- (Focus Area) Pest Management
- Author: Jorge Antonio Angeles
- Posted by: Gale Perez
Silverleaf nightshade, Solanum Elaeagnifolium, is perennial weed that is native to South America, Mexico, American Southwest and Southern States. This herbaceous and woody summer weed belongs to Solanaceae just like other weeds such as black nightshade (Solanum nigrum), hairy nightshade (Solanum physalifolium) and horsenettle (Solanum carolinense). It can be found throughout California and in grows in desert and semi-arid areas. Silverleaf nightshade is often found growing in different cropping systems, rangeland, pastures, roadsides, and disturbed areas. Silverleaf nightshade is highly adaptable and can tolerate a wide range of soil and climatic conditions such as high temperatures, low rainfall, saline and drought conditions. The leaves and berries produced by silverleaf nightshade plants have glycoalkaloid compounds that can be toxic to livestock and humans if consumed (UC IPM) (Boyd 1982).
Life Cycle
Impacts
Silverleaf nightshade is becoming a problematic weed in some young pistachio orchards in Tulare, Kings and West Fresno. This perennial weed is mostly found in young orchards that are planted on west Fresno and Kings County by interstate 5 highway (Figure 3). In Tulare County, silverleaf nightshade is found pistachio orchards that were planted in unmanaged fallow land or in fields near roadsides where it's commonly found. One of the major impacts of silverleaf nightshade is that it competes with young pistachio orchard for resources such as water, light and nutrients. If left unmanaged, silverleaf nightshade can also interfere with irrigation operations and potentially reduce crop vigor in young pistachio trees (Figure 2). Since silverleaf nightshade can adapt to alkaline and saline soils, it will also outcompete many of the summer annual weeds and become the dominant weed in the population.
Management
Silverleaf nightshade can be a weed that is difficult to control with the available management methods in orchards. Tillage is not recommended as that is one of the ways that rhizomes can be spread across the orchard (Ensby 2011). Mechanical control methods such mowing can be an effective control method to prevent weeds from setting seed. Flail mowers are often used in orchards and vineyards to mow weeds in between tree rows. It is important to note that, new silverleaf nightshade shoots will potentially sprout from the root system after the tops are mowed (Stanton 2011). Even though mowing can be an effective weed control method during the growing season, most commercial mowers will miss the weeds that grow in between trees that directly compete with young trees. Hand weeding can be used to remove some of the weeds around the trees, but extra precaution needs to be taken. Mature silverleaf nightshade plants are covered in reddish prickles that can be harmful if weeds are handled with bare hands. Weeding tools such as shovels and hula hoes can damage surface drip hoses if the user is not careful.
Herbicides can be an effective weed management method to control silverleaf nightshade in different tree crops. There are a twelve pre-emergent and thirteen post-emergent herbicides with different sites of action that are registered for use in pistachios (Table 1). Pre-emergent herbicides are normally applied during the dormant season and most only control weeds before they germinate. Pendimethalin, rimsulfuron, mesotrione, flumioxazin, isoxaben, and flazasulfuron are herbicides that have great control over black and hairy nightshade. Isoxaben can suppress silverleaf nightshade, but cannot be used in pistachios that have not been established for at least three years. Pre-emergent herbicides will not control silverleaf nightshade that emerges from rhizomes in the summer. Post-emergent herbicides can be used to control silverleaf nightshade that emerges in the summer and early fall before harvest. Glyphosate, glufosinate, pyraflufen, and carfentrazone are post-emergent herbicides with different sites of action that can be used to control different weeds and can be used up to two weeks before harvest. 2, 4-D is another post-emergent herbicide that is registered for use in pistachios, but needs to be applied to trees that have been established for at least one year and has a pre-harvest interval of 60 days. Research work from other researchers has shown that glyphosate and 2, 4-D have excellent control of silverleaf nightshade (DiTomaso 2013) (Gitsopoulos 2017). Glyphosate is a systemic herbicide that can potentially kill the root system of silverleaf nightshade, when applied at the correct timing and rate. Since Silverleaf nightshade has extensive rhizome root systems, the root systems need to be killed to fully control this weed. In the summer months, a combination of mowing and the use of post-emergent herbicides can kill the aboveground tissues of silverleaf nightshade weeds and deplete the root bank in the soil (Heap 2018). Post-emergent herbicides need adjuvants such as nonionic surfactants, crop and seed oils, to increase their efficacy. Furthermore, always consult the herbicide labels on information regarding information on the required adjuvants, pre-harvest intervals, application rates and maximum applications per seasons.
