- (Focus Area) Natural Resources
- Author: Ryan Hill
- Author: Marcelo Moretti
Introduction:
Pollinator insects are essential to produce many economically and nutritionally important crops grown in the western USA. These crops include blueberries, almonds, sunflowers, cucurbits, and many others. Almond pollination in California plays a vital role in the apiary industry, driving beekeepers to haul huge numbers of bee colonies to California for the few weeks in late winter when almonds bloom. Bees are selective of the pollen and nectar they forage, and diverse floral resources can allow bees to forage according to their nutritional needs (Leponiemi et al. 2023). Planting pollinator habitat in natural areas, gardens, and agricultural land is one method of supporting bee health. Irrigated agricultural land in the western USA can be an excellent resource for bees during the dry summer when flowers are rarer. However, the resident weeds in these settings are often not of high nutritional quality for hungry pollinators. To make matters worse, pollinator habitat in agricultural fields can be choked out by competition from weeds. Our control plots from these studies (Figure 1) demonstrate that point effectively.
Figure 1: Control plots at all three experimental sites were extremely weedy. This sometimes meant that none of the planted species could grow, as seen in the pictures above.
Objective:
The studies described here attempt to use herbicides to improve the chances for success in pollinator habitat establishment.
Methods:
Three locations in Oregon's Willamette Valley were selected for studies. Two were hazelnut orchards watered with drip irrigation, and one was a field plot set up for sprinkler irrigation. Each location received different soil preparation. The first orchard location (Corvallis) was not tilled, and soil compaction issues were present. The second orchard location (Amity) was power-harrowed, so the top two inches of soil were loosened. The third location (Lewis-Brown Research Farm) was plowed and disked.
All three locations were seeded in the fall with a set of flowering species with potential for pollinator habitat (Table 1).
Table 1: Species and seeding rates used for pollinator habitat establishment in Oregon's Willamette Valley. |
||
Common Name |
Scientific name |
Lb/Acre |
Hairy vetch |
Vicia villosa |
60 |
Lacy Phacelia |
Phacelia tanacetifolia |
12 |
California poppy |
Eschscholzia californica |
8 |
Farewell to spring |
Clarkia amoena |
2 |
Globe Gilia |
Gilia capitata |
2 |
Sweet alyssum |
Lubularia maritima |
2 |
These species were planted in rows, and herbicide treatments were applied over the top perpendicular to planting rows (Table 2). Four herbicides were applied post-emergence, and the rest were applied one day after planting (pre-emergence). Glyphosate treatments were only included in the orchard trials. Experimental plots were set up as a randomized complete block design with four replicates, and each species was treated as a separate experiment. A crop oil concentrate at 1% v/v was included for Motiff (mesotrione) and Basagran (bentazon), while a nonionic surfactant at 0.25% was included for Matrix (rimsulfuron) and Quinstar 4L (quinclorac). All post-emergent treatments (and glyphosate) included ammonium sulfate (AMsol 1% v/v).
Table 2: Trade name, active ingredient, and rate of herbicides applied to pollinator habitat species. Pre-emergent herbicides were applied at planting, and post-emergent herbicides were applied 30 days after crop emergence. |
||
Trade name |
Active Ingredient |
Rate (product/A) |
Pre-emergent treatments |
|
|
Cornerstone Plus |
Glyphosate |
3 qt |
Alion |
Indaziflam |
4 fl oz |
Trellis SC |
Isoxaben |
21 fl oz |
Devrinol 2XT |
Napropamide |
8 qt |
Chateau SW |
Flumioxazin |
6 oz |
Prowl H2O |
Pendimethalin |
6.3 pt |
Princep |
Simazine |
4 qt |
Motiff |
Mesotrione |
6 fl oz |
Post-emergent treatments |
||
Motiff |
Mesotrione |
6 fl oz |
Matrix |
Rimsulfuron |
4 oz |
Quinstar |
Quinclorac |
12.6 fl oz |
Basagran |
Bentazon |
2 pt |
In Amity, competition from perennial grasses resulted in poor stand establishment. A grass-selective herbicide (clethodim) was used, and the site was reseeded six months after the initial planting when soil conditions were appropriate.
Results and discussion:
Site differences.
Drastic differences were seen between sites. Table 3 shows how crop coverage differed between the three sites for each species.
Coverage at the Corvallis site was deficient for all species except hairy vetch.
Several species did very well at the Amity location. Phacelia in the glyphosate plots was exceptionally well established due to glyphosate's good control of perennial grasses that were not killed by the power harrow.
