A recent call about the poor control of marestail (horseweed, Conyza canadensis) to glyphosate (Roundup®) wasn't surprising, but that paraquat didnt do the trick was.  It turns out that there is multiple resistance to the materials.  If horseweed is resistant to glyphosate it is possibly going to be resistant to paraguat  which also means that hairy fleabane which has glyphosate resistance could also show resistance to paraquat.  A recent study reports on the increased Conyza resistance to paraquat (Distribution of Conyza sp. in Orchards of California and Response to Glyphosate and Paraquat, Moretti et al, https://doi.org/10.1614/WS-D-15-00174.1):

Resistance to glyphosate in hairy fleabane and horseweed is a problem in orchards and vineyards in California. Population genetic analyses suggest that glyphosate resistance evolved multiple times in both species, but it is unknown if resistance to other herbicides is also present. Two approaches of research were undertaken to further evaluate herbicide resistance in Conyza sp. in the perennial crop systems of California. In the initial study, the distribution of Conyza sp. in the Central Valley, using a semistructured field survey, was coupled with evaluation of the presence and level of glyphosate resistance in plants grown from field-collected seed. In a subsequent study, single-seed descendants representing distinct genetic groups were self-pollinated in the greenhouse and these accessions were evaluated for response to glyphosate and paraquat. Conyza sp. were commonly found throughout the Central Valley and glyphosate-resistant individuals were confirmed in all field collections of both species. The level of glyphosate resistance among field collections varied from 5- to 21-fold compared with 50% glyphosate resistance (GR50) of the susceptible, with exception of one region with a GR50 similar to the susceptible. When self-pollinated accessions from different genetic groups were screened, the level of glyphosate resistance, on the basis of GR50 values, ranged from 1.7- to 42.5-fold in hairy fleabane, and 5.9- to 40.3-fold in horseweed. Three accessions of hairy fleabane from different genetic groups were also resistant to paraquat (40.1- to 352.5-fold). One glyphosate-resistant horseweed accession was resistant to paraquat (322.8-fold), which is the first confirmed case in California. All paraquat-resistant accessions of Conyza sp. identified so far have also been resistant to glyphosate, probably because glyphosate resistance is already widespread in the state. Because glyphosate and paraquat resistances are found across a wide geographical range and in accessions from distinct genetic groups, multiple resistant Conyza sp. likely developed independently several times in California.

Coffee is one of the top 3 most traded commodities in the world. About 12 billion pounds of coffee are consumed each year worldwide. In the US, coffee consumption has been steadily increasing and today Americans average about 4 cups of coffee per day. The US coffee market is worth over $75 billion with 34,000 shops generating $21 billion in retail revenue. The average American consumer is becoming increasingly educated about coffee and many have become connoisseur. Producing dry coffee beans (Fig.1 #4 ) is in many ways similar to wine making because coffee can reflect the character of a variety. After harvest, the berries (a.k.a. cherry; Fig.1 #1) are fermented. During this process yeasts break down the mucilage (i.e., the flesh around the bean). The parchment (Fig.1 #2) that remains around the green beans (Fig.1 #3 ) is subsequently removed by dry milling before roasting.  Also just like for wine, coffee aroma profile and organoleptic properties are graded and referred to as a cupping score, which has been developed by the Specialty Coffee Association, a nonprofit, membership-based organization that represents thousands of coffee professionals (https://sca.coffee).

