KC Whitsett joined the Nutrition Policy Institute at the University of California, Agriculture and Natural Resources on March 25, 2024, as a project policy analyst. Originally from Virginia, KC earned a BS in Kinesiology and Health Sciences from the College of William & Mary. KC also holds a Master of Public Health from UC Berkeley, with an interdisciplinary concentration on research and evaluation methods for food access and nutrition programs. Her previous professional experiences include program and grant management and community health education. She has expertise in the evaluation of physical activity and food access programs—healthy corner store initiatives, mobile markets, SNAP incentives—and farmworkers' access to health care services. In her role at NPI, KC will support qualitative data collection and analysis for projects related to school meals, the Child and Adult Care Food Program and the Special Supplemental Nutrition Program for Women, Infants and Children—commonly known as WIC.
- Author: Ben Faber
With all the rain last year, even extending into August and now with the rains since December there is a lot of natural ground cover growing, When it gets out of hand, we call it weedy. It might still serve the purpose of protecting the ground from erosion, but it can become an impenetrable mess and if allowed to go into summer, a major fire hazard. In the case of some young orchard, the malva and mustard is bigger than the trees themselves. Getting control of them before they get woody and go to seed is easier earlier than later. So it's time to do something about them if you haven't done so already.
A common practice on flat ground is to mow the middles and then weed whack/whip the tree row up to and around the tree trunk. In the case of trees that have their canopies down to the ground or near the ground or that have created a thick leaf mulch, there's not usually much weedy growth near the trunk. Then weed whacking around the canopy is not much of a problem. If on a slope like most avocados, it's a big, expensive, laborious, hot, sweaty, arduous process of weed whacking. Just waiting long enough for the leaf mulch to create a barrier to weed growth and for the canopies to grow out to rob the sun from the surface undergrowth.
In young trees without a large canopy, it can be a really difficult process of getting those weeds near the trunk. Care must be taken to avoid damage to the trunk. In a couple of recent examples, weed whacking got right up and on the trunks and significant damage was done to the trees. When a wound occurs in any tree, a process kicks in to generate tissue to cover the wound, much like what happens with humans and wound cuts. There's a scar left, but it heals over. If the wound is too large, many trees cant cover the woody tissue fast enough. The wood beneath the cambium ( the green tissue below the bark) is prone to fungal infection and eventually the fungus eats away at the interior of the tree. If the wound is large enough and girdles the tree, all the nutrients from the leaves feeding the roots is cut off. The photosynthate sugars that keep the roots functioning, and the roots stop doing what roots do. This is absolutely true is citrus and most other orchard tree crops. But not avocado.
When making a cross section of most trees, it's possible to see the growth rings – the growth increments that appear each year. The tree starts and stops growth each year and it's possible to clearly identified in what year there was more or less growth. In long lived trees like redwood, it's possible to identify years when certain events happened – the year of Lincoln's Gettysburg Address, for example. This growth habit is called ring porous.
In the case of avocado, it has a growth habit called diffuse porous. There is growth throughout the year and the rings are nor clearly delineated, if at all. It's because of this possible active growth occurring, that the avocado can often cover over damage that is quite extensive. After a fire, given time, mature avocado trees can summon up energy to recover to a great extent. It's not so true of young trees, however. Avocados still have a greater regenerative capacity than a lemon tree, and if the damage is to just one side of the tree, there's a very good chance of recovery.
But these young tree are severely impaired. They do have a chance of recovery, but the damage is extensive and the trunk is fully girdled. Only time will tell if they do recover. If the tree were only a year old, it would be a good idea to pull them and start over. But a number of these trees are three years old and have had a lot of investment in them besides their initial nursery cost – pruning, weeding, irrigation, fertilization, etc. It is heart breaking to see damage like this after so much attention has been paid to them.
And the best thing is to let the tree recover on its own. Use of pruning paint actually impairs tissue regeneration. The grower asked if a kaolin protectant like Surround might be used to provide some sun protection. Since that breathes, it might be a good idea. It might also be a good idea to apply some trunk wraps. These were taken off in order to prevent earwig and snail harbor which can cause significant damage to young trees. But they also provide protection from overly aggressive weed whackers. It is always a compromise when making these decisions.
