Richard Smith1, Eric Brennan2, JP Dundore Arias3, Daniel Geisseler4, Peter Henry2, Danyal Kasapligil5, Nicholas LeBlanc2, Karen Lowell6, Jeff Mitchell4, Joji Muramoto7, Radomir Schmidt4, Kate Scow4 and Yu-Chen Wang1
1 – UCCE Monterey; 2 – USDA ARS, Salinas; 3 – CSU, Monterey Bay; 4 – UC Davis; 5 – De La Valley Labs, Fresno; 6 – NRCS, Salinas; 7 – UC Santa Cruz
Lettuce production in the Salinas Valley has suffered unprecedented losses in the last three years due to infection with Impatiens Necrotic Spot Virus (INSV) and co-infection with soilborne pathogens. Pythium wilt (Pythium uncinulatum) has been the primary soilborne disease associated with INSV, but Fusarium wilt and other diseases have also been observed. Given that soilborne pathogens play a significant role in the observed losses and the lack of effective control measures, growers have been asking if there are practices they can employ to improve soil health that may reduce the frequency and intensity of outbreaks of soilborne diseases in their fields. However, it is not clear if the traditional practices used to manage the soil's chemical and physical characteristics that are known to improve soil health could also impact soilborne disease pressure. This article will briefly explore general strategies to manage soilborne diseases (with specific references to Pythium wilt of lettuce), as well as soil health, and their potential interrelationships.
Resistant varieties
For a plant disease to occur, three factors must be present at the same time: a susceptible host, a virulent pathogen, and a conducive environment. Soilborne diseases, just like any plant disease, need those three factors to occur, and therefore, all disease management strategies are aimed at disrupting or weakening the disease triangle. One of the most effective management strategies to control soilborne diseases is the use of tolerant/resistant cultivars. Selection of resistant varieties is a promising strategy for addressing Pythium wilt (https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=55733 ) as well as Fusarium and Verticillium wilts in head and romaine lettuce types (https://calgreens.org/wp-content/uploads/2022/04/monitoring-the-population-of-the-lettuce-fusarium-wilt-pathogen-in-california_2022.pdf and https://calgreens.org/wp-content/uploads/2022/04/verticillium-biology-epidemiology_2022.pdf . There may be limits to the effective use of resistant varieties due to the lack of resistance in desirable lettuce types and to the development of new races of the disease that have overcome current varietal resistance (e.g. Fusarium). As a result, other strategies are also much needed to fight pathogens; here we focus on ways to boost potential benefits of crop rotations and soil biodiversity in fighting soilborne diseases.
Rotations to reduce soilborne disease
Soilborne pathogens use different strategies to persist in the soil such as by 1) Forming chitin-based survival structures ; 2) by saprophytically colonizing plant debris as cellulose-based survival structures; and 3) by colonizing the root tissue of non-susceptible plants .
Crop rotations address the specific survival strategies of a pathogen and may provide specific or general suppression of soilborne diseases. A local example of specific suppression is broccoli's ability to suppress Verticillium wilt in subsequent lettuce crops when grown in rotations. Recent research suggests that broccoli rotations can be enhanced by the addition of crab meal amendment that is rich in chitin compounds to create a "substrate-mediated” microbial community shift which increased fungal antagonists and effectively reduced Verticillium dahlia microsclerotia in the soil by 50 – 78%, thereby reducing crop loss. However, there are only limited examples of rotations in vegetable production that provide specific suppression of soilborne diseases and none that specifically suppress Pythium wilt of lettuce.
Pathogens may be generally suppressed by the rotations with non-susceptible crops because their abundance in the soil usually declines with time. Types of rotational crops used, how frequently they are included in the rotation, and the length of non-host intervals, all influence how much disease suppression can be realized by rotations. Some soilborne pathogens persist in the soil for a very long time and are challenging to effectively reduce with rotations. One such example is the white rot of onions and garlic (Sclerotium cepivorum), whose sclerotia can persist for 20-30 years in the soil. In this case, even in the absence of a plant host, the organism will remain, and future plantings of susceptible crops may be infected. Other pathogens like Fusarium and Pythium, may persist in the soil as saprophytes infecting non-living plant tissue and only express themselves as diseases when a susceptible crop is planted. However, recent research on strawberries has shown that inclusion of rotations with weak hosts can result in a reduction in the amount of Fusarium oxysporum f. sp. fragariae. However, at present, this type of effect has not been shown for F.o. lactucae, which infects lettuce.