Lewis-Brown (LB) plots had the best crop establishment initially. However, this location had intense pressure from perennial weeds, so the initial crop establishment did not translate to superior pollinator habitat. The plots at LB where Alion was applied produced a good stand of Canada thistle (Cirsium arvense) by the end of the trial, which the bees loved.
Table 3: Crop Coverage for each species at each location is shown here. The values reported are from the treated plots with the highest coverage. |
|||||||
% Crop coverage (Best treatment) |
Site |
Vetch |
Phacelia |
Poppy |
Gilia |
Clarkia |
Lobularia |
Plowed and Disked |
Lewis-Brown Research Farm (LB) |
100 |
100 |
75 |
84 |
97 |
98 |
Power harrow |
Amity |
55 |
81 |
47 |
47 |
34 |
47 |
No tillage |
Corvallis |
89 |
11 |
28 |
0 |
15 |
0 |
Pre-emergent treatments
Pre-emergent herbicides often had inconsistent pollinator species safety; however, several combinations seemed safe. Napropamide was safe for Phacelia, Gilia, Clarkia, and Lobularia, while flumioxazin and pendimethalin were safe for poppy (Table 5). All five species only had adequate crop establishment at two of the three locations. Hairy vetch establishment was improved by simazine applications at all three locations, but crop coverage was not significantly different from the untreated control for this species (Table 5). Figure 2 shows the treatment by species combinations that were sometimes safe versus the combinations that were consistently safe for the planted species.
At the two orchard sites, glyphosate treatments were the best for Gilia, Phacelia, and poppy establishment (Table 5).
All three trials were conducted on fine soils with organic matter content ranging from 2-7% (USDA-NCSS soil survey). The safety of pre-emergent herbicides for pollinator species establishment may vary depending on soil characteristics.
Post-emergent treatments
Post-emergent (POST) applications were challenging to evaluate for safety. Weed control efficacy was inadequate, and so often, crop establishment was not good enough to confidently assess crop injury.
One exception was hairy vetch. This species exhibited good tolerance to a post-emergent application of Basagran, a result seen at all three locations. The results from two trials suggest that Clarkia tolerated POST applications of Quinstar. Not enough data were collected to conclude the other four species. See Table 4 for crop coverage data.
Conclusions
Site preparation was an essential consideration in our study. Soil compaction and perennial weed pressure must be addressed to have a successful pollinator habitat planting. It was also clear that pre-emergent herbicides can improve habitat establishment, but safety must be adequately established. This is especially true of different soil types and environments. In California's Central Valley, pendimethalin has been seen to occasionally cause injury in poppy plantings, which is in contrast with this study.
Table 4: Spring crop coverage (%) from plots treated with post-emergent herbicides one month after planting, which happened the prior October. Missing data from Phacelia and Lobularia at LB is due to crop loss from frost injury. |
|||||||
Crop coverage (%) |
|||||||
|
Corvallis |
Amity |
LB |
|
Corvallis |
Amity |
LB |
Hairy Vetch |
|
|
|
Gilia |
|
|
|
Untreated |
29 |
28 |
98 b |
Untreated |
0 |
8 |
54 b |
Mesotrione |
21 |
3 a |
0 a |
Mesotrione |
0 |
0 |
0 a |
Rimsulfuron |
18 |
1 a |
0 a |
Rimsulfuron |
0 |
4 |
78 b |
Quinclorac |
34 |
0 a |
28 a |
Quinclorac |