- Author: Bradley Hanson
Several of us are part of a multi-state project on electrical weed control in organic blueberry and orchard crops. Tong Zhen is the lead grad student researcher on the UC Davis part of the project and we are working closely with our counterparts at Oregon State University (Marcelo Moretti and team) and Cornell University (Lynn Sosnoskie and team).
Tong wrote about our "first impressions" of the Zasso electrical weed control unit in 2022 and we included a demo of the equipment last year at the 2023 UC Weed Day. Tong's projects are just getting rolling for 2024 in blueberry, almond, and a new grower-led project with winegrape (more to come on those projects!).
Today, Luisa, the Oregon State University grad student on the project just posted a nice YouTube video of her electrical weed control research in organic blueberry in the Willamette Valley of Oregon. It's a nice walk-through of the research and has some good footage of the equipment in action. Here's the link to Marcelo and Luisa's video if you're interested: https://youtu.be/a_HHKVHeMjw?si=IKifjYX9M_ECTKrz
This research is funded by the National Institute of Food and Agriculture - Organic Research and Extension Initiative.
- Author: Diana Cervantes
Los campos de San Bernardino y Riverside están en alerta. La mosca oriental de la fruta (OFF, por sus siglas en inglés), ha desencadenado una cuarentena que obliga a los productores a tomar medidas estrictas para proteger los cultivos cítricos. En un esfuerzo por contener esta amenaza, se están implementando programas de tratamiento supervisados y restricciones de exportación, destacando la gravedad de la situación en la región.
Nawal Sharma del Departamento de Alimentos y Agricultura de California (CDFA, por sus siglas en inglés), destaca la importancia de estas medidas en un radio de 112 millas alrededor de Redlands.
Esto significa que los productores en el área de cuarentena no pueden vender ni transferir productos fuera de su propiedad sin un acuerdo de cumplimiento. El acuerdo requiere que los productores cumplan con un programa específico de tratamientos bajo la supervisión de agentes estatales o del condado.
La cuarentena no permite la exportación internacional de cítricos frescos provenientes de esta área, a menos que los cítricos obedezcan con los requisitos de certificación de exportación existentes para los artículos reglamentados provenientes de las áreas bajo cuarentena por la presencia de OFF.
En días pasados los campos de cítricos de la Universidad de Riverside se convirtieron en el centro de un importante evento para los agricultores y profesionales de la industria, una jornada de campo dedicada exclusivamente a este sector.
Durante la reunión, expertos en la materia dirigieron su atención hacia temas vitales que afectan a la industria, centrándose especialmente en las medidas de cuarentena relacionadas con OFF.
OFF es una plaga invasora originaria del sudeste asiático, y actualmente representa una amenaza directa para más de 230 variedades de cítricos, frutas, nueces y frutos rojos.
De acuerdo con el Departamento de Alimentos y Agricultura de California (CDFA, por sus siglas en inglés), una invasión de este tipo puede acabar con cosechas completes. En California por ejemplo en 2015 OFF ocasiono perdidas que alcanzaron los 16, 400 millones de dólares.
Cómo y cuándo llegó a los Estados Unidos
OFF se registró por primera vez en Hawái en 1946, y ahora ataca a casi todos los cultivos frutales comerciales que se cultivan allí, excepto a las piñas. La plaga se detectó por primera vez en California en 1960 y se ha reintroducido cada año desde 1966 a través del transporte de frutas y hortalizas infestadas.
Los cultivos sufren daños cuando las hembras de la mosca de la fruta depositan sus huevos dentro de la fruta. La forma más común de propagación de esta plaga es a través del transporte clandestino en frutas llevadas por viajeros desde regiones infestadas o en paquetes de productos de cosecha propia enviados desde otros países a California.
Si usted desea reportar algo sobre alguna infestación de la mosca oriental de la fruta puede comunicarse al CDFA al 1-800-491-1899 o puede visitar el sitio de internet www.cdfa.ca.gov/plant/reportapest.