Facebook
X (Twitter)
Reddit
Pinterest
Tumblr
Delicious
LinkedIn
StumbleUpon
Posts Tagged: Plant
Google Weed View? Professor trains computer to spot invasive weed
Algorithm for AI enables low-cost tracking of invasive plant
To manage johnsongrass, a noxious weed that crowds out cotton and sickens horses, farmers have tried herbicides, burning and hand-pulling. Now, researchers at University of California, Davis, have developed a more high-tech weapon against the invasive weed: artificial intelligence and machine learning.
Using photos from Google's Street View database, UC Davis researchers have tracked down over 2,000 cases of johnsongrass in the Western United States for a fraction of the cost and time that it would take to do drive-by or other in-person surveys. They call their tool Google Weed View.
The advancement could help land managers easily and quickly survey for other problem plants.
“Once the model is trained, you can just go and run it on millions of images from Google Street View,” said Mohsen Mesgaran, an assistant professor in the Department of Plant Sciences at UC Davis. “We have huge flexibility, and its capability can be scaled up very quickly.”
The technique can easily be extended to other plant species. All that is needed is to label the new item in Street View photos and train the algorithm to identify that object in the images.
By providing location information, Google Weed View also offers an opportunity to examine how climate affects the growth and spread of weeds and invasive plants at very large scales.
“I think it can be both useful for management and for people with interests in more basic questions in ecology,” Mesgaran said.
A colleague's query
Mesgaran began looking at using Google's photo database of roadways, streets and highways after Kassim Al-Khatib, a professor of Cooperative Extension in the same department, asked if he could survey Western states for johnsongrass.
Al-Khatib studies where johnsongrass grows, ways to manage it and how this perennial has evolved to be so prevalent and resilient. He's also working with scientists at the University of Georgia to decode the genome of johnsongrass, which is one of the top 10 most invasive weeds worldwide.
Johnsongrass can crowd out native plants, harbor pathogens and affect agriculture. It grows up to 7 feet tall with flowers that are green, violet, dark red or purplish brown depending on maturity, according to a UC Statewide Integrated Pest Management Program briefing page.
“Johnsongrass is a major weed not just in California but worldwide,” Al-Khatib said. “It's very difficult to control. It's a problem on vineyards. It's a problem for cultivated crops. It's a problem on orchards.”
Google Weed View allows for rapid, convenient scanning. It is continuously updated via everyday users with compatible cameras and images collected by Google. “Instead of a day of in-person driving, we can use AI to determine if johnsongrass is in a county or not,” Al-Khatib said.
Setting the parameters
To find the weeds, Mesgaran went to Google Street View, which hosts billions of panoramic photos. It didn't take long to find johnsongrass.
“The pictures are really good quality,” he said. “You can see plants and flowers.”
Street View's photos offer a 360-degree view, so in his request Mesgaran set parameters, based on street direction (bearing), to only see the side view. He also specified latitude and longitude, and other factors. To train the deep, or machine learning model, he chose Texas, where johnsongrass is prevalent.
A student sorted through over 20,000 images from that request to find pictures with johnsongrass and drew rectangular shapes around the weeds. They located 1,000 images.
The labeled photos were fed into a computer to train a deep learning algorithm capable of identifying johnsongrass in Google's images. The model was run again to capture potentially more images containing johnsongrass. These additional images were then labeled and used to further refine the model. With each iteration, the algorithm learned and became more accurate.
“This deep learning model was trained by these images,” Mesgaran said. “Once we had a semi-working model, we ran it against about 300,000 images.”
For Al-Khatib's request, researchers focused on 84,000 miles of main roads in California, Nevada, Oregon and Washington states. The team discovered 2,000 locations with johnsongrass.
Google Weed View cost less than $2,000 to purchase the images and teach the model. A traditional car survey to cover the same area would cost an estimated $40,000 in gas, hotel, food and other costs.
“In a matter of months, we came up with 2,000 records and I can do it for the whole U.S.,” Mesgaran said.
Next up? The entire United States.
This story was originally published on the UC Davis College of Agricultural and Environmental Sciences news site.
Perfect Timing for Publication of Important Research Paper on Root-Knot Nematodes
Perfect timing. Today, during the 62nd annual international conference of the Society of Nematologists, being held July 9-14 in...
An illustration from the PNAS paper: Rice infected by root-knot nematodes (stained in red). (Illustration by Shahid Siddique)
'A Lady in Red': Petal Pusher?
It wouldn't make the news, even if it were a "Slow News Day." "Lady in Red Climbs Neon-Pink Petals in Search of Aphids." Lady beetles,...
