- Author: Ben Faber
There has been a good overall discussion of herbicide resistance found in plants and how they can affect orchard management. Check out this presentation by UC Cooperative Extension Weedologist, Brad Hanson, in the "past Webinars" section:
https://ucanr.edu/sites/ucexpertstalk/
And read more about glyphosate resistance in orchards:
- Author: Belinda J. Messenger-Sikes
- Author: Karey Windbiel-Rojas
We all have our favorite products, whether it's laundry detergent, shampoo, or a pesticide you know works against the pests in your home or garden. But what happens when a company changes the ingredients in a product? Does it work, smell, or lather differently?
You may visit a store looking for a pesticide product by name, not realizing that several popular pesticide brands have recently changed their active ingredients (the materials in pesticide products that actually kill or repel pests). Not knowing the product has changed, it is likely you would not think about reading the new label to see if the directions have also changed. Because of these new active ingredients, you may actually need to use the products differently or take additional precautions. There might also be changes in the way pests are controlled.
Remember to always read and follow the label instructions. This is the best way to ensure you purchase the correct product for your pest problem and use the pesticide safely and effectively in the home, garden, and landscape. Below are three familiar pesticide products that have recently changed.
Sevin
Sevin (Figure 1) is a familiar insecticide brand name for home gardeners used to control insects in lawns, on ornamental plants, and on vegetables. Sevin and the active ingredient carbaryl are practically synonymous. Recently, the active ingredient in some Sevin products was changed from carbaryl (a carbamate) to zeta-cypermethrin (a pyrethroid).
For instance, the products Sevin Insect Killer and Sevin Lawn Granules now contain the active ingredient zeta-cypermethrin. This pyrethroid is less toxic to mammals but both carbaryl and zeta-cypermethrin are highly toxic to bees and aquatic species. The new label on Sevin Insect Killer states that it controls more pests than the old product containing carbaryl, which may seem great, but the product may also kill some of the good bugs like lady beetles (ladybugs).
Another very important difference is the time the products can safely be applied on fruits and vegetables before harvest (called preharvest interval or PHI). Following the PHI reduces your pesticide exposure when you eat the food. For fruits such as apples and peaches, the PHI for the zeta-cypermethrin Sevin is 14 days, but for the Sevin with carbaryl it's 3 days. For other fruits and vegetables, the PHI for the new Sevin label may be shorter than the carbaryl label. Again, check the label.
The Sevin Ready-to-use 5% Dust remains a carbaryl product for now. Some stores may still have containers of Sevin products containing carbaryl but as stock runs out, they are likely to be replaced with the new product.
Roundup
Another familiar pesticide name is Roundup, a product known historically for containing the herbicide active ingredient glyphosate. Monsanto, the manufacturer of Roundup, now produces an extensive line of Roundup products containing multiple active ingredients, rather than just glyphosate alone. Many of these products contain triclopyr or diquat in addition to glyphosate. Some don't contain any glyphosate at all (Figure 2).
Corry's Slug and Snail Killer
In 2012, the active ingredient of the well-known Corry's Slug and Snail Killer (Figure 3) was changed from metaldehyde to sodium ferric EDTA, but the general look of the product box didn't change. This relatively new active ingredient is less toxic and less attractive to dogs and still effective against snails and slugs. However, the amount users apply and how quickly it works both differ from the previous active ingredient. If you are familiar with the old product you may have noticed a change, but unless you read the label, you may not know why.
You can read more about sodium ferric EDTA in the March 2013 issue of the Retail IPM News.
Reading the Label
Since pesticide labels and contents change, remember to read the product label before each purchase and use. A key item to check when shopping for a pesticide is the active ingredient, like carbaryl or glyphosate, which will be found at the bottom of the front label. Directions for use and other precautions are essential label elements to read, especially if measuring equipment or protective gear such as gloves or goggles are needed. Sometimes the the amount needed for a given area or volume of water may have changed, so label rates should be checked before application.
For more information, see the short publication Garden Chemicals: Safe Use and Disposal.
/h3>- Author: Ben Faber
It really has gotten out of hand - Hairy Fleabane and Horseweed which are both Conyza weed species that have run rampant this year because of the extra rain. It's also because they have become resistant to glyphosate herbicide. The problem has shown up all over the US and other parts of the world. Gradually as resistance has grown and their resistant fairy seeds have floated wherever the winds go, the weed is having a field day everywhere in your backyard, in your orchard, in the sidewalk. It's not just abandoned areas, but in actively managed areas where Cal Trans is doing its best.
Citrus growers who have not used preemergents in years or never used them have turned to various cocktails to knock it out.