Coffee (Rubiaceae family) is concentrated in the tropics and subtropics. The genus Coffea has over 60 species of which C. canephora (a.k.a. Robusta) and C. Arabica are the most common ones. Arabica coffee is praised for its excellent cupping quality and consumers demand is high. The US coffee market is dominantly Arabica and imports mainly from Brazil but other importing markets include Asia. I had the privilege to be invited by Dr. Dzung Anh Nguyen at Tay Nguyen University in Dak Lak province, Central highland region of Vietnam, to educate myself about the art of growing coffee and its challenges. Vietnam produces 3 billion lbs of coffee beans annually on 1.5 million acres (95% Robusta and 5% Arabica) and exports about 0.4 billion lbs of coffee to the US, although its main market streams are Europe, Japan and Korea. This industry is valued at $4 billions, with over $3 billions to export. In Vietnam, Arabica yields about 1-2 tons per Ha at $4,000 per ton, whereas Robusta yield twice as much for half the price. France introduced coffee production in Vietnam around 1915. The culture of coffee is now anchored deep in this region and a corner stone of the local economy. The elevation of the central highland in Vietnam ranges from 1500 to 6,000 feet. Above 3000 feet, Arabica is grown and Robusta below that line. The acidic soil, rain pattern and high elevation provide a unique environment for Arabica coffee plants. In addition, high elevation limits the incidence and severity of coffee rust. This fungal disease is a major limiting factor to coffee production worldwide. Robusta is known to be more tolerant to the disease and can be grown at lower elevation where disease pressure is higher. Besides rust, coffee berry borer, nematodes and soil borne fungal pathogens can cause devastating losses in coffee growing regions. Invasive pests and diseases, global warning, water availability and quality are key variables that need to be factored into market projection growth and availability of the supply chain. According to the Australia's Climate Institute's, hotter weather and changes in rainfall patterns are projected to cut the area suitable for coffee in half by 2050.

In the US, Hawaii is the leading coffee producer with 38 million lbs of cherry on 7,000 bearing acres in 2017 (USDA Statistics). As a reference point, a pound of Kona coffee cost about $35-50 at a retail store. In California coffee is not a commodity but a niche market that produces rare and specialty coffee. This is the fastest growing segment of the US coffee market and it has been valued at over $40 billion. In the past decade, California has become a fertile region for coffee. There was currently about 30-farms and 30,000 trees but with projections of 60,000 in this upcoming year. Research led at UC Davis has provided valuable science –based information (including the Arabica genome sequencing) to coffee production under our climate. In collaboration with the UC Cooperative Extension and specifically Mark Gaskell, practical guidelines have been developed to optimize coffee production in our region that includes selection of adapted varieties, plant nutrition and irrigation needs http://ceventura.ucanr.edu/Com_Ag/Subtropical/Minor_Subtropicals/Coffee_/

Evidence suggests that the mesoclimate of southern California (i.e., where avocado is grown) provides enough heat and sunlight units to grow Arabica. California also offers the unique advantage of having no serious pests or diseases. Another major advantage is the use of automated and controlled irrigation because it has favored optimal fruit set and maturation. The only limiting factors can be alkaline soils and cold temperatures both of which can be managed by soil acidification (with sulfur and pit moss applications) and tree protection at the establishment of the orchard. Orchards of inter-planted coffees plants and avocado are common to provide shading. Likewise in the low lands of Vietnam robusta trees were inter-planted with pepper trees. This model also offers an economic advantage to maximize land surface and increasing profit. The California business model developed under the leadership of FRINJ coffee (www.frinjcoffee.com) and Good Land Organics (www.goodlandorganics.com) has boosted the local coffee industry. They have the ambitious goal to make California the world capital of specialty coffee. Adopting a science-guided approach has provided a solid foundation to make coffee farming lucrative. The start up costs for coffee production are the same as for avocado, but can be 3 times more profitable. In the current marketplace, specialty coffee price can range between $60-300 per pound (that's a $8-16 per cup). The quality of FRINJ coffee has received international recognition for its quality (it ranked 27^th for best coffee of 2015) and this storyline was highlighted in the New-York Times. (https://www.nytimes.com/2017/05/26/business/your-coffee-is-from-where-california.html).

Figure 3: Coffee farm in the US (top) and Vietnam (bottom). Coffee plants are inter-planted with avocado and pepper trees to provide shade for coffee and optimize land surface.

Forrest Gump believed life was like a box of chocolates – you never know what you're going to get inside.

It's much the same for graduate student Danielle Martinez, except she isn't reaching for tasty chocolates.

She's digging into coyote stomachs.

