Why are wine bottles tall and narrow? That distinctive shape contributes to the happy marriage between cork and a bottle made tall enough to lie on its side so the wine can “breathe” through the cork as it matures. Lying on its side while stored in cool, dry cellars ensures that the liquid within the bottle will marinate the cork end just enough to keep it from drying out and crumbling.
What do wine, wax, and wrinkles have to do with local trees? In 1904, a cork oak grove was planted in Lower Bidwell Park near the Nature Center on East 8th Street. The grove was located within a 29-acre tract of land that John Bidwell donated in 1888 to the newly created State Board of Forestry for use as a woody plant nursery and demonstration plantation.
Cuttings and young plants were collected from all over the globe for the project, including species of willow, mulberry, linden, maple, oak, catalpa, pine, and eucalyptus. The ensuing planting spree in the 1890s included Sequoia gigantica, a tract of Italian cypress (these trees gave rise to the name “Cedar” Grove), and a large plot of Scots pine. Of those late-19th century conifer plantings, only the cypress remain: the Sequoia were decimated by a freak freeze in 1932, and bark beetles took all but a few of the pines.
The species can reach about 66 feet in height, but is usually smaller than that in its native habitat. There are two notable exceptions: In Portugal, the Sobreiro Monumental (Monumental Cork Oak), is 234 years old and 52 feet tall, with a trunk so large in circumference that it takes up to five people with outstretched arms to encircle it. It is listed as a National Monument, and cited in the Guinness Book of Records as the largest and oldest cork oak in the world. Closer to home, a Quercus suber in Napa is registered as a California Big Tree. It is 89 feet tall, with a trunk circumference of 20 feet, and a crown spread of 81 feet.
The acorns of the cork oak have a distinctive fringed cap, smooth chestnut skin, and characteristic green mark at the bottom, and the tree's shiny, deep green, loosely-lobed leaves are attractive. But its bark is the cork oak's claim to fame. Almost ghostly pale in color, the bark is deeply furrowed and springy, and provides an ecologically sustainable cash crop. The thick, insulating bark also makes it possible for the tree to survive fires, after which it regrows branches to fill out the canopy.
Modern uses aside, the method of harvesting the bark from the cork oak dates back to the Middle Ages, using an axe that has barely changed in all that time. Virgin (or “male”) cork is cut for the first time from trees about 25 years old. After that, the bark is harvested every 9 to 12 years. Trees can live over 200 years, and one harvest of bark from a single tree can produce enough to cork 4,000 bottles.
In the harvesting process, the bark is peeled from the tree by hand, using only an axe to strip the bark from around the tree. Absolutely no machinery is employed. It can take up to five people to harvest the bark of each tree. Because expertise and finesse is required to peel off the bark without damaging the trunk's cambium layer, harvesters train for about 8 years.
Our cork oaks in Lower Bidwell park were also harvested periodically; scars from a stripping performed in 1940 and again more recently are visible even now.
In addition to providing cork bark, cork oak groves in Portugal and Spain support another form of agriculture: their acorns provide sustenance to sheep, cattle, and especially hogs. A superior type of ham with a distinctive sought-after flavor is obtained from the Iberian pigs that feed on the fallen acorns.
Our local cork grove in Lower Bidwell Park provides a window into the past by hearkening back to the ancient farming traditions of the Mediterranean countries, and is a living legacy to John Bidwell's quest to, as local naturalist Rex Burress elegantly stated, grow plants “far from their native origins but brought together to mingle in a new habitat.” Best of all, in my opinion, is our cork oak grove's genetic bond to those trees that make a crucial contribution to good wine.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
Increasing participation in school meal programs can improve dietary quality and reduce nutrition insecurity. School food service directors have indicated an urgent need for marketing materials encouraging school meal participation. Nutrition Policy Institute will partner with Anna Grummon of Stanford University to develop and evaluate a marketing campaign to increase school meal participation. The evaluation will help to determine the school meal messaging that most resonates with parents. The two-year project, “Developing and evaluating a marketing campaign to increase school-meal participation to improve children's dietary quality and reduce food insecurity,” was funded by the Robert Wood Johnson Foundation's Healthy Eating Research program. The project started in November 2023 and includes NPI's Christina Hecht, Ken Hecht and Reka Vasicsek.