A good description of the biology and care of Conyza can be found at:
https://anrcatalog.ucanr.edu/pdf/8314.pdf
And we along with others have written about this problem in the past -
http://ucanr.edu/blogs/topics/index.cfm tagname=Conyza ,
http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=10648 ,
http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=20061
But this year has been exceptional in the ubiquity of this plant. Something more than glyphosate is called for at this point. Glufosinate is a postemergent herbicide somewhat similar to glyphosate in name only and more expensive. It is a broadspectrum herbicide that is effective with thorough coverage on younger stages of conyza and other weeds. It will take some learning to get the best effect out of it. Citrus growers have been able to use it for several years now and have enjoyed its effectiveness. We are currently working on an IR-4 registration (http://ir4.rutgers.edu/) for avocados. It is currently not registered for use in avocado.
Mature avocados are pretty good about controlling any weeds in their own orchards through ground shading and self mulching, but conyza has become a problem in young orchards. And this new herbicide could help.
- Author: Jeannette E. Warnert
Wilen recommends home gardeners use a swivel (or hula) hoe to scrape the surface and decapitate weeds. “It's a bit of exercise,” she said, "but you can do it so quickly, it's not a problem.”
Another weed control strategy is a thick layer of mulch, with does double-duty by reducing water evaporation from the soil surface, thereby conserving water. Wilen suggests a three- to four-inch layer of mulch be spread in garden beds and landscape borders before the weed seeds have a chance to germinate. Mulch blocks the sunlight weeds need to push through the ground.
Fabric weed barriers are useful for controlling particularly challenging weeds, like nutsedge. Wilen suggests covering the fabric with mulch for an aesthetically pleasing weed-free garden.
Though the common herbicide glyphosate (such as Roundup) kills weeds and is safe if used correctly, Wilen prefers using the swivel hoe. "It's just quicker and easier than pulling out the spray equipment," she said.
To learn more about managing weeds in your garden and landscape, visit the UC IPM website Weeds page.
- Author: Jeannette E. Warnert
Late last month, USDA once again deregulated genetically modified alfalfa. The action prompted extensive news media coverage, with many articles centering on outcry from organic growers who are not comfortable with the idea of GMO/non-GMO coexistence.
According to a DTN blog, UC Davis Cooperative Extension alfalfa specialist Dan Putnam said he doesn't believe the deregulation puts organic alfalfa at risk.
"I don't believe it is certain. I believe it is something we can manage and prevent," he said.
Putnam's research results on alfalfa cross-contamination were noted in a blog on The Atlantic. A 2008 study found that when a Roundup Ready alfalfa seed crop and a non-Roundup Ready hay crop were grown 160 feet apart, the rate of successful gene flow from GM seed crop to non-GM hay crop was 0.25 percent - considered a small risk.
Nevertheless, Putnam said USDA's deregulaton decision likely won't put the controversy to rest.
"There's no question the lawsuits will continue. They would probably continue regardless of whichever way they went," he was quoted.
News roundup
Here are a few news stories that appeared this week that touched on ANR:
Sumo citrus. LA Times freelance food writer David Karp introduced readers to a new citrus variety, the Sumo. "Think of a huge mandarin, easy to peel and seedless, with firm flesh that melts in the mouth, an intense sweetness balanced by refreshing acidity, and a complex, lingering mandarin orange aroma," Karp wrote. "I've tasted more than 1,000 varieties of citrus, and to me the Dekopon (Sumo) is the most delicious." The Citrus Clonal Protection Program at UC Riverside played a role in making the Japanese fruit available to Americans by cleaning imported budwood to be sure it is free of diseases, a process that took several years.
Garden recycling. The L.A. At Home blog in the LA Times outlined ideas for putting recyclables to work in the garden, gleaned from Yvonne Savio, the manager of the LA Master Gardener program. The post illustrates a compost bin made of rusty bedsprings, an old bathtub turned into an ornamental shade garden, aluminum roasting pans that were recycled into seed-starting trays and plastic water bottles that double as water channeling containers.
Cheaters never prosper. In a move aimed at ending cheating at farmers' markets, the CDFA is proposing a significant fee hike for vendors - from 60 cents to $4. The $4 fee would raise about $1.5 million annually, much of which would be used to hire full-time CDFA officers based in Northern, Central and Southern California to conduct farm and market inspections, according to the LA Times.
Creating jobs. The head of USDA's Rural Development office in California visited Santa Cruz County to offer her agency's help to create jobs, said a story in the Santa Cruz Sentinel. "As a nation we have hemorrhaged jobs," said Glenda Humiston. "The jobs we've lost, virtually none of them are coming back." Pointing to positive steps to alleviate the problem, she noted that the Center for Regional Change at UC Davis is studying ways to innovate financial systems to invest local money locally.
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