Month: November 2023

By: Kirk Williams, Lecturer-Texas Tech University

While there are many methods to control weeds, weed control with herbicides remains a viable option due to its lower cost versus other options such as mechanical cultivation.  When herbicide applications are done efficiently it can be a much faster process when compared to mechanical cultivation. 

  Application of herbicides through nozzles is important for correct herbicide distribution and dosage over the target.  The target could be existing weeds in the case of post emergent herbicides or the soil surface with pre-emergent herbicides or a combination of both existing weeds and the soil surface in the case of tank mixing post emergent and pre-emergent herbicides.  Coverage is critical for herbicides to work effectively.  Hydraulic spray nozzles create a wide range of droplet sizes.   These droplets are measured in microns with droplets from 200 to 400 microns considered the most appropriate size for herbicide applications.   Larger droplet sizes may bounce or roll off leaves while very fine droplets are more prone to drift.

  To provide satisfactory results, recommendations from Syngenta, one of the manufacturers of water sensitive cards, is to have 20 to 30 droplets per square centimeter for pre-emergent herbicides. For post emergent herbicide applications, it is recommended to have 30 to 40 droplets per square centimeter.   A square centimeter is about 1/6 of a square inch. 

  One way to increase and improve coverage in herbicide applications is to use a double nozzle body.  This allows two nozzles to occupy the same space as one nozzle.  The double nozzle body allows you to easily increase the volume of coverage no matter what kind of nozzle you using. This is especially true when you have to use a relatively large spray nozzle to apply higher volumes.  Larger sprayer nozzles tend to produce coarser droplets.  Splitting the required flow into two nozzles can produce an efficiency gain by decreasing the number of coarse droplets.  The double nozzle body also helps with increasing droplet coverage of target.  (See the double nozzle body set up in Image 1).

  It was found in a study with water sensitive cards that coverage was increased by 20% when double nozzle bodies were used when compared to single nozzle bodies.   The study used regular flat fan off center 03 nozzles, calibrated to deliver 47 gallons per treated acre and the water sensitive cards were placed on the berm underneath the grape vines.   While the double nozzle body had higher coverage the droplets per square centimeter went down due to the droplets running together versus the single nozzle body.  The single body nozzle had 43 droplets per square centimeter while the double body nozzle had 17 droplets per square centimeter but the droplets are much bigger.  (See the water sensitive cards in image 2).   While the droplets per square centimeter are out of the recommended range for droplets per square centimeter for herbicides with the double nozzle body the better coverage should result in similar or better weed control with both pre-emergent herbicides and post emergent herbicides. 

  Herbicide application technology has improved with a wider selection of nozzles available.  Adoption of these newer type of nozzles has been widely adopted in row crops but may be not as widely adopted for vineyard herbicide applications.  These newer type nozzles reduce drift but still deliver good weed control. 

  Air Induction nozzles are a newer type of nozzle that are available in a wide range of spray tips.  The air-induction nozzle is noted for producing large drops through the use of a venturi air aspirator. The venturi draws air into the nozzle through holes in the side of the nozzle and then the air is mixed with the solution to create larger spray droplets, which reduces drift potential.   These larger droplets are filled with air bubbles and explode on impact with the target surface and produce coverage that is similar to other nozzle types. 

  Many sustainable grape growing standards include drift management as a component of their plans.  The incorporation of air induction nozzles that reduce drift by reducing the number of fine, drift prone droplets could be a part of meeting the requirements of these standards.  Drift reduction is important during the growing season to reduce phytotoxicity due to herbicides.  When herbicide applications take place in the in dormant season, phytotoxicity to the grapevines is not an issue but with the wide spread adoption of cover crops, herbicide applications need to stay where they are intended to be, so they don’t impact the cover crops.     

  In a study, double nozzle bodies were equipped with air induction under banding nozzles (AIUB8503), calibrated to deliver 44 gallons per treated acre.  Water sensitive cards were placed on the berm underneath the grape vines.  This nozzle configuration delivered 56% coverage of the water sensitive cards and produced 26 droplets per square centimeter.  As you can see, in the water sensitive cards in (image 3) the droplets produced are large with few small droplets.  The droplets per square centimeter are in the recommended range for droplets per square centimeter for pre-emergent herbicides but outside of the recommended range for post emergent herbicides.  The coverage produced should result in similar or better weed control with both pre-emergent herbicides and post emergent herbicides when compared to the regular nozzle set up.  The air induction nozzles will also produce a minimum of drift prone fine droplets.  