0 |
0 |
6 a |
Bentazon |
50 |
26 b |
94 b |
Bentazon |
0 |
7 |
47 b |
Phacelia |
|
|
|
Clarkia |
|
|
|
Untreated |
0 |
53 ab |
|
Untreated |
3 a |
0 |
83 b |
Mesotrione |
0 |
42 ab |
|
Mesotrione |
0 a |
0 |
34 b |
Rimsulfuron |
5 |
17 a |
|
Rimsulfuron |
4 ab |
0 |
55 b |
Quinclorac |
5 |
64 b |
|
Quinclorac |
15 b |
0 |
77 b |
Bentazon |
2 |
48 ab |
|
Bentazon |
6 ab |
0 |
0 a |
Poppy |
|
|
|
Lobularia |
|
|
|
Untreated |
2 |
11 |
2 |
Untreated |
0 |
0 |
|
Mesotrione |
3 |
11 |
0 |
Mesotrione |
0 |
0 |
|
Rimsulfuron |
6 |
0 |
0 |
Rimsulfuron |
0 |
0 |
|
Quinclorac |
2 |
5 |
3 |
Quinclorac |
0 |
0 |
|
Bentazon |
2 |
9 |
0 |
Bentazon |
0 |
0 |
|
Table 5: Spring crop coverage for pre-emergent herbicide treatments applied just after planting, which happened the prior October. Phacelia and Lobularia experienced winter kill at the LB location, so reported data is coverage from December for that location. |
||||||||
Crop coverage (%) |
||||||||
|
Corvallis |
Amity |
LB |
|
Corvallis |
Amity | LB | |
Hairy Vetch |
|
|
|
Gilia |
|
|
|
|
Nontreated |
29 |
28 ad |
98 b |
Nontreated |
0 |
8 a |
54 c |
|
Glyphosate |
23 |
46 bd |
|
Glyphosate |
0 |
47 b |
|
|
Indaziflam |
6 |
3 d |
79 b |
Indaziflam |
0 |
3 a |
36 bc |
|
Isoxaben |
11 |
17 ab |
83 b |
Isoxaben |
0 |
5 a |
31 ac |
|
Napropamide |
8 |
19 ab |
91 b |
Napropamide |
0 |
38 b |
56 c |
|
Flumioxazin |
5 |
36 bd |
90 b |
Flumioxazin |
0 |
18 a |
2 c |
|
Pendimethalin |
6 |
38 bd |
98 b |
Pendimethalin |
0 |
0 a |
13 ab |
|
Simazine |
34 |
55 d |
98 b |
Simazine |
0 |
44 b |
6 ab |
|
Mesotrione |
6 |
25 abc |
0 a |
Mesotrione |
0 |
3 a |
8 ab |
|
Phacelia |
|
|
|
Clarkia |
|
|
|
|
Nontreated |
0 a |
53 bc |
96 b |
Nontreated |
3 |
0 a |
83 b |
|
Glyphosate |
11 b |
92 c |
|
Glyphosate |
5 |
34 b |
|
|
Indaziflam |
0 a |
13 ab |
90 b |
Indaziflam |
0 |
0 a |
74 b |
|
Isoxaben |
0 a |
0 a |
82 b |
Isoxaben |
0 |
8 a |
88 b |
|
Napropamide |
2 a |
81 c |
98 b |
Napropamide |
0 |
25 b |
86 b |
|
Flumioxazin |
0 a |
30 ab |
57 ab |
Flumioxazin |
0 |
5 a |
20 a |
|
Pendimethalin |
0 a |
0 a |
15 a |
Pendimethalin |
0 |
2 a |
67 b |
|
Simazine |
0 a |
75 c |
56 ab |
Simazine |
0 |
30 b |
0 a |
|
Mesotrione |
2 a |
54 bc |
99 b |
Mesotrione |
0 | 0 a | 25 a | |
Poppy |
|
|
|
Lobularia |
|
|
|
|
Nontreated |
2 a |
11 |
2 a |
Nontreated |
0 |
0 a |
70 c |
|
Glyphosate |
30 b |
42 |
|
Glyphosate |
0 |
21 ab |
|
|
Indaziflam |
2 a |
8 |
8 a |
Indaziflam |
0 |
0 a |
16 ab |
|
Isoxaben |
2 a |
3 |
69 b |
Isoxaben |
0 |
0 a |
0 a |
|
Napropamide |
6 a |
14 |
0 a |
Napropamide |
0 |
47 c |
98 d |
|
Flumioxazin |
2 a |
31 |
63 bc |
Flumioxazin |
0 |
15 a |
34 b |
|
Pendimethalin |
2 a |
40 |
64 b |
Pendimethalin |
0 |
0 a |
0 a |
|
Simazine |
0 a |
46 |
28 ac |
Simazine |
0 |
44 bc |
5 a |
|
Mesotrione |
0 a |
7 |
8 a |
Mesotrione |
0 | 3 a | 3 a |
Figure 2: Crop coverage pictures from two months after planting the Lewis-Brown research farm show that the planted species (rows) tolerated several pre-emergent herbicides (columns). A black outline surrounds successful combinations seen in at least one of the other two trials. Combinations that were never seen to be successful again are surrounded by a red outline.
References:
Leponiemi, M., Freitak, D., Moreno-Torres, M. et al. (2023). Honeybees' foraging choices for nectar and pollen revealed by DNA metabarcoding. Sci Rep 13, 14753. https://doi.org/10.1038/s41598-023-42102-4
Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at the following link: http://websoilsurvey.sc.egov.usda.gov/.