“It's just like opening your presents at Christmas,” said Martinez, with more enthusiasm than most people would muster after sifting through the half-digested contents of more than 100 coyote stomachs. “You really do never know what you're going to find.”

Martinez, who is getting her master's degree at California State University, Fullerton, is part of a larger research effort studying urban wildlife in Southern California. Niamh Quinn, a wildlife ecologist with the University of California Division of Agriculture and Natural Resources, is leading the project.

“It's a melting pot of crazy, unanswered questions,” Quinn said. “Southern California has huge coyote issues, and people who hate coyotes and people who love coyotes and they're literally living next door to each other.”

What's missing is some of the basic science needed to help people manage and co-exist with coyotes and other urban wildlife, and that's where Quinn and her colleagues are trying to fill in the gaps.

What Do Coyotes Eat?

There are a lot of basic facts about coyote ecology scientists just don't know, and one is their diet. While there have been scat studies where people pick through poo to see what they've eaten, Quinn said those have limitations.

“It's not the identification of the parts within the scat that are inaccurate,” she explained, “it's the identification of the scat itself. If you have a coyote eating a lot of dog food, its scat is likely to be mistaken for a dog's.”

And coyotes do eat everything, as Martinez can attest.

“I think the strangest thing I've found was a piece of a baseball,” she said. “And I've found parts of a shoe, straw wrappers and a piece of car seat once.”

The animals' diet matters because some coyotes are being killed by rodenticides put out to kill rats, which makes sense if coyotes eat a lot of rats. But do they?

“There was zero scientific evidence that coyotes eat commensal rodents,” Quinn said, referring to the three types of mice and rats that live in close proximity to humans – Norway rats, roof rats and house mice. “And if coyotes don't eat rats, how are they getting exposed to rodenticides?”

So far, the stomach contents have shown roof rats to be about 8 percent of the Southern California coyote diet.

“Coyotes are omnivores,” Quinn said. “They eat everything. So they could be picking up things that are already dead. We don't know.”

To figure out what those things are, Quinn's team collects a lot of coyote carcasses with the help of CalTrans, local police departments and professional pest managers. Each animal is autopsied and the stomachs saved.

Martinez empties the contents of those stomachs onto a screen and washes away the goop, then picks out bones and other identifiable parts onto small trays. She's become quite expert at identifying the coyote's last meal, from cats to rabbits to gophers. Another team member blends the remainder together for later DNA analysis.

And with 100 stomachs done, Martinez only has about 300 more to go.

The Problem with Rodenticides

 In 2014, the state of California restricted the use of four anticoagulant rodenticides to licensed pesticide applicators to try to reduce wildlife losses from unintentional poisoning. The state's Department of Fish and Wildlife has documented 400 cases of wildlife poisoning from rodenticides since 1994.

Quinn is trying to document how those happen.

“How does it get from the point of origin to the point of exposure?” she asked. “We know there's exposure to wildlife, but there's not a lot of science about how it happens. And if we don't know how it's broken, we can't fix it.”

So a second part of the research is to see just which critters do visit the bait stations that are commonly set out to control rats. Another member of Quinn's research team set up bait stations, loaded with bait but no poison, in the backyards of dozens of Southern California homes. Some were on the ground and some elevated on fences or trees, but all had cameras trained on them.

“In the first 30 days, we got rats and a possum, a skunk, an owl a coyote and even a bobcat,” Quinn said.

Integrated pest management can help control rodent pests. Steps like clearing away ivy and woodpiles can eliminate their nesting sites. Good sanitation can take away their food supply, and sealing up holes and cracks can keep them out of homes and schools and businesses.

But because small rodents can reproduce rapidly – they do breed like rabbits after all – Quinn believes some rodenticide use will be needed to keep populations in check.

“I really don't think California without rodenticides looks very good,” she said. “But we do need better educated professionals and better educated homeowners to reduce unintentional exposure.”

She also hopes to better understand if the wildlife poisonings are having a population-level effect, and if they're having sub-lethal effects.

Help Wanted: Coyote Hazers

A third area of research will begin this fall, and its focused on human-coyote interactions.