  Adoption of double nozzles bodies into your herbicide application program will increase coverage for both pre-emergent and post emergent herbicides.   Switching to air induction nozzles is one way to make sure the herbicides that you are using stay where they are intended to.   

  In addition to coverage and nozzle selection, don’t forget about integrated weed management principles.  These principles include knowing and correctly identifying your weed problems so that appropriate herbicides can be chosen.  Controlling weeds when they are small when they are more susceptible to herbicides and easier to have better spray coverage.  Another integrated weed management principle is to keep annual weeds from going to seed which reduces the weed seed bank in the soil.   Other principles include rotating among herbicides with different modes or action or tank mixing herbicides with different modes of action together which helps manage weed population shifts as well as herbicide resistance.  Staying clean is easier than trying to clean up a mess, so pre-emergent herbicides may help to keep the vineyard berms clean.  

  Kirk Williams is a lecturer in Viticulture at Texas Tech University and teaches the Texas Tech Viticulture Certificate program.  He is also a commercial grape grower on the Texas High Plains.  He can be contacted at kirk.w.williams@ttu.edu

By:  Judit Monis, Ph.D. – Vineyard and Plant Health Consultant

New methods are being applied for the testing of imported plants and the certified foundation mother blocks at the University of California at Davis that manages the foundation blocks for the California (CDFA) certification program.  After so many years of considering the biological indexing technique a gold standard, the methodology has been replaced with modern technology that is able to detect any virus in the propagation material.  Furthermore, due to the infection and spread of Grapevine red blotch virus (GRBV) in the former CDFA (Russell Ranch) certified foundation block, new measures are being applied to avoid that the problem occurs again. 

Plant Quarantine Programs

  Plant quarantine programs have been developed worldwide to reduce the risk of introducing foreign plant pests and/or pathogens not found in a particular state, country, or region.  My expertise is plant pathology and throughout my career I have specialized in the application and development of methods for the detection of bacteria, fungi, and viruses that cause diseases in vineyards and fruit orchards.  In spite of the current existence of plant quarantine programs, most grapevine pathogens with rare exceptions occur in all grape growing areas in the world.  The reason is that in most cases, quarantine programs were implemented after the introduction of the infected plant material.  In addition, modern techniques for the detection of these pathogens were not available at the time of plant introduction. In other words, the majority of grapevine pests and pathogens were moved unknowingly.  The advancement of science and the use of sophisticated detection methods for grapevine pathogens and isolation has helped keep certain viruses outside of Australia.  For example, Grapevine fanleaf (GFLV) has not been reported in Australia as of yet.  Presently, with the use of advanced methodologies, new pathogens continue to be discovered. As science progresses with the development of more refined technology (e.g., next generation sequencing also known as high throughput sequencing), it is expected that new (or unknown and established) pathogens will be discovered. In practice, most grapevine pathogens have originated at the centers of origin of Vitis species (a plant genus that includes both table, wine, and rootstock grapevine varieties) and moved to many grapevine growing areas of the world during plant introduction. 

  In the United States, the United States Department of Agriculture (USDA) Animal and Plant Inspection Services (APHIS) Plant Pest Quarantine (PPQ) unit regulates the introduction of plant material for planting from foreign countries.  However, the USDA does not have a centralized government plant quarantine center.  Instead, the APHIS PPQ  issues permits to specific clean plant centers with proper containment facilities and approved protocols to manage the quarantine of specific crops. For grapevines, two importation centers are available for introducing quarantined planting material: The Foundation Plant Services (FPS) at the UC at Davis and the Clean Plant Center at Cornell University in Geneva, New York.  

Grapevine Certification Programs

  Grapevine certification programs are needed to produce tested plant material that is free of important known pathogens.  These plants are then distributed to nurseries that propagate and sell these plants to growers.   In the United States, certification programs are voluntary and are managed by individual states.  I will describe the California certification program as many US grapevine growing regions purchase planting material from California nurseries. 