- Author: Kathy Keatley Garvey
The United Nations designated May 20 as World Bee Day to raise awareness of the importance of pollinators, the threats they face and their contribution to sustainable development, according to its website.
It originated in 2018 when the government of Slovenia proposed that the United Nations declare May 20 as World Bee Day.
Why May 20? That was the day Anton Janša (1734-1773), a pioneer of modern apiculture, was born. "Janša came from a family of beekeepers in Slovenia, where beekeeping is an important agricultural activity with a long-standing tradition," relates Apimondia.
Today, however, let's pay tribute to the bumble bees. The late Robbin Thorp (1933-2019), UC Davis distinguished emeritus professor, UC Davis Department of Entomology and Nematology, used to point out there's only one bumble bee genus--Bombus--and that more than 250 species belong to this genus. California has 27 species of Bombus, according to Thorp in his 1983 published research, "Bumble Bees and Cuckoo Bumble Bees of California," written with colleagues Donald Horning Jr. and Lorry Dunning.
In his retirement, Thorp co-authored two books Bumble Bees of North America: An Identification Guide (Princeton University, 2014) and California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday, 2014).
Thorp, a member of the UC Davis entomology faculty for 30 years (1964-1994), continued his research, teaching and public service until his death in 2019 at age 85.
Franklin's bumble bee, Bombus franklini--a bee that he monitored for decades until his death in 2019--is now protected as an endangered species under the Endangered Species Act (ESA). It is feared extinct. Thorp, the last known person to see Franklin's bumble bee in its native habitat, spotted it in 2006 near Mt. Ashland. The bee inhabits--or did--a 13,300-square-mile area confined to five counties--Siskiyou and Trinity counties in California; and Jackson, Douglas and Josephine counties in Oregon. Its range may be the smallest range of any bumble bee species in North America, or even the world, he mused.
Today scientists are worried about the declining bumble bee population, a decline attributed to climate change, habitat loss, and pesticides. Bumble bees are especially known for their "buzz pollination" of such plants as tomatoes, peppers and cranberries. They help pollinate crops worth an estimated $3 billion in the United States alone.
"Due to threats including habitat loss, pesticide use and disease, sightings of the bee have declined by 89%, and it's disappeared completely from eight states. The decline of this once-common native bee is alarming and heartbreaking — and a harbinger of massive biodiversity loss across the country."--Center for Biological Diversity.
The dominant bumble bee species in California is the yellow-faced bumble bee, Bombus vosnesenskii. The Western bumble bee, B. occidentalis, used to be quite common. "It's one of four bumble bee species cleared by the state's Third Appellate District Court of Appeal for inclusion on California's endangered species list," according to a UC Riverside news story, published in July 2022.
Access the California Bumble Bee Atlas website to see how you can help. Meanwhile, how many species of bumble bees have you seen and photographed in California? Here are some of them.
- Author: Saoimanu Sope
UCCE specialist's research prevents water pollution, reduces water use
When interviewed to become a University of California Cooperative Extension specialist in environmental horticulture, Lorence “Loren” Oki was asked what kind of research he wanted to conduct.
In response, he showed the hiring committee a photo of a residential gutter. “Water is a big concern, and I found very little research on runoff from homes,” said Oki, explaining that studying residential runoff is what “started his career” with UC Agriculture and Natural Resources back in 2002.
Although he remains active supporting growers and advising industry leaders, Oki retired from UC ANR in July 2023. Before joining ANR, Oki worked as a researcher for UC Davis' Department of Environmental Horticulture studying greenhouse irrigation in 1994, bringing his total time with the University of California to 29 years.
Oki, professor emeritus of Cooperative Extension at UC Davis, led many research projects that advanced the green industry which includes landscapes, nurseries and floriculture.
“Loren is the epitome of a specialist,” said Darren Haver, UC ANR's Research and Extension Center system director, who has worked with Oki for more than 20 years on projects that have significantly improved urban water quality and water conservation efforts across California.
Research influences pesticide management
With a $3 million grant funding a statewide study, Oki and Haver set out to characterize runoff from residential sources over a five-year period. They determined the volume of irrigation runoff from residential land use, as well as the pollutants in the runoff.
Oki and Haver, co-principal investigators, along with researchers from UC Davis and UC Riverside, discovered that the degradation products of the insecticide fipronil – commonly found in runoff water – were more toxic than its parent compound. The study led to an investigation of human pathogens and pathogen indicators in residential runoff, the first of its kind.