As the above examples illustrate, rotations can reduce Verticillium and possibly Fusarium, but other important pathogens, such as Pythium wilt of lettuce, have no field-based observations showing impacts of rotations to date.
What is soil health?
While the phrase ‘soil health' has become commonly used to discuss soil management and stewardship it is important to highlight that the phrase “is a metaphor, not a literal scientific construct” (Janzen et al. 2021). Metaphors like ‘soil health' are used in science to help us understand abstract concepts, because they can make us think about and relate to more familiar things such as our own health. Janzen et al. define soil health as “‘the vitality of a soil in sustaining the socioecological functions of its enfolding land.' And they add that “soil health reflects not the composition of soil per se, rather its capacity to promote the pertinent functions of the land in which it is embedded. This means that the term has little meaning for a soil divorced from its ecosystem, and that properties conferring such health depend on place and time.” So for example, an undisturbed sandy soil in the foot hills of the Salinas valley may be considered healthy if one is considering its ability to support beautiful native flowers, but may not be able to support vegetable production unless it is regularly amended with organic matter and fertilizers. In other words, ‘soil health' depends on who is looking.
Improving Soil Health
Practices to improve soil health for agricultural production mainly revolve around improving carbon management in the soil such as increasing soil organic matter. Sources of carbon to the soil in vegetable production on the Central Coast includes the incorporation of crop residues. For instance, broccoli residue commonly returns 3-4 tons/A of dry biomass to the soil of which 40-42% is carbon. However, given the low C:N ratio of the biomass, mineralization of a large portion of the residue occurs quickly. Inputs of soil carbon can be augmented using cover crops and compost. Cover crops with high C:N ratios are particularly helpful in this regard (https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=55520). In organic production, dry organic fertilizers often contain 30% carbon and, depending on the crops being grown, provide substantial quantities of carbon to the soil. Soil carbon can also be increased by reducing the loss of carbon from the soil by reducing tillage.
Additions of carbon have beneficial impacts on the soil by increasing the diversity, abundance, and activity of soil organisms by providing their carbon food source and facilitating the building of good soil structure that in turn provides good soil organism habitat. These stimulated beneficial organisms may, in turn, outcompete or predate upon pathogens and reduce impacts on crops. In addition, the same soil health practices can reduce abiotic plant stress by improving nutrient availability, reducing compaction, and enhancing drainage. These abiotic stresses can predispose plants to disease, as the defenses of weaker plants are more easily overcome. Reducing abiotic stress can lead to improved crop productivity even with pathogens present.
Growers recognize the benefits of increasing additions of carbon to the soil and have used these practices for many years. However, widespread use of over-wintered cover crop (Oct/Nov to Feb/March) has declined due to planting schedule conflicts; use of compost applications has also declined due to food safety concerns regarding the potential for composts to introduce pathogens of human health impacts. Given the risk of missing spring planting slots with over-wintered cover crops due to wet soils in the spring, some growers are looking at the use of fall-grown cover crops (Aug/Sept to Oct/Nov). This earlier planting window provides an opportunity for growers to grow the cover crops for 50 to 60 days in the fall and incorporate them into the soil before the onset of the rainy season. Fall-grown cover crops can produce 3 - 4 tons biomass/A in this short window which provides a substantial input of carbon to the soil (https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=54986 ). This is just one creative example of how growers can overcome constraints to the use of practices that improve soil health.
Measures of Soil Health
Numerous measures of soil health have been proposed. Examples include evaluating water infiltration rates, measurements of soil enzymes, evaluating the soil microbial biomass and many, many others. Soil health measures may be chemical, biological or physical. The USDA Natural Resource Conservation Service considers several factors when evaluating soil health. Two of the most critical are – is there enough carbon readily available to support abundant and diverse soil organisms and is the soil well aggregated and free of compaction so that the physical environment of the soil favors soil biological activity. Aside from management factors related to contaminants (e.g. excess salts) or disturbance (e.g. tillage), soil health is largely driven by biological activity in the soil.
Soil organic matter is a standard measure in most soil tests and offers insight into whether management is building or depleting soil carbon. But not all carbon is equally available to soil organisms. Carbon may be in chemical structures that are hard for microbes to break down and access as a food source, for example lignin in woody materials, or in forms with simple chemical bonds easily broken, for example sugars. Carbon exudates from living plant roots offer readily available carbon and is a primary driver for maintaining abundant microbial diversity and activity in the rhizosphere. Thus, an important practice in soil health management is to try to avoid long fallow periods when there are no living roots in the soil.