  The Grapevine California Registration and Certification (R&C) Program was first written into law in the 1980’s.   The Grapevine R&C Program is administered by the California Department of Agriculture (CDFA) and provides for the testing of source vines for grapevine viruses that cause important diseases. Registered sources and certified nursery stock are periodically inspected by the CDFA staff and are maintained by the participant nurseries.   Starting in 1996, I participated and provided input at the industry meetings that lead to the revision of the California Grapevine R&C program many years later.   In 2010 the Grapevine R&C program was revised to include testing of foundation mother vines for the presence of a comprehensive list of viruses.

  The California Grapevine R&C Program rules can be found in CDFA’s website:  https://www.cdfa.ca.gov/plant/pe/nsc/nursery/regcert.html

  With funding from the National Clean Plant Network, a new of foundation block named Russel Ranch was planted at the UC Davis in 2009.   The planting material (both scion and rootstock varieties) included in the new foundation block had to pass a rigorous testing program and have been propagated using the “apical micro-shoot tip culture” technique.   The apical micro-shoot tip culture process is a plant tissue culture technique that is used to eliminate pathogens from vegetative propagated plant material.  The testing program at UC Davis is known as Protocol 2010.  The maintenance and testing of the scion and rootstock mother blocks are performed by UC Davis FPS personnel.  Shortly after the update of the California Grapevine R&C Program, GRBV, a virus of significant importance for the vineyard industry, was discovered.  Consequently, the California Grapevine R&C Program was revised to include the testing of foundation and nursery increase blocks for the presence of GRBV.  Sadly, the Russell Ranch foundation block became progressively infected with GRBV.  The infection status was so high that FPS had to suspend the sale of plant material to nurseries. 

  The testing of the foundation mother plants includes a list of well characterized viruses, Xylella fastidiosa, and phytoplasmas using biological, serological, and molecular testing techniques (https://fps.ucdavis.edu/fgr2010.cfm).  The nursery increase blocks are inspected and tested by CDFA personnel with a reduced number of pathogens.  The updated Grapevine R&C added the testing for the detection of GRBV using the polymerase chain reaction (PCR) to vines in the foundation and nursery increase blocks.  Related to nursery certified plants, the rules are vague and state that certified plants may be tested (particularly if after inspection suspected symptoms are observed).  According to CDFA, the goal is to test a statistical sample with a 95% confidence level assuming a 1 % disease incidence.  It is disappointing that in spite of the importance of the decline and canker diseases caused by fungal pathogens (and how easily the pathogens can be transmitted by activities carried out at the nursery), the regulations do not include inspection or testing for fungal pathogens in foundation or increase blocks. 

  The use of certified material is expected to be less risky than planting field selections of unknown infection status.  However, it is always prudent to consult with me to assure that the planting material meets the expected cleanliness standards. An important piece of advice when working on the procurement of clean planting stock is to plan in advance.  Most nurseries in California collect cuttings for budwood as soon as the vines are dormant.  However, grafting activities are performed during the spring of the following year.  Planning with time will allow for inspection of the increase blocks early in the fall before a freeze.   Being familiar with the nursery’s operations and their staff is important.  Good communication will help with scheduling inspections and testing of the increase blocks from which bud wood and rootstock cuttings will be collected. 

Changes in the Testing and Management of UC Davis Grapevine Foundation Block and Introduce Quarantine Plant Material

  The FPS laboratory at UC Davis performed comparative studies between the traditional biological indexing technique and the high throughput sequencing (HTS) methodology.  To refresh my readers, the biological indexing technique or commonly known as woody indexing is an ancient method that relies on the grafting of grapevine (or other woody species) material onto an indicator host.  An indicator host, is a plant variety that is very susceptible to the disease we wish to detect.  For example, the indicator host for grapevine leafroll disease is  Cabernet Franc.  To perform the assay, buds from quarantine or foundation plants are grafted onto the indicator plants.  After a period of time (generally two years) the symptoms of the grafted plants are recorded. If the  buds of the grapevine plants that we wish to test for are infected with a virus that causes red leaf discoloration, and successfully transmits the virus to the indicator plant, it is concluded that the test vine is infected with a Grapevine leafroll associated virus (GLRaV). 