Another contribution was the early detection of a new pesticide used for ant control, enabling strategies to be put in place to prevent it from reaching local streams and creeks. Oki and Haver's work also persuaded the California Department of Pesticide Regulation to change pesticide labels to minimize the chances of pesticides moving off target during irrigation and rain events.
These changes included preventing pesticide application before predicted rain and preventing irrigation after applications, keeping pesticides from impervious surfaces, and restricting applications on lawns and landscape beds within two feet of impervious surfaces and others.
Plant trials expand beyond California
Oki was also the principal investigator of the Climate-Ready Landscape Plants project, which may be the largest irrigation trial in the western U.S., and the UC Plant Landscape Irrigation Trials, the California component of that project. The UCPLIT trials originated in 2004 at UC Davis as a research project by Karrie Reid, retired UCCE environmental horticulture advisor for San Joaquin County, while she was pursuing her master's degree. In 2017, the irrigation trials were duplicated at the South Coast Research and Extension Center.
These projects evaluate landscape plants under varying irrigation levels to determine their optimal performance in regions requiring supplemental summer water. Throughout the trial, Oki identified many landscape plants, including rose cultivars, that remain aesthetically pleasing with little water.
Today, the trials have expanded beyond California as the Climate-Ready Landscape Plants Project at Oregon State University, University of Washington, University of Arizona and Utah State University.
Growing up in the nursery industry
In 2017, Oki obtained tenure, allowing him to expand his professional responsibilities to include production horticulture, specifically greenhouses and nurseries, an industry he was extremely familiar with. “I come from a nursery family,” Oki explained. “My grandfather started Oki Nursery in the early 1900s.”
During World War II, Oki's family was incarcerated in the Poston Relocation Center in Arizona and lost their homes and property. When they were released, they returned to the nursery industry to rebuild their lives. “After World War II, my father and uncle got more involved with my grandfather's work,” he said.
The Oki family played an instrumental role in technological development for nurseries in general. Oki Nursery, which was located in Sacramento, worked closely with IBM and was the first to use a computerized system in the industry.
Oki developed computerized scheduling for the bedding plants, poinsettias, chrysanthemums, bulbs and other crops. He developed a method to calculate the cost of any crop grown by the nursery at any point in the crop cycle and computerized greenhouse environmental and irrigation controls. This may not sound impressive now, but that was in the 1980s.
“My father was known for being progressive and he also knew everyone at UC Davis,” said Oki. “He wanted to work with anyone who had an interest in doing something good for nurseries.”
Inducted into Green Industry Hall of Fame
In the 1950s, Oki Nursery partnered with researchers from UC Davis' agricultural engineering program and developed the overhead sprinklers commonly used in nurseries today. Until the 1980s, Oki Nursery was the largest nursery in Northern California. Before it shut down in 1993, Oki worked in the family business as a greenhouse manager when runoff became a growing concern.
“I remember getting served with a notice by the Regional Water Quality Control Board stating that we needed to prevent runoff because it was polluted with nitrate fertilizer, which was common in the nursery industry,” Oki said.
One of those efforts focused on using controlled-release fertilizer instead of applying fertilizer via irrigation as a liquid feed. “What we learned is that if we converted nurseries to controlled-release fertilizer, we could reduce the nitrate runoff,” he said. While a member of the Oki Lab, Bruno Pitton earned his Ph.D. studying nursery hydrology and the fate of nitrogen fertilizers in container crop production adding to the information on runoff and nitrate management. Pitton is now the environmental horticulture advisor for Placer and Nevada counties.
In 2023, Oki was inducted into the Green Industry Hall of Fame, which recognizes individuals with a minimum of 20 years in the landscape, nursery or floriculture industry and who have made significant contributions to the field.
Having grown up in the industry, Oki said that his father taught him to never be afraid to try new things. “If you think you have an idea that might work, do the best you can to make it work. If it doesn't work out, then it doesn't work out. And that's OK,” he said.
Revitalizing space for greater impact
This mentality encouraged Oki whenever tackling new tasks, like rebranding the California Ornamental Research Federation, a space for education and collaboration, as UC Nursery and Floriculture Alliance.
In 2009, Oki and David Fujino, executive director of the California Center for Urban Horticulture, became co-directors of CORF, which catered to the cut flower industry. At that time, Oki and Fujino realized that nurseries generated much greater revenue in the state than cut flowers.
“It was a strategic decision to change CORF to UCNFA, which included floriculture and nurseries in the name,” Fujino said. Combined, nurseries and floriculture have consistently placed in the top five agricultural commodities in the state.