Measurement of Soil Carbon
The most straightforward and practical measure of soil health is measuring total soil carbon. The preferred method to measure soil organic carbon is dry combustion. This method, when corrected for soil carbonates, offers the most reliable and repeatable measure of organic carbon (5%). This test is available from many soil testing labs. Other methods for measuring soil carbon such as Loss on Ignition (LOI) and Walkley-Black Wet Digestion measure soil organic matter and then make an estimate of soil carbon based on this measurement. These methods are less accurate (20%) than the dry combustion method. Good reliable measurements of total soil carbon is the cornerstone method for evaluating soil health.
A portion of the total carbon is “active carbon” that is stored in more simple chemical structures that is available to feed soil biological activity. This form of carbon can be measured by the peroxide oxidizable carbon (POX-C) test. It may offer a more robust insight into how well management provides readily available carbon for soil microbes. For example, a long-term organic systems study with vegetable production in Salinas valley found that POX-C increased with frequent cover cropping and compost inputs (White et al. , 2020). However, this test and many others proposed by the research community are not currently offered by commercial soil labs. This is an indication that the surge of grower interest in soil health is in front of the ability of commercial labs to offer these services. However, commercial labs are responding to demand for soil health measures by growers and certification agencies and this situation may change in the future.
Some soil health assays can be done by the grower: measurements of CO2 respiration in a 24-hour incubation can be done with purchased test kits (e.g. Solvita). This test gives an indirect measure of the activity of soil microbes by measuring how much CO2 is evolved from soil in a 24 hour incubation. In addition, measurements of water stable aggregates which is also an indirect measure of soil health can also be conducted by growers using the SLAKES app on their cell phones. The test measures the stability of soil aggregates against falling apart when wetted with water. For more information go to: ( https://doi.org/10.1002/saj2.20012, and https://www.ars.usda.gov/ARSUserFiles/30501000/SoilAggStabKit.pdf ) .
At this point there are no locally calibrated baseline standards for California growers to compare their soil health test results against. The best approach for a grower is to carry out these tests and watch the trends in the results over time to get a sense if the practices are moving the soil health indicators in a positive direction and whether those changes correlate with positive impacts on crop health and productivity. In almost all cases, it is most helpful to compare results across time and management change in the same field. Inherent soil properties, for example texture, drainage, parent material, etc. may all influence some properties and thus comparisons across fields are less clear cut than those in a single field over time. Given all the research being conducted on soil health, there will undoubtedly be refinements to recommended soil evaluations to assess soil health.
If you choose to send soil samples to a lab out of state, it is important to keep in mind that soil tests are often designed with the local conditions in mind and soils from California my not measure up well when compared with soils from other areas (e.g. lower organic matter levels, higher salts, etc.).
Summary
Frameworks for soil health assessment have been proposed that can help growers identify practical indices that can guide them in assessing the health of their soils. Fundamental to all soil health practices, increasing carbon inputs, is critical to increasing soil microbial activity which may have an impact on suppressing soilborne diseases. Therefore, reliable measurements of soil carbon with the dry combustion test can provide a basic understanding of the impact of management practices on soil health. The impact of soil health practices on soilborne diseases still needs to be examined on a disease-by-disease basis, as undoubtedly each disease will respond differently to beneficial practices. Pythium wilt of lettuce is proving to be an elusive and difficult to understand pathogen; much more work remains to be done to understand biological processes that can effectively suppress it.
The soil health field is an area of active research by scientists collaborating with growers to test the concepts discussed above and to find ways to optimize suppression of soilborne diseases. These crucial collaborations will help us better understand the directions we need to go in to get a better handle on these issues.
For additional reading:
Soil Borne Diseases : Soil Health (ucdavis.edu)
- Author: Larry J Bettiga
U.S. EPA proposed changes to rodenticide labels for agricultural use: opportunity for public comment
Roger A. Baldwin, Professor of Cooperative Extension, UC Davis
Niamh Quinn, Cooperative Extension Advisor, UC South Coast Research and Extension Center
Rodents cause substantial damage and health risks in agricultural productions systems through direct consumption of fruit, nuts, and vegetative material; damage to the plant (e.g., girdling of stems and trunks); by providing a food safety hazard from contamination; damage to irrigation infrastructure; damage to farm equipment; burrow systems posing a hazard to farm laborers; posing a health risk through potential disease transmission; and increased soil erosion by water channeling down burrow systems, among other potential damage outcomes. They also cause substantial damage and food contamination risks in livestock holding facilities, food processing facilities, barns, and other agricultural-related structures. As such, effective management is needed to minimize these risks. The use of rodenticides is often considered the most efficacious and cost-effective tool for managing rodent pests, and as such, it is often included in Integrated Pest Management (IPM) programs designed to mitigate rodent damage and health risks. Given the significance of rodenticides in managing rodent pests, it is important to know that the U.S. EPA has recently released a list of Proposed Interim Decisions (PIDs) for public comment that, if approved, will substantially alter if and how rodenticides may be used to manage rodent pests in the near future. As such, we felt it was important to inform California's agricultural producers as to the extent of these proposed changes, and if you are so inclined, we have provided a link for you to provide public comment on the PIDs, as well as links to contact your Senate and Congressional representatives to ensure your opinion is heard.