The weed management tools to control silverleaf nightshade in pistachio orchards are limited. Developing and maintaining field records before planting is a great way to determine the history of a field before planting. Conducting weed surveys in the winter and spring can help determine what weed species are present in a field. Silverleaf nightshade populations can be reduced by mowing in between tree rows and applying herbicides to weeds present in between trees. These management practices need to be done before the weeds set seeds to contribute to reduce the seedbank. To avoid introducing silverleaf nightshade to other fields, it is important to sanitize tractor equipment and manage the weeds that grow on the field edges or near irrigation canals (. To have an effective silverleaf nightshade management program, a combination of herbicides with different modes of action are needed decrease the possibility of it developing herbicides resistance. Silverleaf nightshade is difficult to control because of its tolerance to many herbicides (Gitsopoulos 2017). During the summer months, it is best to use a combination of systemic and contact post-emergent herbicides to get higher levels of control for silverleaf nightshade. To enhance the efficacy and herbicide absorption, post-emergent herbicides require adjuvants such as methylated seed oils, non-ionic surfactants, crop-oil concentrates, and nitrogen-based fertilizers.
Cited Literature
Boyd, J.W. and Murray, D.S. 1982. Growth and development of silverleaf nightshade (Solanum elaeagnifolium). Weed Science 30, 238-43.
DiTomaso, J.M., G.B. Kyser et al. 2013. Weed Control in Natural Areas in the Western United States. Weed Research and Information Center, University of California. 544pp.
Ensbey R. 2011. Noxious and environmental weed control handbook – A guide to weed control in non-crop, aquatic and bushland situations. 6th ed. New South Wales: Department of Trade and Investment, Regional Infrastructure and Services.
Gitsopoulos, Thomas & Damalas, Christos & Georgoulas, Ioannis. 2017. Chemical options for the control of silverleaf nightshade (Solanum elaeagnifolium). Planta Daninha. 35. 10.1590/s0100-83582017350100064.
Heap, J. & Wu, H. 2018. Silverleaf Nightshade: Australian best practice management manual. Primary Industries and Regions SA & NSW Department of Primary Industries: Adelaide.
Roberts J., Florentine. 2022. Biology, distribution and management of the globally invasive weed Solanum elaeagnifolium Cav. (silverleaf nightshade): A global review of current and future management challenges. Weed Res. 2022;62:393–403. doi: 10.1111/wre.12556.
Stanton, R. & Wu, Hanwen & Lemerle, D. 2011. Root regenerative ability of silverleaf nightshade (Solanum elaeagnifolium Cav.) in the glasshouse. Plant Protection Quarterly. 26. 54-56.
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- Author: Lauren Fordyce
The multicolored Asian lady beetle, Harmonia axyridis, has a bad reputation. There is a common myth online that this lady beetle (ladybug) is invasive and aggressive, which can sometimes lead to people killing these beetles.
While this species of lady beetle was introduced to California from Asia in the 1990s to control aphid pests, it is not considered invasive. For an organism to be considered invasive it must be nonnative and cause harm to the environment, economy, or human health. Fortunately, the multicolored Asian lady beetle does not cause harm. Like many native lady beetle species, it feeds on pest insects like psyllids, scales, and especially aphids.
In the fall, multicolored Asian lady beetles can become a nuisance when they enter homes seeking shelter to overwinter. If you experience this problem, you can vacuum or sweep them up. Make sure windows, doors, and other openings to the outside are properly sealed to prevent the lady beetles and other insects from coming indoors. In the garden, adults may be attracted to ripening fruit when pest populations are low. In general, there is no need to control these lady beetles with pesticides.
Find out more about these predators and other beneficial insects in the UC IPM Natural Enemies Gallery.
- Author: Kathy Keatley Garvey
“I got two phone calls almost simultaneously on my two cell phones, so I thought this could not be a prank, but I am still in disbelief,” said Leal, a UC Davis distinguished professor in the Department of Molecular and Cellular Biology, and former professor and chair of the Department of Entomology (now Entomology and Nematology)
The caller: The National Academy of Sciences (NAS)
The message: You've been elected a member of the National Academy of Sciences, the highest honor a scientist can achieve.