  However,  GRBV also causes red leaf symptoms in Cabernet Franc and other red grape varieties, therefore the test vines could be infected with GRBV.  In more simple words, the biological indexing technique is able to detect disease symptoms and not a particular pathogen that causes it. As long as there is a detection, there is no problem.  The problem occurs when a vine is infected but no symptoms are visible in the indicator plants.  In this case, the vines would be considered healthy and will spread a disease-causing agent.  After a series of experiments and discussions with regulators at USDA APHIS PPQ and CDFA, UC Davis FPS personnel have been able to implement the use of HTS instead of the woody indexing assay. This is a welcomed change I sincerely never expected to happen during my professional life! Another important needed change in the management of the UC Davis foundation plants is the construction of an insect-proof greenhouse that will host the CDFA certified mother vines.  The greenhouse is expected to be finished by the end of 2023.

Conclusions

  Diseases, pathogens, and/or their vectors do not know or respect the borders between blocks (at the nursery, foundation block, or your vineyard).  Even if the planting material came from a reputable certification program, paying attention to the surrounding vineyards as well as having knowledge of the potential presence of disease prior to planting is important.  The planning of a new vineyard is not trivial and requires specialized knowledge.  I am available to help look for suspicious symptoms (inspect scion and rootstock source blocks), evaluate the planting site, develop a testing plan based on science and statistics, and review nursery and vineyard disease testing history.  

  Judit Monis, Ph.D. provides specialized services to help growers, vineyard managers, and nursery personnel avoid the propagation and transmission of disease caused by bacteria, fungi, and viruses in the vineyard.   Judit (based in California) is fluent in Spanish and is available to consult in all wine grape growing regions of the word.  Please visit juditmonis.com for information or contact juditmonis@yahoo.com to request a consulting session at your vineyard.

How AI and Other Technologies Are Changing the Landscape for Vineyards & Wineries Worldwide 

By: Cheryl Gray

From grape-picking robots to mechanized pruning machines, just name it, technology has a cutting-edge answer for virtually any vineyard need to reduce dependence upon manual labor.

  Studies show that technology-driven equipment is becoming increasingly used in the viticulture industry. When deployed, those studies show that the results show greater productivity when it comes to caring for and, eventually, harvesting grapes. 

Westside Equipment Company is one of the corporations at the forefront of making this a reality for its clients. A global leader in its field, Westside Equipment is headquartered in  Madera, California in a grape-growing region designated as an American Viticultural Area (AVA) since 1985. The company, which also has three other locations in the Golden State, has been in business for nearly 40 years.

  Westside Equipment Company, which designs and manufactures harvesting equipment at its Madera location, recently acquired VMECH for its portfolio, adding an entire new line of technology-driven vineyard products, including the Chariot Mechanized Vineyard Pruner. Stephanie Hawkins is the marketing and sales coordinator for the company.

“The VMECH Chariot’s dual precision pruner adapts to various trellis types and enables pre-pruning and near finish pruning, covering up to three acres per hour and  saving up to $600 per acre. With a vision-based approach, our AI technology identifies and scans the cordons, adjusting based on the incoming data. The versatile Chariot has multiple attachment options to keep it useful year-round, including shoot thinning and trunk suckering. A single row pruning unit will be available in fall 2023.”

  The Chariot is useful for applications that include work on high wire, VSP and quad trellises. According to Westside, the equipment is built to supplement pruning capacity and comes equipped with individual joysticks for seamless operation. While the machine requires three operators, it promises to save money by pruning two rows at a time and one to three acres an hour, depending on row spacing and length. 

  Another feature of the Chariot is that its pruning heads are efficient, versatile, and can be customized. The heads attach to each of the machine’s booms. In addition to its pruning capabilities, the Chariot can be used to cane-cut vineyards in spring.

  The VMECH Toolbar is another vineyard productivity tool. The unit is designed to be mounted on virtually any tractor, with Westside Equipment providing manufacturing assistance to ensure a proper fit. Customer support, Hawkins says, is important to Westside Equipment.

  “All Westside Equipment Company products are custom built at our manufacturing headquarters in Madera, California and come with 24/7 in-season service and parts (limited to California vineyards) to conveniently serve the wine grape industry,” Hawkins said.

  For companies that take over when the grapes arrive at the winery, Prospero Equipment Corporation considers itself a frontrunner in supplying processing and packaging equipment for wineries of every size. The company, founded in 1972, started as a supplier to home winemakers. 