All rodenticides are currently under review. These include first-generation anticoagulants (FGARs; chlorophacinone, diphacinone, and warfarin), second-generation anticoagulants (SGARs; brodifacoum, bromadiolone, difethialone, and difenacoum), zinc phosphide, strychnine, bromethalin, and cholecalciferol. Of these, only FGARs, zinc phosphide, and strychnine have labels for use against field rodents (e.g., ground squirrels, pocket gophers, voles, rats, and mice found in agricultural fields), but not all of these active ingredients can be used for all rodent species. As always, it is imperative to fully read a rodenticide's label before determining if it is appropriate for use against a particular species and in a specific situation. That said, the following are some significant changes that have been proposed that you should be aware of. Other potential changes have been proposed as well, so please check out the PIDs for additional details (linked at the end of this document).
- All rodenticides for field applications will become restricted-use products. This means that applicators will need to be certified to use restricted-use products in these settings. They will also have increased reporting requirements for their use.
- Aboveground applications would be eliminated in rangeland, pastureland, and fallow land. This is a substantial deviation, as many/most applications in these areas have traditionally been through broadcast applications or spot treatments. This change would leave only bait stations for ground squirrels and voles.
- Within-burrow applications of FGARs will generally not be allowed in croplands during the growing season. This would eliminate FGAR application for pocket gophers for much of the year, and would eliminate it for all uses in some crops (e.g., citrus and alfalfa in certain areas of the state).
- Carcass searches will be required every day or every two days (starting 3-4 days after the initial application), depending on the product used and where applied, for at least two weeks after the last application of the rodenticide. When carcasses are found, they must be disposed of properly. Any non-target mortalities must be reported to the U.S. EPA. Collectively, this will require a major increase in labor, potentially making rodenticide applications impractical in many settings.
- Extensive endangered species designations are anticipated that will limit or eliminate the potential to apply rodenticides. This could have large-scale impacts, although the full extent is not known at this time.
- New labels will require the use of a PF10 respirator and chemical resistant gloves during application. This is a substantial change for some rodenticide labels, requiring fit testing for all applicators, with the requirement of respirators ultimately making rodenticide application more physically challenging.
Additional details on these proposed changes can be found at the following websites:
- Anticoagulant PID: https://www.regulations.gov/document/EPA-HQ-OPP-2015-0778-0094
- Zinc phosphide PID: https://www.regulations.gov/document/EPA-HQ-OPP-2016-0140-0031
- Strychnine PID: https://www.regulations.gov/document/EPA-HQ-OPP-2015-0754-0025
- Bromethalin and cholecalciferol PID: https://www.regulations.gov/document/EPA-HQ-OPP-2016-0077-0024
As mentioned previously, these proposed changes are likely to have a substantial impact on the use of rodenticides in agricultural settings. However, these changes are currently open for public comment. If you would like to comment on these proposed changes, the required links and useful guidance can be found at the following website: https://responsiblerodenticides.org/.
You may also comment on these proposed changes to your Senate and Congressional representatives. If you are unsure who they are or how to contact them, check out: https://www.congress.gov/contact-us.
The deadline for making comments to the U.S. EPA is unfortunately short, with a final deadline of February 13, 2023. Therefore, you will need to provide your comments in short order.
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- Author: Michael D Cahn
Please join us for a weekly lunchtime seminar series. Each week we'll be joined by a guest speaker for a 30-minute presentation followed by questions from the listeners and more general discussion.
The Zoom link will be the same each week. No pre-registration required.
Meeting link:https://ucanr.zoom.us/j/95260378391?pwd=TXNTNmtNalo5TzY0bjdISEszeXRXUT09
*The presentation (not the Q and A discussion) will be recorded and made available.