A lady beetle nestled in an ice plant blossom. (Photo by Kathy Keatley Garvey)
Let's climb! A lady beetle begins her ascent--up an ice plant blossom. (Photo by Kathy Keatley Garvey)
How am I doing? Am I doing this right? Lady beetle stops. (Photo by Kathy Keatley Garvey)
I did it! I climbed my Mount Everest and I'm about to descend. (Photo by Kathy Keatley Garvey)
Bugs-Plants-People Interactions at UC Davis Biodiversity Museum Day
Plenty of interactions occurred among bugs, plants and people at the 12th annual UC Davis Biodiversity Museum Day, a Super Science Day recently...
Three youngsters delight in moving wildlife around--a squirrel, a bear, a carpenter bee and a butterfly--at the Bohart Museum of Entomology during the 12th annual UC Davis Biodiversity Museum Day. (Photo by Kathy Keatley Garvey)
A boy raises his hand to ask a question as Professor Fran Keller of Folsom Lake College, a Bohart Museum of Entomology scientist, discusses arthropods, including the black widow spiders in the foreground. The occasion: the 12th annual Biodiversity Museum Day. (Photo by Kathy Keatley Garvey)
Miles Pickard, 4, listens as his mother, Marissa Pickard, points out a display at the Center for Plant Diversity at the 12th annual UC Davis Biodiversity Museum Day. (Photo by Kathy Keatley Garvey)
Alison Colwell, curator of the UC Davis Herbarium, lines up displays for the 12th annual UC Davis Biodiversity Museum Day. (Photo by Kathy Keatley Garvey)
Marlene Simon, curator of the Botanical Conservatory, points to a plant that needs pollinating. She is known as "The Plant Lady" on the TV program, Good Day Sacramento. (Photo by Kathy Keatley Garvey)
UC Davis Biodiversity Museum Day volunteer Anna Klestinec contemplates the plants in the Botanical Conservatory. (Photo by Kathy Keatley Garvey)
Fungi that causes pine ghost canker detected in Southern California trees
Pathogen native to U.S. but had not infected pines until recently
Fungal pathogens that cause die-back in grape, avocado, citrus, nut and other crops has found a new host and is infecting conifer trees causing pine ghost canker in urban forest areas of Southern California.
The canker can be deadly to trees.
Scientists from University of California, Davis, first spotted evidence that the pathogens had moved to pines during a routine examination of trees in Orange County. Over four years, they found that more than 30 mature pines had been infected in an area of nearly 100 acres, according to a report in the journal Plant Disease.
Akif Eskalen, a professor of Cooperative Extension in the Department of Plant Pathology at UC Davis, suspects drought and other stress conditions brought on by climate change weakened the tree species, making it more susceptible to new threats.
“We have been seeing this on pine trees for the last several years,” he said. “Our common crop pathogens are finding new hosts.”
Pine ghost canker – caused by the fungal pathogens Neofusicoccum mediterraneum and Neofusicoccum parvum – usually infects the lower part of a tree's canopy, killing branches before moving on to the trunks. This dieback in some cases can be deadly.
Points of entry
The pathogens infect a tree by entering through wounds caused by either insects such as red-haired pine bark beetles or pruning – meaning trees in managed or landscaped areas could be at risk. Another route is via tiny natural openings known as lenticels that fungi can make their way through, said Marcelo Bustamante, a Ph.D. candidate in Eskalen's lab who is first author on the paper.
Spores from the fungi can disperse and the higher the prevalence means an increased chance of transmission. Rain, irrigation water and humidity by fog can trigger the right circumstances for the spores to spread, he said.
“The detection of these pathogens in urban forests raises concerns of potential spillover events to other forest and agricultural hosts in Southern California,” Bustamante and others wrote in the report.
Dead branches can indicate a canker. Detecting the fungi is not an emergency but “people should keep an eye on their plants when they see abnormalities,” Eskalen said.
Cankers are localized areas on stems, branches and tree trunks that are usually dead, discolored and sunken. On bark, the spores can look like strings of discolored dots.
The lab has posted a brochure bout how to best manage wood canker diseases.
Tips include:
* Keep your trees healthy: Proper irrigation and maintenance will keep trees strong.
* Prune dead branches to reduce sources of infestation.
* Avoid unnecessary pruning; perform structural pruning only.
Karina Elfar, Molly Arreguin, Carissa Chiang, Samuel Wells and Karen Alarcon from the Department of Plant Pathology contributed to the paper, as did experts from Disneyland Resort Horticulture Department, State University of New York's College of Environmental Science and Forestry, UC Irvine and UC Los Angeles.