  In the 1980s, Prospero expanded into commercial wine-making equipment, opening an office in California to begin servicing and distributing products from Italy to West Coast wineries. The product roster includes imported tanks, fillers, labelers, commercial presses, filters and crusher destemmers. The family-owned and operated business now specializes in offering the latest technology to help wineries keep pace in an ever-changing industry.

  Prospero represents SK Tank, which builds wine tanks, wine presses and equipment for other beverage industry sectors. Andy Robinson represents Prospero’s sales division.

  “Working with SK allows Prospero to offer full tank storage capabilities as well as supporting harvest equipment,” Robinson said. “Prospero’s brewhouse division offers the highest quality brewhouses and beer tanks accompanied by full engineered designs and complete turnkey installations.”

  Robinson adds that Prospero has recently launched new products that focus on the use of technology, thanks to a newly formed relationship with GAI Machinery, which Prospero now represents.

  “GAI sets the upper standard of machine manufacturing and offers the highest quality packaging equipment available,” Robinson said. “Prospero now offers a revolutionary new technology with the UNICA filling valve, which is an Electro Pneumatic filling valve capable of filling from 0 – 6 BAR pressure. This has allowed many companies to expand their product lines and be able to package all of them within the same Monoblock. The UNICA filling valve is now also available with a Volumetric Electro Pneumatic filling valve, offering the most precise filling for a wider range of container sizes and formats. Offering still and counterpressure filling in the same filling valve has brought the new technologies to the forefront of packaging for the beverage imdustry. The UNICA filling valve is also offered on the GAI canning Monoblocks. The GAI Monoblock design is engineered so all main gears are interlocking and connect all turrets, thus eliminating any risk in loss of machine timing.”

  Robinson adds that Prospero has multiple ways to help its clients with products and services, identifying the absolute essentials for wineries that want to keep up with the latest technology.

  “Prospero offers sales consulting, engineered drawings, parts departments and a technical team for service, installation and training,” Robinson said. “Having effective product and packaging consultation allows direct discussions for future growth and wiser investment strategies. Providing engineered drawings allows for a seamless installation, parts to be on hand if needed and a direct format for our technical team to follow.”

  Robinson says that planning ahead is the key to keeping up with technology.

  “A company should plan for future development of products and production volumes, this also includes added closures and perhaps canning,” he said. “Investing in high quality equipment helps guarantee longevity, ease in maintenance and the finest quality finished product. Prospero technicians fully train all new equipment owners after installation to guarantee all operators are knowledgeable about the machinery and the supporting equipment. This support is backed up by our service and parts department for maintenance and repairs.”

  Experts say that the cost of labor is the biggest expense grape growers face every season. With the declining number of farm workers available to work the vineyards, those experts say there is a serious labor shortage. The answer for many growers is technology replacing workers to do the tasks of pruning, shoot thinning, shoot posting, fruit thinning, leaf removal and row line cultivation.

  Gearmore, Inc. specializes in implements for those many operations. Gearmore, Inc. has provided quality vineyard implements through servicing tractor dealers for 60 years. To cover all the grower’s requirements, the company has more than 100 different models, with widths and capacities of products for vineyards to handle varying acreage, row widths, terrain, foliage profile and different tractor horsepower.

  Gearmore is headquartered in Chino, California and boasts the largest inventory of implements on the West Coast. Its reach is global and includes sales representatives in charge of territories throughout the southwestern United States, Hawaii and parts of Mexico. Vineyard equipment options include in-row cultivators, air blast sprayers, soil conditioners, air sprayers, boom sprayers, vine trimmers, leaf removers, pre-pruners, compost spreaders, mowers, soil conditioners, mower shredders and more.

  There are other technologies in use by vineyards, such as drones, satellite imagery and GPS. Larger operations use these technologies to monitor vineyard health, and smaller vineyards are following suit. Through satellites and drones, vineyards can easily gather data, including the ripeness of grapes, water shortages and the early signs of vineyard disease. The technology can also help protect the environment because products must only be sprayed for disease and pests when necessary.

  As for wineries, experts say that platforms that merge statistics, such as point of sale, club memberships and e-commerce help streamline sales and improve customer experience.

  In short, technology, including AI, is increasingly becoming the norm rather than an anomaly for vineyards and wineries. Its widespread use is now seen as a way to advance productivity and sales in a highly competitive industry where smart moves driven by technology make money.