Habrá traducción al Español
Date |
Topic |
Tuesday, January 24 |
Nitrogen Mineralization from Organic Fertilizers and Composts Joji Muramoto, Organic Production Specialist, UC Santa Cruz |
Tuesday, January 31 |
Tools and Approaches for Assessing and Improving Irrigation Efficiency on the Farm Michael Cahn, Irrigation and Water Resource Farm Advisor, UCCE |
Tuesday, February 7 |
Organic Management of Nematodes Philip Waisen, Vegetable Crops Advisor, UCCE |
Tuesday, February 14 |
How to Identify and Scout for Insect Pests Alejandro del Poso, Assistant Professor of Entomology, Applied Insect Ecology - Turfgrass and Ornamentals, Virginia Tech University |
Tuesday, February 21 |
Why, How and When to Choose Between Open-pollinated, Hybrid, and Land-race seeds? Charlie Brummer, Director and Professor, Center for Plant Breeding, UC Davis |
Tuesday, February 28 |
Management of Soilborne Plant Pathogens with Organic Amendments Amisha Poret-Peterson, USDA-ARS, Davis |
Tuesday, March 7 |
Biology and Management of Thrips and the Diseases They Spread Daniel Hasegawa, USDA-ARS, Salinas |
Tuesday, March 14 |
Weed Management on Small farms and in Organic Production Systems Darryl Wong, Executive Director, Center for Agroecology & Sustainable Food Systems, UC Santa Cruz |
Tuesday, March 21 |
Recruiting Owls and Raptors for Pest Management Breanna Martinico, Human-Wildlife Interactions Farm Advisor, UCCE |
Questions? Contact Margaret Lloyd mglloyd@ucanr.edu, Aparna Gazula agazula@ucanr.edu or Lucy Diekmann lodiekmann@ucanr.edu
- Author: Michael D Cahn
CropManage Hands-on Workshop
Bringing Irrigation and Nutrient Management Decision-Support to the Field
Date: Wednesday, January 18th, 2023
10:30 am – 2 pm
Location: Watsonville Public Library
275 Main St., Suite 100, Watsonville, CA 95076
- Learn how to use CropManage to support irrigation and nutrient management decisions and record-keeping for your crops
- Learn about the latest updates to CropManage
- Learn how CropManage can assist with reporting requirements for Ag Order 4.0
CropManageis a free online decision-support tool for water and nutrient management of vegetables, berry, agronomic, and tree crops. Based on in-depth research and field studies conducted by the University of California Cooperative Extension, CropManage provides real-time recommendations for efficient and timely irrigation and fertilization applications while maintaining or improving overall yield.
At this free workshop, we will provide hands-on training so that you can learn to use the newest version of CropManage. Crops currently supported include many vegetables (carrots, cabbage, celery, broccoli, lettuce, tomato, spinach, etc.), berry crops (raspberry and strawberry), tree crops (almond, walnut, pistachio, prunes, and pear), and agronomic crops (alfalfa and corn). CropManage is also available in Spanish.
Who should participate? Growers, farm managers, other farm staff, crop advisors, consultants, and technical service providers are welcome. The workshop is for both new and current CropManage users. Spanish translation will be available. Lunch will be provided.
What to bring? This is a participatory workshop. Please bring a tablet or laptop computer so that you can follow along and participate in the exercises. Each participant will need a user account for CropManage. Please set up a free user account at https://cropmanage.ucanr.edu/ before the workshop. Please arrive early to set up your laptop or tablet computer on the wifi and get logged on to CropManage.
Registration is free: Please register at https://surveys.ucanr.edu/survey.cfm?surveynumber=39745
January 17th, 2023. Seats are limited to the first 25 registrants.
Questions: Contact Michael Cahn at mdcahn@ucanr.edu / 831-214-3690 or Sacha Lozano at slozano@rcdsantacruz.org / 831-224-0293
Agenda
10:30 – 10:50 am Registration and computer set-up
10:50 – 11:20 am Introduction
11:20 – 12:00 pm Getting started with CropManage
12:00 to 12:30 pm Lunch break
12:30 – 1:15 pm Using CropManage for decision support and record-keeping
1:15 – 1:45 pm Group exercise
1:45- 2 pm Discussion /Q&A/ wrap up
Continuing Education Units (CEU) for Certified Crop Advisors (CCA) have been applied.
NOTE: The following COVID-19 guidelines will be applied to this training workshop.
- Wearing a face covering during the workshop is recommended
- Stay at home if you have COVID-19 symptoms, tested for positive, and/or close contacts with or exposure to others who have been tested for COVID-19.