- Editor: Barbra Braaten
- Author: Jeanette Warnett
UC Master Gardeners across the state are on a scouting mission for the California Department of Food and Agriculture (CDFA), combing their communities and the local countryside to find the undesirable but common tree-of-heaven.
In contrast to its angelic name, tree-of-heaven is a noxious invasive plant that was introduced during the Gold Rush by Chinese miners who valued its medicinal properties. It is also the preferred host plant for two damaging exotic pests, the brown marmorated stink bug, already found in parts of California, and the spotted lanternfly, a leafhopper from China that officials want to keep out.
Spotted lanternflies were first detected in the U.S. in 2014 in Pennsylvania. They have since been spreading and are already found in 17 states, as far west as Illinois. Spotted lanternfly poses a significant threat to California agriculture and its natural areas, so CDFA is being proactive, organizing an effort to reduce the number of the pest's favorite host plant, tree-of-heaven.
Tree-of-heaven is found in 39 California counties, including Fresno County. It is a deciduous tree that can reach 75 feet in height with a 12-inch diameter near the base. It has smooth bark that resembles cantaloupe rind and compound leaves that contain dozens of leaflets. The tree tolerates unfavorable growing conditions on every type of topography in California below the 7,000-foot elevation. It is not an easy tree to eradicate. When cut down, it resprouts readily, creating even more trees in dense stands.
“CDFA has funding for elimination of tree-of-heaven,” said Missy Gable, director of the UC Master Gardener Statewide Program. “They need to know where the trees are located so funds can be allocated to local agencies for removal. With UC Master Gardeners' extensive training and statewide reach, they are uniquely equipped to support the project.”
More than 6,000 volunteers across the state are trained and certified UC Master Gardeners. They are dedicated to educating the public on sustainable gardening and being involved in environmental stewardship in their communities. About 300 Master Gardener volunteers have been trained to identify tree-of-heaven by assessing the bark, leaves, flowers and seeds. Using a simple online scouting tool, they will record the locations, number of trees in the stand, and the approximate diameter of the largest tree at breast height. The tool generates a map that can be used by researchers, CDFA and local public works officials to prioritize trees for removal.
If you would like more information on joining the UC Master Gardener scouting project you can watch the informational webinar here.
- Author: Pershang Hosseini
- Author: Tong Zhen
- Author: Matthew Fatino
- Author: Brad Hanson
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Broomrapes (Orobanche and Phelipanche spp.) are obligate plant parasites with a broad range of agricultural crop hosts. In non-parasitic plant species, seeds generally initiate germination when exposed to favorable conditions of temperature, humidity, oxygen, and, occasionally, light. However, for obligate parasitic plants like broomrapes, a chemical signal from the host plant is essential. Germination of broomrape can only occur under appropriate soil conditions and when the seed receives a strigolactone chemical signal released from the roots of a suitable host. Strigolactones (SLs) are carotenoid-derived hormones that play a crucial role in various aspects of plant growth and development. Fertilizers can regulate the production of these plant hormones (Xie et al. 2010).
Fertilization can improve soil conditions and lead to reduced initiation of broomrape parasitism (Fernández-Aparicio et al. 2016). Studies have shown that heavy infestations of crenate broomrape (Orobanche crenata Forsk.) on faba beans are linked to lower soil fertility (Trabelsi et al. 2017), and parasitism of Egyptian broomrape on tomato occurs more frequently in low-nutrient conditions (Jain and Foy 1992). The application of fertilizers has been reported to suppress the occurrence of other parasitic plants such as Striga (Jamil et al. 2011) and Egyptian broomrape (Phelipanche aegyptiaca) (Jain and Foy 1992). Fertilizers can reduce parasitism and enhance crop tolerance both directly, through toxic effects, and indirectly by improving soil fertility and plant health.