In this part of the study, Quinn's team are going to collar 20 coyotes in different communities and then let them settle back in to their normal routines. Using observations and GPS and accelerometer data collected by the collars, the researchers are going to get a picture of the animals' day-to-day activities and routines.

Then a dedicated group of community volunteers are going to annoy those coyotes.

“They are going to intersect with the coyote at some period in the day and start to scream at the coyote and wave their arms,” Quinn said.

Yelling and arm-waving is a form of wildlife hazing, and it's recommended now for people who encounter wild coyotes. But there's no science to show it's effective.

“Did the coyote run away with its tail between its legs, or did it approach or anything in between?” Quinn said. “With the collar data, we'll be able to see if their behavior changes. Do they change their routine so they intersect with humans less?”

That's the hope, but not the only possibility.

“They could become inured to the hazing,” Quinn said. “Or maybe won't react in the first place, and they should.”

What scientists do know is that human-coyote confrontations are increasing in Southern California, and that with the area's geography – large communities surrounded or bisected with wooded canyons – those interactions are inevitable.

“It's unrealistic to expect not to have an encounter with a coyote in Southern California,” Quinn said. “And it's a very emotional issue, and rightly so. People's pets are being eaten, and people are being bitten. We had three people bitten in a six-month period, and a bite by a wild animal should be a freak event.”

And while the researchers are hoping to find ways to modify the animals' behavior to reduce those encounters, Quinn believes humans' behaviors will change, too.

“Twenty years ago, nobody locked their doors and now everybody does,” she said. “And people used to walk their dogs off-leash and leave their pets in their backyards. But that may change.”

Furry Pests Present Unique Challenges

Coyotes and rats fall into a category known as vertebrate pests – literally pests with a backbone – and they present unique challenges for pest managers. There are no fan clubs or support groups for insect or disease pests like stink bugs or root rots, but there are for coyotes.

And wild horses. And feral cat colonies.

The Western Governors' Association, for instance, just included feral cats on its list of 50 invasive species that threaten Western ecosystems. Feral hogs, European starlings and the water-dwelling rodent nutria are also on the list.

“When you're looking at managing a species like wild horses, it's highly charged,” Quinn said. “I've had colleagues get death threats.”

And that's why there's such a need for good science. No one can develop an effective management practice if they don't know the basic ecology of the issue.

“I was hired to solve a problem, and man do we have a problem,” Quinn said. “It's like a huge mosaic puzzle, and I feel like I just have the first four pieces in the corners. Now we have to fill in everything between.”

http://westernipm.org/index.cfm/ipm-in-the-west/communities/learning-to-manage-and-live-with-coyotes-in-southern-california/

With the rains, and in those area where fire took out the competition, weeds are coming back in their glory.  Mustard has painted the hills yellow.  The question comes up, what to do about all that wild growth.  Mechanical control, such as discing or whipping can work great.  Sometimes chemical control is the only answer.  A recent request for an alternative to glyphosate (Round-up) control of marestail (horseweed, Conyza canadensis) which is similar to hairy fleabane (Conyza bonariensis), came to the office from a lemon grower. Glyphosate just wasn't controlling it.  And it's been a problem for a while, even in tank mixes with paraguat and old-line weed killer.  The alternative might be a newer material, such as saflufenacil (Treevix) which has been recently added to the herbicides that can be used on citrus. 

As always before doing "vegetation management" it's best to identify the plant that is the problem

Identify the problem plant (weed)

http://wric.ucdavis.edu/information/weedid.htm

or if you know what the plant is, go directly to a listing of the weeds

Listing of weeds, their biology and control

http://wric.ucdavis.edu/information/info_spec_weed.htm

• Susceptibility of Winter Weeds to Herbicide Control (9/08)
• Susceptibility of Spring/Summer Weeds to Herbicide Control (9/08)

Or you can go in reverse order and look at your tree crop and see what herbicides are listed

Listing of herbicides by tree crops, including avocado and citrus

http://wric.ucdavis.edu/PDFs/T&V_herbicide_registration_chart.pdf