- Face masks and sanitation items will be provided at the workshop.
- Author: Richard Smith
- Author: Kirsten Pearsons
- Author: Yu-Chen Wang
Richard Smith, Vegetable Crops Advisor; Kirsten Pearsons, Entomology Advisor; and Yu-Chen Wang, Plant Pathology Advisor, UCCE Monterey, Santa Cruz and San Benito Counties
This is just a reminder of the need to control weeds on ranches this winter to reduce the overwintering habitat for Impatiens Necrotic Spot Virus (INSV). In the absence of lettuce fields during the winter, INSV survives in winter weeds. Daniel Hasegawa has identified the top ten weed hosts for INSV (Table 1) from survey work conducted over the past three years. Seven of the ten are common winter weeds that can be found along roadsides and in equipment yards, ditches, around valves, on banks and other areas on ranches. The winter provides an excellent opportunity for us to strike a blow to the survival of INSV in these and other key winter weeds.
Table 1. Top ten weed hosts of INSV and their seasonality (from Daniel Hasegawa)
In addition to controlling weeds on ranches, it is important to look at areas surrounding your farms. Weed hosts commonly occur around industrial and commercial sites. In early 2022 we observed an outbreak of INSV that was traced to patches of weeds in an industrial site that escaped everyone's attention. This winter, it is important for growers to pay attention to weeds on properties that are adjacent to their farms. Talking with neighbors and getting them to control weeds in areas that may seem unimportant is critical to curbing early-season outbreaks of INSV. Most neighbors are probably more than willing to control weed host plants if asked. But on properties where the property manager is uncooperative, an infestation of weeds that harbors a pest that threatens lettuce can be deemed a nuisance and be subject to a weed abatement order by the County Agricultural Commissioner.
The Grower Shipper Association (GSA) has been working with the Monterey County Dept. of Public Works and the Board of Supervisors to streamline the process controlling weeds along county road right-of-ways. The process involved a modification of an encroachment permit to allow growers to treat weeds on the county right-of-way that boarder their ranches. Below is a description of the process provided by Chris Valadez, President, GSA:
The County of Monterey recently adopted an urgency ordinance authorizing a temporary encroachment permit (permit) to Grower-Shipper to eradicate weeds on County rights-of-way, namely along County roads, as a new tool to protect against the spread of INSV.
How this Works:
(1A): A farm, licensed pest control advisor, or contracted licensed advisor (inc. pest control business) must complete and return this use 'agreement' and request a unique copy of the permit from Grower-Shipper, by email: joann@growershipper.com. The agreement must be completed and returned to joann@growershipper.com after which a copy of the permit will be issued.
If a farm intends to conduct weed abatement in a County right-of-way adjacent to their farm property, they must contact the Monterey County Ag Commissioner's Office to add adjacent, off-farm areas to their permit and subsequently follow pesticide use reporting requirements.
OR:
(1B): If you intend to eradicate weeds in areas either adjacent to a farm, in a County right-of-way (along a County road), or areas not adjacent to a farm but are in a County right-of-way along a County road, the farm, licensed pest control advisor, or contracted advisor (inc. pest control business) must complete and return this use 'agreement' and request BOTH a unique copy of the permit and a copy of Grower-Shipper's Operator ID documentation, by email: joann@growershipper.com. The agreement must be completed and returned, after which a copy of the permit and Operator ID information will be issued. Here, instead of performing the abatement under a farm's permit, the abatement would be conducted under Grower-Shipper's Operator ID. You are responsible for pesticide use reporting under this Operator ID.
Once you have a completed use agreement, a unique permit copy, and Grower-Shipper's Operator ID documentation (if applicable), you may proceed by giving a minimum 48-hour advance notice or Notice of Intent, indicating the anticipated date, time, and location of where the abatement will be conducted. Please include your permit copy with your advance notice in an email to Encroachment@co.monterey.ca.us, copying/cc: joann@growershipper.com.
If you have a question about whether a certain area is in fact along a County maintained road, visit maps.co.monterey.ca.us/wab/parcelreportwebapp/ to identify the area in question and to find if it is a County 'maintained' road.
To discuss this further, contact chris@growershipper.com.
In summary, INSV is at its most vulnerable state during the winter and efforts that we take to control them can help reduce problems later. For the most part, INSV is surviving in the winter weeds and efforts to control the weeds can go a long way to reduce the loads of the virus for the start of the 2023 lettuce production season.