Direct toxic effect of fertilizers
Nutrient management can enhance both resistance and tolerance to broomrape parasitism in crops at the pre-attachment and post-establishment stages. Increasing the levels of nitrogen (N) and phosphorus (P) in the soil through fertilizer application can reduce the germination and subsequent infestation rates of parasitic weeds (Jamil et al. 2011). Ammonium nitrate combined with potassium phosphate or the use of ammonium phosphate alone proved to be effective in reducing parasitism and promoting the growth of tomato plants compared to potassium sulfate (Jain and Foy 1992). The direct inhibitory effects of nutrients on broomrape seeds can occur during the preconditioning, germination, and seedling elongation stages. Preconditioning Egyptian broomrape seeds in the presence ofammonium salts, such as ammonium sulfate or urea, significantly inhibited their germination; in contrast, nitrate did not have the same inhibitory effect (Jain and Foy 1992). Increasing nitrogen rate (ammonium nitrate) decreased seed germination and radicle length of branched broomrape (Irmaileh 1994). Another experiment showed that nitrogen in the ammonium form resulted in greater inhibition than nitrate, and the inhibition mechanism was actually a reduction in radicle elongation rather than inhibition of germination (Westwood and Foy. 1999).
Down-regulating of Strigolactones (SLs)
Fertilization can protect crops from parasitism by downregulating the synthesis and exudation of strigolactones, which are the most potent germination-inducing factors for root parasites (Fernández-Aparicio et al. 2016). Plants release SLs in different situations, including the establishment of symbiotic relationships between plants and certain soil microorganisms (Besserer et al. 2006; Kapulnik and Koltai 2014) and during stress response (Kapulnik and Koltai 2014). It is likely that plants produce strigolactones as a "cry for help," which broomrape exploits to its advantage. The availability of nutrients, particularly nitrogen, can decrease plant stress and subsequently downregulate the production of strigolactones. Effects of N, P, and K deficiencies on SL production showed that both N and P deficiencies enhanced SL exudation in resistant genotypes of faba bean (Trabelsi et al. 2017) and red clover (Yoneyama et al. 2012), while K deficiency had no effect (Trabelsi et al. 2017). A similar positive effect of low phosphate levels on SL production was also observed in tomato (López-Ráez et al. 2008).
In summary, effective nutrient management is a vital strategy in reducing broomrape parasitism and enhancing crop tolerance. By manipulating soil fertility and nutrient availability, it is possible to directly inhibit broomrape development and indirectly protect crops by downregulating strigolactone production. Appropriate fertilization and other stress-reducing management practices can reduce broomrape parasitism.
In addition to the indirect effects on broomrape, researchers in the Hanson lab are investigating the direct toxic effects of various fertilizers on broomrape seeds during three stages: preconditioning, germination, and post-germination (Figure 1). In future studies, we aim to explore the indirect effects of fertilization on broomrape parasitism, focusing on how nutrient management can influence the production of strigolactones and other related mechanisms. The ultimate goal of this work is to determine if manipulating fertilizer form, timing, or rates could directly inhibit branched broomrape and maximize tomato resilience to broomrape parasitism as part of an integrated management strategy.
a | b | c |
Figure 1: Branched broomrape seeds in different treatment conditions:
a) Germination (elongated radicle) observed in the control group.
b) No germination was observed when ammonium phosphate was applied at the germination stage.
c) Elongated radicle changed color when ammonium phosphate was applied post-germination.
References
Besserer, A., Puech-Pagès, V., Kiefer, P., Gomez-Roldan, V., Jauneau, A., Roy, S., ... & Séjalon-Delmas, N. (2006). Strigolactones stimulate arbuscular mycorrhizal fungi by activating mitochondria. PLoS Biology, 4(7), e226.
Fernández-Aparicio, M., Reboud, X., & Gibot-Leclerc, S. (2016). Broomrape weeds. Underground mechanisms of parasitism and associated strategies for their control: a review. Frontiers in Plant Science, 7, 171714.
Irmaileh, B. A. (1994). Nitrogen reduces branched broomrape (Orobanche ramosa) seed germination. Weed Science, 42(1), 57-60.
Jain, R., & Foy, C. L. (1992). Nutrient effects on parasitism and germination of Egyptian broomrape (Orobanche aegyptiaca). Weed Technology, 6(2), 269-275.
