- Author: Ben Faber
August 17 (1-3 PM)
Live Seminar and Hybrid Zoom Topic
Avocado Varieties Discussion
Speakers:
Mary Lu Arpaia - UC Riverside Extension Specialist/Plant Breeder
Avocado Varieties: Current status and crystal ball gazing towards the future
Consuelo Fernandez - Brokaw Nursery R&D Manager
Performance of Commercially Available Rootstocks and Future Availability of New Ones
Nathan Lurie and Panel
Grower Speakers on Avocado Variety and Rootstock Field Performance
NOTE: Seminar is In Person and Zoom (Hybrid)
To attend in person:
669 County Square Dr.
Ventura
To join the zoom meeting:
/h2>- Author: Karey Windbiel-Rojas
The UC Statewide Integrated Pest Management Program's website contains many useful features to help identify pests and problems in the garden and home. One such feature is the Weed Gallery, which contains hundreds of images and management tips for more than 150 common weeds found in California.
If you don't know what weed you are dealing with, the gallery will help you identify the plant using visual characteristics. First, narrow your search by selecting the weed category—broadleaf, grass, sedge, or aquatic plant (Figure 1). You will then see a collection of photos in that category.
Select the appropriate plant characteristic (Figure 2) to see another sub-menu of weeds that exhibit the traits of your weed. Scrolling over a thumbnail image on this sub-menu will bring up several photos of the weed—as a seedling, as a mature plant, its flower, and its seeds—to further aid in identification (Figure 3).
Once you think you've identified the weed, click on the link of the weed's name, which will take you to a photo gallery page where you can read about the weed's habitat, growth characteristics, and life stages (Figure 4). For many weeds, there is a link to a Pest Note that provides information about management, both chemical and nonchemical. In addition, each page in the gallery links to the Calflora website to show where the weed grows in California.
If you think you know the name of your weed, the gallery allows you to quickly access photos using common or scientific names to confirm identification. Just use the “List of All Weeds” link from the main weed gallery page.
The gallery contains other features as well:
- Want to know more about plants and their parts? Illustrated tutorials distinguish among broadleaf, grass, and sedge plants and define plant parts used in characterizing certain plant species.
- Need to identify common weeds found in lawns or turf? The broadleaf and grass categories link to a dichotomous key, where users can pinpoint common turf (and landscape) weeds.
- Didn't find your weed? See the weed identification tool under “More information” to search the UC Weed Research & Information Center (WRIC) technical weed key.
You can access the weed gallery page from the left-hand column on many pages on the UC IPM website or from the various weed-related pages within the website. To access the weed gallery directly, visit http://ipm.ucanr.edu/PMG/weeds_intro.html.
Eric Hamilton
Eric.hamilton@ufl.edu
Root-farming gophers might be our closest agricultural relatives
Although you'll probably never see them, you can spot them by the tell-tale mounds of sandy soil dotting a field: pocket gophers. Beneath your feet, the gophers continuously create and remold a labyrinth of winding tunnels hundreds of feet long.
And, perhaps, tend the world's most recently discovered farms. Root farms, that is.
A University of Florida biology professor and undergraduate student have discovered that southeastern pocket gophers tend to fields of subterranean roots they harvest for food. The discovery makes the rodents the only mammal — other than humans — known to farm for a living.
“They're providing this perfect environment for roots to grow and fertilizing them with their waste,” said Veronica Selden, who recently graduated from Florida with a degree in zoology and is the first author of the new paper.
The gophers' daily harvest of their root crops accounts for an average of 20% and as much as 60% of their energy needs, which helps make up for the intense energy cost of burrowing in dense soil. Selden and UF Professor Jack Putz published their findings July 11 in the journal Current Biology, where they argue that the root cropping behavior of the gophers constitutes a kind of rudimentary farming.
Enigmatic creatures, pocket gophers spend nearly their entire lives below ground in sprawling tunnels up to 500 feet long. Although often thought of as pests, they eat only roots and rarely damage crops. Nor do their strong tunnels undermine the ground.
“They live entirely alone in a tunnel system that's 100 meters long. Dark and wet like a sewer pipe,” Putz said. “The roots grow in like stalactites and stalagmites. They cover the walls of their tunnel.”
Indeed, sewers helped inspire the project. Putz and Selden were puzzling over how the gophers got enough energy to dig when they recalled the perennial problem of roots growing into sewer pipes in homes.
“If roots grow into these man-made tunnels, perhaps they'll grow into these gopher tunnels that have waste to fertilize them,” Selden said.
Fortunately for gophers, though, the roots are their main food source.
The project relied on ingenuity, collaboration and — in an homage to the gophers — a lot of digging. Out at the property where Putz lives, he and Selden spent months trying to keep gophers out of their tunnels so they could measure the roots that grew back in. Using dams of wood or metal, the researchers attempted to block the gophers from their tunnels, but to no avail — the gophers merely went around.