When reflecting on their partnership, Fujino said that working with Oki was a “natural fit.” “I couldn't have asked for a better partner, a better colleague and, ultimately, a better friend to have my back and work side by side,” he added.
Since UCNFA's launch, the two have worked to maintain the group's impact by hosting “Ask your Advisor” webinars to connect advisors to growers, as well as co-hosting large-scale events such as the annual conference for the International Plant Propagators' Society — an organization focused on greenhouse and nursery production education — for the Western Region, which Oki's father helped establish in the 1960s.
Encouraging a return to education
Gerry Spinelli, UC Cooperative Extension production horticulture advisor for San Diego County and member of UCNFA's administrative committee, described those who have learned from Oki as his sons and daughters. “When I meet someone that's learned from Loren or worked with him, that person instantly becomes my friend. That's the kind of effect Loren has on us,” Spinelli said.
Grant Johnson, UC Cooperative Extension urban agricultural technology advisor for Los Angeles and Orange counties, credits Oki for his master's degree in horticulture from UC Davis.
“Loren gave me a lot of direction as far as career choices and research interests. He instilled in me a dedication to life-long learning, just like he continues to do,” said Johnson. Before Oki became his professor, Johnson worked with Oki as a staff research associate at the South Coast Research and Extension Center in Irvine.
Another influential person in Oki's life is John Kabashima, emeritus environmental horticulture advisor for UCCE Orange and Los Angeles counties and fellow Green Hall of Fame inductee. Like Oki, Kabashima grew up in the nursery industry.
Oki, who earned a bachelor's degree in ornamental horticulture from Cal Poly San Luis Obispo and a master's degree in plant science from UC Riverside, decided to pursue a Ph.D. in ecology at UC Davis with Kabashima's encouragement.
While Oki was still working in his family's business, Kabashima said that Oki relied on UC ANR researchers for scientific information and felt like Oki wanted to be one of them. “I told him that he's a good nursery guy, but he's a better scientist,” said Kabashima. “His heart is in science.”
The two began working together as soon as Oki became a graduate student and have been colleagues and friends for nearly 40 years. “My favorite response from Loren whenever people ask him a question is, ‘It depends,'” Kabashima said. “It always leads to people opening up and giving more context. That's what Loren does, he gets you to think.”
/h3>- Author: Kathy Keatley Garvey
Those are some of the activities planned when the Bohart Museum of Entomology hosts an open house on managed bees and wild bees on Sunday, May 19.
The open house, free and family friendly, takes place from 1 to 4 p.m. in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus.
It's perfect timing for "World Bee Day," observed annually on May 20.
At the Sunday open house, UC Davis graduate student Richard Martinez of the lab of apiculturist Elina Lastro Niño, associate professor of Cooperative Extension, UC Davis Department of Entomology and Nematology, will staff the honey bee booth.
Martinez, enrolled in the master's graduate studies entomology program, says that the E.L, Niño Lab booth will display an observation hive and offer honey tasting from a variety of floral sources. He will be sharing recent projects aimed at improving honey bee health via dietary supplements. He also plans to showcase beekeeping suits and hive tools.
Among others scheduled to participate (as of 4 p.m. today) are:
- the laboratory of community ecologist Rachel Vannette, associate professor and chair of the UC Davis Department of Entomology. She will participate with lab members doctoral candidate Lexie Martin, doctoral student Dino Sbardellati, and junior specialist Leta Landucci. "At the Vannette Lab booth, you will be able to look into the life of a bee--both in terms of where they live and how they develop!" said Martin. "A live bumble bee nest and solitary bee nests will be available, so you can peer inside a bee's house! Additionally, there will be live bee larvae to observe under a microscope and interactive displays on the bee life cycle."
- Bohart Museum bee scientists Thomas Zavortink and Sandy Shanks
- Doctoral student Sofía Meléndez Cartagena of the Stacey Combes lab, Department of Neurobiology, Physiology and Behavior. She will focus on local bee diversity.
- Chancellor's Fellow Santiago Ramirez, associate professor, Department of Evolution and Ecology, who studies orchid bees
- Doctoral student Peter Coggan of the Ramirez lab. He studies the neurological and genetic basis of orchid bee courtship behavior and evolution.
- UC Davis distinguished professor emerita Lynn Kimsey, who retired as director of the Bohart Museum on Feb. 1, after 34 years as director. Kimsey, known as "the wasp woman," is a past president of the International Society of Hymenopterists. She studied orchid bees in Panama for her dissertation.