Jamil, M., Charnikhova, T., Cardoso, C., Jamil, T., Ueno, K., Verstappen, F., ... & Bouwmeester, H. J. (2011). Quantification of the relationship between strigolactones and Striga hermonthica infection in rice under varying levels of nitrogen and phosphorus. Weed Research, 51(4), 373-385.
Kapulnik, Y., & Koltai, H. (2014). Strigolactone involvement in root development, response to abiotic stress, and interactions with the biotic soil environment. Plant Physiology, 166(2), 560-569.
Trabelsi, I., Yoneyama, K., Abbes, Z., Amri, M., Xie, X., Kisugi, T., ... & Kharrat, M. (2017). Characterization of strigolactones produced by Orobanche foetida and Orobanche crenata resistant faba bean (Vicia faba L.) genotypes and effects of phosphorous, nitrogen, and potassium deficiencies on strigolactone production. South African Journal of Botany, 108, 15-22.
Westwood, J. H., & Foy, C. L. (1999). Influence of nitrogen on germination and early development of broomrape (Orobanche spp.). Weed Science, 47(1), 2-7.
Xie, X., Yoneyama, K., & Yoneyama, K. (2010). The strigolactone story. Annual Review of Phytopathology, 48, 93-117.
Yoneyama, K., Xie, X., Kim, H. I., Kisugi, T., Nomura, T., Sekimoto, H., ... & Yoneyama, K. (2012). How do nitrogen and phosphorus deficiencies affect strigolactone production and exudation?. Planta, 235, 1197-1207.
/table>- Author: Saoimanu Sope
Cerca de 200 residentes han sido capacitados en los últimos siete años como parte del programa Administradores del Medio Ambiente de UC
Durante uno de sus días más oscuros, Tammah Watts estaba parada frente al sink de su cocina para llenar una jarra con agua. Al otro lado de la ventana, la residente de San Marcos vio un aleteo a la distancia. Luego vio salir del árbol un pequeño pájaro amarillo y sus ojos se llenaron de admiración.
Observar a los pájaros desde la ventana de su cocina se convirtió en un escape para Watts mientras se recuperaba en su casa de una cirugía. Allí fue donde encontró una conexión más allá del interior de su casa.
“Empecé a notar otros pájaros que siempre estaban allí. El jardín no había cambiado, pero mi mente y mi perspectiva sí”, expresó Watts.
Ansiosa por aprender más y exponer a otros sobre su nuevo pasatiempo y su poder de sanación, Watts se unió al programa de University of California Environmental Stewards (Administradores del Medio Ambiente de la Universidad de California), un programa estatal bajo la División de Agricultura y Recursos Naturales de UC, con la idea de convertirse en naturalista certificada de California.
El programa ofrece dos cursos de certificación sobre educación del medio ambiente: el curso de naturalista de California, el cual introduce a las personas a las maravillas de la ecología única de California e involucra al público en el estudio y administración de las comunidades naturales del estado.
Una de las muchas fortalezas del programa es que permite a las personas de diferentes antecedentes encontrar intereses comunes en la naturaleza aun cuando las razones por las que se interesaron varíen, manifestó Eliot Freutel, especialista en educación comunitaria para el UC Environmental Stewards Program in Southern California (Programa de Administradores del Medio Ambiente de UC en el Sur de California). “Nuestros colaboradores que nos ayudan a administrar el curso son organizaciones que ya tienen acceso al público y ofrecen educación científica de manera informal, como los museos de historia natural o sociedades Audubon”, agregó Freutel.
Damos la bienvenida a una nueva cohorte de administradores del medio ambiente
A principios de marzo, el más antiguo curso de Naturalista de California en el condado de San Diego graduó a 25 nuevos miembros bajo la instrucción de Karen Merrill y Paige DeCino, siendo Watts una de ellos. Durante siete años, Merrill y DeCino han fungido como co instructoras del Centro de Naturaleza Buena Vista Audubon en Oceanside y graduado a 166 miembros antes de su clase más reciente y final.