"Members are elected to the National Academy of Sciences in recognition of their distinguished and continuing achievements in original research,” a spokesperson related. “Membership is a widely accepted mark of excellence in science and is considered one of the highest honors that a scientist can receive. Current NAS membership totals approximately 2,400 members and 500 international members, of which approximately 190 have received Nobel prizes."
“As they say, many deserving and few lucky ones," Leal commented. "Bruce Hammock told me many years ago that when he was elected to NAS, he looked around and saw many deserving colleagues. Now I understand that feeling very well. It is a tremendous and humbling honor. I hope an imposter syndrome does not kick in.”
Hammock, a UC Davis distinguished professor who holds a joint appointment with the Department of Entomology and Nematology, was elected a NAS member in 1999.
They are the only UC Davis entomologists who are NAS members.
Leal: World Leader in His Field
Leal, a native of Brazil and educated in Brazil, Japan and the United States, joined the UC Davis Department of Entomology in 2000. In 2013, he accepted a position with the Department of Molecular and Cellular Biology. "Walter is an internationally recognized entomologist and a world leader in his field for his groundbreaking and transformative research in insect olfaction and chemical ecology,” Hammock said. “He is truly a renaissance man. He chaired our entomology department from 2006 to 2008, and under his tenure, our department was ranked No. 1 in the country. I've long admired (1) his rigorous fundamental research programs supported by National Science Foundation, National Institutes of Health, and the U.S. Department of Food and Agriculture, and other agencies, (2) how he tackles and solves multiple challenging problems in insect olfaction and chemical ecology, (3) his grasp of how to organize and moderate highly successful worldwide research webinars (4) his generosity in helping other succeed and (4) his finely honed sense of humor."
Leal solves entomological problems spanning agriculture, human health, and welfare. He translates pheromone technology to agriculturists and serves as a principal investigator for the Pacific Southwest Regional Center of Excellence for Vector-Borne Diseases (affiliated with the Centers for Disease Control and Prevention). He holds more than 20 patents.
“Walter has been exceptionally conscientious, active, and generous in professional service at UC Davis,” Hammock pointed out. "In August of 2021, he achieved a ‘first' for international science communication when he organized and led the extraordinary virtual conference ‘Insect Olfaction and Taste in 24 Hours Around the Globe.' I especially applaud him for elucidating the mode of action of the insect repellent DEET, developed in 1946 and known as ‘the gold standard of repellents.' Its mode of action remained an enigma for six decades until Walter's discovery. In researching the neurons in mosquito antennae sensitive to DEET, he isolated the first DEET-sensitive odorant receptor, paving the way for the development of better repellents.”
May Berenbaum, professor and head, Department of Entomology, University of Illinois-Urbana-Champaign, National Medical of Science Laureate, NAS member, and editor of the Proceedings of the National Academy of Sciences, earlier wrote that “Dr. Leal is indisputably a world leader in the field of insect chemical ecology whose work over the course of his long and distinguished career has transformed basic knowledge of insect olfactory mechanisms and inspired innovative practical applications for sustainable management of insects of importance in agriculture and human health. He has contributed significantly to the current understanding of the structure and function of every component of olfaction, including receptors, binding proteins, and degrading enzymes, revising classic paradigms along the way. No textbook and no course on insect chemical communication could be considered complete without mentioning his landmark research achievements.”
'Just Like in a Honey Bee Colony'
Leal recently was named the 2024 recipient of the UC Davis Academic Senate's Distinguished Research Award, and will present a lecture on “Just Like in a Honey Bee Colony--It Takes a Team in the UC Davis Hive to Win an Award” at the Academic Senate's Faculty Distinguished Research Award Lecture Lunch on Tuesday, May 7 from noon to 1 p.m. in the UC Davis Conference Center.
Leal is the first UC Davis faculty member to receive the Academic Senate's trifecta of awards: outstanding teaching, public service, and research. Leal received the Academic Senate's 2020 Distinguished Teaching Award for Undergraduate Teaching, and the 2022 Distinguished Scholarly Public Service Award.
Among Leal's many honors: Fellow of the Entomological Society of America (2009), American Association for the Advancement of Science (2005), and the National Academy of Inventors (2019). He was elected a trustee of the Royal Entomological Society in February 2024.