The Bohart Museum houses a global collection of eight million insects, plus a live petting zoo, and a gift shop. Professor Jason Bond directs the museum as of Feb. 1, succeeding Kimsey, who served 34 years. Bond is the Evert and Marion Schlinger Endowed Chair of the Department of Entomology and Nematology, and the associate dean, UC Davis College of Agricultural and Environmental Sciences. He also serves as president-elect of the American Arachnological Society.
For more information, access the website at https://bohart.ucdavis.edu or contact bmuseum@ucdavis.edu.
/span>- Author: Saoimanu Sope
UCCE specialist's research prevents water pollution, reduces water use
When interviewed to become a University of California Cooperative Extension specialist in environmental horticulture, Lorence “Loren” Oki was asked what kind of research he wanted to conduct.
In response, he showed the hiring committee a photo of a residential gutter. “Water is a big concern, and I found very little research on runoff from homes,” said Oki, explaining that studying residential runoff is what “started his career” with UC Agriculture and Natural Resources back in 2002.
Although he remains active supporting growers and advising industry leaders, Oki retired from UC ANR in July 2023. Before joining ANR, Oki worked as a researcher for UC Davis' Department of Environmental Horticulture studying greenhouse irrigation in 1994, bringing his total time with the University of California to 29 years.
Oki, professor emeritus of Cooperative Extension at UC Davis, led many research projects that advanced the green industry which includes landscapes, nurseries and floriculture.
“Loren is the epitome of a specialist,” said Darren Haver, UC ANR's Research and Extension Center system director, who has worked with Oki for more than 20 years on projects that have significantly improved urban water quality and water conservation efforts across California.
Research influences pesticide management statewide
With a $3 million grant funding a statewide study, Oki and Haver set out to characterize runoff from residential sources over a five-year period. They determined the volume of irrigation runoff from residential land use, as well as the pollutants in the runoff.
Oki and Haver, co-principal investigators, along with researchers from UC Davis and UC Riverside, discovered that the degradation products of the insecticide fipronil – commonly found in runoff water – were more toxic than its parent compound. The study led to an investigation of human pathogens and pathogen indicators in residential runoff, the first of its kind.
Another contribution was the early detection of a new pesticide used for ant control, enabling strategies to be put in place to prevent it from reaching local streams and creeks. Oki and Haver's work also persuaded the California Department of Pesticide Regulation to change pesticide labels to minimize the chances of pesticides moving off target during irrigation and rain events.
These changes included preventing pesticide application before predicted rain and preventing irrigation after applications, keeping pesticides from impervious surfaces, and restricting applications on lawns and landscape beds within two feet of impervious surfaces and others.
Plant trials expand beyond California
Oki was also the principal investigator of the Climate-Ready Landscape Plants project, which may be the largest irrigation trial in the western U.S., and the UC Plant Landscape Irrigation Trials, the California component of that project. The UCPLIT trials originated in 2004 at UC Davis as a research project by Karrie Reid, retired UCCE environmental horticulture advisor for San Joaquin County, while she was pursuing her master's degree. In 2017, the irrigation trials were duplicated at the South Coast Research and Extension Center.
These projects evaluate landscape plants under varying irrigation levels to determine their optimal performance in regions requiring supplemental summer water. Throughout the trial, Oki identified many landscape plants, including rose cultivars, that remain aesthetically pleasing with little water.
Today, the trials have expanded beyond California as the Climate-Ready Landscape Plants Project at Oregon State University, University of Washington, University of Arizona and Utah State University.
Growing up in the nursery industry
In 2017, Oki obtained tenure, allowing him to expand his professional responsibilities to include production horticulture, specifically greenhouses and nurseries, an industry he was extremely familiar with. “I come from a nursery family,” Oki explained. “My grandfather started Oki Nursery in the early 1900s.”
During World War II, Oki's family was incarcerated in the Poston Relocation Center in Arizona and lost their homes and property. When they were released, they returned to the nursery industry to rebuild their lives. “After World War II, my father and uncle got more involved with my grandfather's work,” he said.
The Oki family played an instrumental role in technological development for nurseries in general. Oki Nursery, which was located in Sacramento, worked closely with IBM and was the first to use a computerized system in the industry.
Oki developed computerized scheduling for the bedding plants, poinsettias, chrysanthemums, bulbs and other crops. He developed a method to calculate the cost of any crop grown by the nursery at any point in the crop cycle and computerized greenhouse environmental and irrigation controls. This may not sound impressive now, but that was in the 1980s.