Eventually, Putz and Selden turned to 50-gallon drums with the ends cut off. After even more digging, the researchers placed the open side of a drum into the soil to surround a patch of gopher tunnels while allowing plants on the surface to keep growing. The cylindrical shape provided 360 degrees of protection from gopher interference. (The scientists note in their paper that, while gophers were certainly inconvenienced by the project, none were harmed.)
Calculating the daily rate of root growth allowed Selden and Putz, with help from UF biology Professor Emeritus Brian McNab and others, to calculate how much of the gophers' energy needs could be met by harvesting their crops.
They discovered that digging a tunnel costs far too much energy to be made up by the roots gophers eat while excavating. But, by harvesting the roots that grow into already-dug tunnels over time, the gophers can gain enough energy to keep digging tunnels in search of more food.
Although no other mammals are known to farm, other animals definitely do. Fungus-farming ants are perhaps the most famous. They sow and tend to fields of fungus and protect them from disease with antibiotics — much like how human farmers wield herbicides against weeds.
Unlike these ants, pocket gophers neither sow nor weed their crops. Indeed, while the gophers clearly harvest their crops of roots to survive, and take steps to defend and promote their crops, the new study reveals that the definition of “farming” is far from clear.
“Planting the crop, for some people, is what constitutes agriculture,” said Putz.
Yet many other animals, and also different human cultures, use horticultural techniques to tend to crops they don't plant themselves, Putz noted.
“I think the whole issue is intellectually exciting because it's not really settled,” he said.
Selden hopes the debate calls attention to the overlooked animals.
“Pocket gophers are a lot more interesting than people give them credit for. They're really important ecosystem engineers,” said Selden, who started her research career by pondering the habits of the rodents and has gone on to study the ecology of bats and bees. “They deserve more attention.”
Kym Pokorny - Oregon State University
Destructive Pest of Cherry, Grapes, Peaches, Blueberry, Fig and
Lots of Other Fruit
to Come Under Wasp Control?
Corvallis, Ore., June 6, 2022– After 12 years of research, a parasitic wasp that controls a highly destructive fruit fly will be released by Oregon State University agricultural scientists in June.
Vaughn Walton, Extension entomologist and professor in the College of Agricultural Sciences, said the U.S. Department of Agriculture has permitted release of the wasp (Ganaspis brasiliensis), a slow process that took more than 10 years from application to decision. Now that it has a permit, Walton's lab, which is part of the OSU Agricultural Experiment Station, is raising enough wasps to make a dent in the spotted wing drosophila (SWD, Drosophila Suzuki) population in Oregon.
“This will have a huge impact,” Walton said. “Spotted wing drosophila is very difficult to control. It's got a very, very high reproduction rate with many generations per year. Because of that, when using pesticides, they have to be applied constantly, sometimes two or three times a week. Growers are really interested and are excited about a biological control that will work along with cultural management tools to decrease SWD and not cost them any money. It's a natural resource available to them. We think this is going to change things.”
A holistic integrated pest management (IPM) approach that uses cultural controls like good sanitation, proper pruning, drip irrigation and weed cloth can be somewhat effective. But IPM management programs still need the addition of pesticides to fight spotted wing drosophila, Walton said.
Spotted wing drosophila, a tiny fruit fly that resembles those that hover over rotting fruit in summer, is well suited to the Willamette Valley climate. About 95% live in areas surrounding non-crop habitats that act as pest reservoirs for reinvasion of the crops. That's where the wasp will be released.
The adult female fly lays her eggs — up to 600 per year — within ripening fruit, said Ryan Chave, a graduate student who works with Walton. When the larvae emerge, they burrow in and start eating the fruit from the inside out, causing damage that results in severe crop losses.
The parasitoid wasp kills SWD by laying eggs inside the insect and when the wasp hatches, its larva consumes its prey, Chave said. Spotted wing drosophila populations can be kept at a bay at a rate of up to 65% when the parasitoid wasp is there to check it, according to preliminary data.
“We'll never take down the entire fly population,” Walton said. “But as SWD increases there's more food for the wasp. In the field if you have a bunch of SWD attack a crop and reproduce, as they increase there it gets larger and larger.”
Though not native to Oregon, a few of the parasitoid wasps were found in Oregon and allowed the researchers an opportunity to study them in the field. They're confident it will not become an invasive pest problem since G. brasiliensis is a specialist — in other words it only feeds on SWD, said Walton, who worked closely with Jana Lee of the Oregon Department of Agriculture. He also collaborated with colleagues at University of California, Berkeley. Walton has studied another Asian wasp (Pachycrepoideus vindemmiae) that has promise but not as much as G. brasiliensis because it's a generalist and will kill other insects in addition to spotted wing drosophila.
G. brasiliensis image: Dr. Kent Daane (University of California, Berkeley)
/span>- Author: Ben Faber
Check out the new citrus pest guide at UC-Integrated Pest Management - https://www2.ipm.ucanr.edu/agriculture/citrus/
Agriculture: Pest Management Guidelines
Citrus
University of California's official guidelines for pest monitoring techniques, pesticides, and nonpesticide alternatives for managing pests in agriculture. More
Year-Round IPM Program