Leal holds a Ph.D. in applied biochemistry from the University of Tsukuba, Japan, with subsequent postdoctoral training in entomology and chemical ecology at the National Institute of Sericultural and Entomological Science (NISES) and Cornell University, respectively. He was the first non-Japanese person to earn tenure at Japan's Ministry of Agriculture, Forestry, and Fisheries.
- Posted by: Gale Perez
Job #JPF01902
Location: Riverside, CA
APPLICATION WINDOW
Open date: April 17, 2024
Next review date: Wednesday, Jun 12, 2024 at 11:59pm (Pacific Time)
Apply by this date to ensure full consideration by the committee.
Final date: Sunday, Jun 30, 2024 at 11:59pm (Pacific Time)
Applications will continue to be accepted until this date, but those received after the review date will only be considered if the position has not yet been filled.
Job Description: https://aprecruit.ucr.edu/JPF01902
POSITION DESCRIPTION
The Department of Botany and Plant Sciences at the University of California Riverside invites applications for an Assistant Professor of Extension (Assistant Specialist in Cooperative Extension) in the area of weed management in agronomic crops. This is a fiscal year position available July 1, 2024 with an 80% Cooperative Extension and 20% Organized Research Appointment in the Agricultural Experiment Station (http://cnas.ucr.edu/about/aes/). The position will be housed at the University of California Riverside campus in Riverside, CA. The successful applicant will develop an internationally recognized, extramurally funded basic and applied research program on the management of non-aquatic weeds using chemical and non-chemical strategies that decrease weed competition, minimize environmental impacts from weed control practices, and reduce the economic costs of weed management. Preference will be given to candidates conducting research at the forefront of their field who have a strong working knowledge of weed management and control and a desire and ability to work with diverse clientele. Cooperative extension (CE) responsibilities include the development and implementation of educational programs on weed management in agronomic crops, which may include extension publications, newsletters, web pages, blogs, field days, participation in CE Advisor meetings, organizing workshops, and contributing to the University of California Agriculture and Natural Resources (UC ANR) workgroups and teams.
The current base pay range for the Assistant Professor of Extension position is $84,100 to $110,100 and the Agronomist/ Organized Research position is $86,500 to $112,800. Additional off-scale to be commensurate with market value, qualifications and experiences.
Required qualifications for this position that must be met by the date of application include: a Ph.D. in Weed Science, Agronomy, Plant Sciences or a related discipline, demonstrated experience in applied research, and excellent communication and interpersonal skills.
Preferred qualifications for this position include: Postdoctoral experience, experience in research and outreach with demonstrated productivity in publishing in journals related to weed management, and a track record of success in obtaining extramural funding.
Advancement through the Professorial ranks at the University of California is through a series of structured, merit-based evaluations, occurring every 2-3 years, each of which includes substantial peer input.
To apply: submit the following to https://aprecruit.ucr.edu/apply/JPF01902.
- Cover Letter – short cover letter describing background and interests
- Curriculum Vitae
- Statement of Teaching and Mentoring - This statement should be a concise description of the applicant's teaching and mentoring philosophy and include past experience and future teaching and mentoring plans (2-page maximum)
- Statement of Research interests and goals (3-page maximum)
- Statement of Extension interests and philosophy (2-page maximum)
- Statement of Past and/or Planned Future Contributions to Advancing Diversity and Inclusive Excellence (2-page maximum)
- 3 Letters of Reference – At time of submission, applicants should provide contact information and request letters of recommendation from 3 referees to be submitted through AP Recruit, Letters will need to be submitted to AP recruit from the letter writers by June 12, 2024.
- Up to 3 select reprints of publications or manuscripts in press (optional)
Review of applications will commence on June 12, 2024, and proceed until position is filled. For full consideration, applicants should submit their complete applications prior to the above date.
For the FULL JOB DESCRIPTION: https://aprecruit.ucr.edu/JPF01902
For more information about this position, please contact Dr. Milt McGiffen, Chair of the Search Committee, Department of Botany and Plant Sciences, at milt@ucr.edu. For questions on application procedures and requirements, please contact Mrs. Naudia Samuels Johnson, Academic Personnel, at naudia.samuelsjohnson@ucr.edu.
- Posted by: Gale Perez
Mark your calendar...
Diagnosing Herbicide Symptoms 2024 link
https://wric.ucdavis.edu/events/diagnosing_herbicide_symptoms_2024.html
Weed Day 2024 link
https://wric.ucdavis.edu/events/weed_day_2024.html