“My father was known for being progressive and he also knew everyone at UC Davis,” said Oki. “He wanted to work with anyone who had an interest in doing something good for nurseries.”
Inducted into Green Industry Hall of Fame
In the 1950s, Oki Nursery partnered with researchers from UC Davis' agricultural engineering program and developed the overhead sprinklers commonly used in nurseries today. Until the 1980s, Oki Nursery was the largest nursery in Northern California. Before it shut down in 1993, Oki worked in the family business as a greenhouse manager when runoff became a growing concern.
“I remember getting served with a notice by the Regional Water Quality Control Board stating that we needed to prevent runoff because it was polluted with nitrate fertilizer, which was common in the nursery industry,” Oki said.
One of those efforts focused on using controlled-release fertilizer instead of applying fertilizer via irrigation as a liquid feed. “What we learned is that if we converted nurseries to controlled-release fertilizer, we could reduce the nitrate runoff,” he said. While a member of the Oki Lab, Bruno Pitton earned his Ph.D. studying nursery hydrology and the fate of nitrogen fertilizers in container crop production adding to the information on runoff and nitrate management. Pitton is now the environmental horticulture advisor for Placer and Nevada counties.
In 2023, Oki was inducted into the Green Industry Hall of Fame, which recognizes individuals with a minimum of 20 years in the landscape, nursery or floriculture industry and who have made significant contributions to the field.
Having grown up in the industry, Oki said that his father taught him to never be afraid to try new things. “If you think you have an idea that might work, do the best you can to make it work. If it doesn't work out, then it doesn't work out. And that's OK,” he said.
Revitalizing space for greater impact
This mentality encouraged Oki whenever tackling new tasks, like rebranding the California Ornamental Research Federation, a space for education and collaboration, as UC Nursery and Floriculture Alliance.
In 2009, Oki and David Fujino, executive director of the California Center for Urban Horticulture, became co-directors of CORF, which catered to the cut flower industry. At that time, Oki and Fujino realized that nurseries generated much greater revenue in the state than cut flowers.
“It was a strategic decision to change CORF to UCNFA, which included floriculture and nurseries in the name,” Fujino said. Combined, nurseries and floriculture have consistently placed in the top five agricultural commodities in the state.
When reflecting on their partnership, Fujino said that working with Oki was a “natural fit.” “I couldn't have asked for a better partner, a better colleague and, ultimately, a better friend to have my back and work side by side,” he added.
Since UCNFA's launch, the two have worked to maintain the group's impact by hosting “Ask your Advisor” webinars to connect advisors to growers, as well as co-hosting large-scale events such as the annual conference for the International Plant Propagators' Society — an organization focused on greenhouse and nursery production education — for the Western Region, which Oki's father helped establish in the 1960s.
Encouraging a return to education
Gerry Spinelli, UC Cooperative Extension production horticulture advisor for San Diego County and member of UCNFA's administrative committee, described those who have learned from Oki as his sons and daughters. “When I meet someone that's learned from Loren or worked with him, that person instantly becomes my friend. That's the kind of effect Loren has on us,” Spinelli said.
Grant Johnson, UC Cooperative Extension urban agricultural technology advisor for Los Angeles and Orange counties, credits Oki for his master's degree in horticulture from UC Davis.
“Loren gave me a lot of direction as far as career choices and research interests. He instilled in me a dedication to life-long learning, just like he continues to do,” said Johnson. Before Oki became his professor, Johnson worked with Oki as a staff research associate at the South Coast Research and Extension Center in Irvine.
Another influential person in Oki's life is John Kabashima, emeritus environmental horticulture advisor for UCCE Orange and Los Angeles counties and fellow Green Hall of Fame inductee. Like Oki, Kabashima grew up in the nursery industry.
Oki, who earned a bachelor's degree in ornamental horticulture from Cal Poly San Luis Obispo and a master's degree in plant science from UC Riverside, decided to pursue a Ph.D. in ecology at UC Davis with Kabashima's encouragement.
While Oki was still working in his family's business, Kabashima said that Oki relied on UC ANR researchers for scientific information and felt like Oki wanted to be one of them. “I told him that he's a good nursery guy, but he's a better scientist,” said Kabashima. “His heart is in science.”
The two began working together as soon as Oki became a graduate student and have been colleagues and friends for nearly 40 years. “My favorite response from Loren whenever people ask him a question is, ‘It depends,'” Kabashima said. “It always leads to people opening up and giving more context. That's what Loren does, he gets you to think.”
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