of food preservation, including pickling, drying, freezing, canning and fruit preserves.
Thinking about gardening? Do we have resources for you!
The University of California sponsors the state's Master Gardener Program, which fields more than 5,000 volunteers in communities across the state. The Master Gardener Program is a national program, housed at the land grant institution in each state, but it's also connected to the USDA. Free gardening resources are available here. Advice to grow by…just ask.
Food waste is both an ethical and environmental issue. It should concern us that we waste nearly 40% of the food we produce and purchase in this food-abundant nation.
For an interesting comparative statistic, consider this: our nation produced about 40% of the fruits and vegetables we consumed on the American home front in World War II in school, home, community and workplace gardens. That was the result of the iconic Victory Garden program (which actually got its start in WW1).
Three messages then: participate in the national effort, commit to wasting less food, and if you can, produce some food of your own.
Notes: There are many additional resources about #foodwaste.
Read: Dana Gunders of the National Resource Defense Council authored a 2012 report called Wasted that sparked much of this work. Dana also authored a book called Waste Free Kitchen Handbook: A Guide to Eating Well and Saving Money by Wasting Less Food, both of which are great reads.
Read this piece about the relationships between food, farming and the environment (including food waste).
Eating what's on your plate is one of the best ways to tackle climate change. View this episode of Climate Lab, a six-part series produced by the University of California in partnership with Vox.