En su transición a la jubilación, DeCino y Merrill reflexionaron sobre sus siete años de servicio y están orgullosas de ver las caras de más jóvenes y mayor diversidad unirse al programa Naturalistas de California. Tucker Shelton, quien junto con su madre se graduó recientemente, se encuentra entre los pocos jóvenes que se han unido al programa en los últimos años. El amor por la naturaleza se inició cuando Shelton descubrió marismas cuando apenas tenía 14 años. Shelton desea inspirar a una generación de jóvenes con su pasión y cariño por la naturaleza.
“Cuando estás joven y tu cerebro continúa desarrollándose, eres la persona más interesada en cosas nuevas. Si encuentras una pasión a una edad temprana, lo más probable es que crezcas con ella siendo parte de tu vida”, dijo Tucker, agregando que el proyecto final de su carrera se enfoca en un ensayo sobre los murciélagos de grandes orejas de Townsend que se encuentran en peligro de extinción y usa el arte de los sellos para crear consciencia. Su arte se mostrará y venderá en una próxima exhibición y todo lo recaudado será donado a Volcan Mountain Wilderness Preserveen Julian.
Hannah Márquez, otra graduada reciente que nació y creció en San Diego, valora su diversidad cultural y cree que la conexión entre el público y la naturaleza empieza con el lenguaje. Mientras trabaja para establecer una biblioteca actualizada sobre plantas nativas en el Parque Natural Tecolote Canyon y el Centro de Naturaleza en Mission Valley, Márquez proporciona información y recursos importantes en inglés y español.
“Muchas personas no se sienten cómodas usando la tecnología y depender del traductor Google Translate no va evitarlo”, indicó Márquez, agregando que el inglés limitado de sus padres inspiró este proyecto.
Márquez espera hacer que más gente se interese en cultivar plantas nativas en su patio trasero y cree que el acceso a la información es el primer paso para hacerlo.
“Ha sido muy gratificante para nosotros”, señaló Merrill. “Típicamente, nuestros estudiantes ya participan en la comunidad, pero para aquellos que no, es sorprendente verlos convertirse en parte de la misma y participar en un modo que no lo han hecho antes”.
DeCino estuvo de acuerdo diciendo que realmente espera encontrar nuevos instructores para mantener vivo el impulso de Naturalistas de California en el condado de San Diego. “Aun cuando nos vamos a jubilar, seguiremos estando aquí y allá, para nosotras es importante pasar la antorcha”, manifestó DeCino.
El futuro de Naturalistas de California en el condado de San Diego
¿Se preguntara, que sigue en el condado de San Diego?
“Definitivamente queremos expandirnos en el área. Pero en este momento, estamos en busca de ex alumnos interesados en hacerse cargo del programa que se realiza en el Centro de Naturaleza Buena Vista”, expresó Freutel. “También espero conseguir más colaboradores en el condado de San Diego para ofrecer el curso en varios lugares, no solo en North County, lo cual puede llevar a problemas sobre accesibilidad”.
Al igual que otros estudiantes, Márquez viajó una hora en cada sentido para participar en el programa UC Environmental Stewards program. “Es un curso que vale la pena, que ayuda a las personas a tener un impacto positivo en su propia comunidad”, dijo Freutel.
Para Watts, ayudar a gente a sanar y conectar al mundo a su alrededor – una experiencia de la que su libro, una guía para la poderosa sanación que ofrece la observación de pájaros, trata – es una prioridad. “No se trata solo de observar a los pájaros”, señaló. “Se trata de darnos cuenta del árbol en el que los pájaros viven y el suelo en el que crecen”.
Durante una caminata de un grupo de niños por la naturaleza que encabezó Watts, notó dos juegos de huellas en la tierra. Inmediatamente, pudo diferenciar uno del otro. “Uno pertenecía a un mapache y el otro a un venado”, dijo Watts. “Estaba muy emocionada de poder señalar la diferencia y les prometo que no lo sabía antes de tomar el curso CalNat”.
Para información sobre cómo puede ser parte del programa UC Environmental Stewards y convertirse en un naturalista de California o administrador del clima, visite: https://calnat.ucanr.edu/Take_a_class/