Pest Management Guide for Grapes in Washington - 2019 WASHINGTON STATE UNIVERSITY EXTENSION EB0762 - Computing ...
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2019 Pest Management Guide for Grapes in Washington W A S H I N G T O N S TAT E U N I V E R S I T Y E X T E N S I O N • E B 0 7 6 2
EB0762 Pest Management Guide for Grapes in Washington—2019 POISON EMERGENCY Washington Poison Center: 1-800-222-1222 https://www.wapc.org/ For further information, see Pesticide Safety PESTICIDE LABELS YOU ARE REQUIRED BY LAW TO FOLLOW THE LABEL. It is a legal document. Always read the label before using any pesticide. You, the grower, are responsible for safe pesticide use. Trade Names Trade (brand) names are provided for your reference only. No discrimination is intended, and other pesticides with the same active ingredient, provided they are also registered for use on the intended crop and for the intended target, may be suitable. No endorsement is implied. Pesticide Information National Pesticide Information Center: 1-800-858-7378 http://npic.orst.edu/ Spray Guide Coordinators Gwen Hoheisel, Regional Extension Specialist Michelle Moyer, WSU Extension Viticulturist Front Cover Photos Michelle Moyer, WSU Extension Viticulturist SECTION COORDINATORS: Regulations & Safety Carol Black, WSU Pesticide Education Specialist Pesticides Catherine Daniels, WSU Pesticide Coordinator Weeds Lynn Sosnoskie, WSU Extension Weed Specialist Tim Miller, WSU Extension Weed Specialist Insects Douglas Walsh, WSU Extension Environmental and Agrichemical Education Specialist Gwen Hoheisel, Regional Extension Specialist Nematodes Inga Zasada, USDA-ARS Research Plant Pathologist Plant Diseases Michelle Moyer, WSU Extension Viticulturist Naidu Rayapati, WSU Extension Grape Virologist Prepared by representatives of Washington State University, WSDA and USDA personnel, and industry representatives. WSU Extension • Washington State University • Pullman, Washington
CONTENTS General Information........................................... 1 Pest Management Program for Grapevines.................................................... 24 Pesticide Safety.................................................... 1 Precautions in Use and Storage Diseases of Grapevines...................................... 29 Pesticide Disposal and Plastic Container Trunk and Root Diseases Recycling Foliar and Fruit Diseases Symptoms of Pesticide Poisoning Protections, Emergency Treatment, and Disease Management Program for Pesticide Information Grapevines.................................................... 35 Weed Control...................................................... 4 Viruses of Grapevines....................................... 44 Application Rate and Equipment Management of Grapevine Virus Diseases General Precautions Grapevine Leafroll Disease Factors Affecting Control Rugose Wood Complex (Grafted Vines) Soil-Applied Herbicides Grapevine Fanleaf and Grapevine Decline Foliar-Applied Herbicides Diseases Grapevine Red Blotch Disease Herbicide Injury................................................ 14 Potential Virus Diseases 2,4-D Drift Documentation Spray Recommendations ................................. 48 Weed Management Program General for Grapevines............................................... 15 Formulations Calibration of Vineyard Sprayers Pests of Grapevines........................................... 17 Dilutions Black Vine Weevil Brown Marmorated Stink Bug Regulatory Information.................................... 51 Cutworms Pesticide Residues on Grapes Drosophilla suzukii Pesticide Restricted Entry Standards Grape Flea Beetle Licensing Grape Leaffolder Chemigation Grape Mealybug State Laws and Regulations Grape Phylloxera Worker Right-To-Know Act Leafhoppers Horticulture Pest and Disease Boards Mites Tank Mixes Plant-Parasitic Nematodes Scale Insects Thrips
GENERAL INFORMATION The Pest Management Guide for Grapes in Washington LABEL and be certain that it is up to date. presents various chemicals and their uses against pest problems in Washington vineyards. While Always consult with your processor, winery rep- the recommendations are based on eastern resentative, or Extension agent if you have any Washington conditions, the information may questions on approved pesticides or pesticide uses. often be applied to similar pest problems found The registration status of various chemicals, for- throughout the state. Specific and more detailed mulations, and manufacturers’ products changes information on pests and diseases can be found rapidly. You may lose your crop or market if you in the Field Guide for Integrated Pest Management in misapply or use improper materials that leave ille- Pacific Northwest Vineyards (PNW644). gal residues on your crop. Recommendations are suggested guidelines. Pests Not on Product Label: Some suggested They are not intended to represent pest control uses of pesticides in this publication are for pests programs. The use of other materials and varying not listed on product labels. These are indicated by rates and treatments for control of particular pests the symbol '*'. Such uses comply with the federal depends on individual circumstances. law (FIFRA), which says a use is consistent with label directions provided the crop or site is on the Caution: Before making any application of chemi- label and directions concerning rates and interval cals to any vineyard, READ THE COMPLETE before harvest are followed. PESTICIDE SAFETY Precautions in Use and Storage providing emergency transportation for any exposure of concern. The web site http:// • Know the trade names and active ingredients pesticideresources.org has WPS resources to for the pesticides you are using. Be famil- assist grower’s understand their responsibili- iar with the first aid treatments, especially ties and has training information and tools. anything unique, before you store or handle pesticides. • Pesticide labels state the personal protective equipment (PPE) to be worn when handling/ • To protect your workforce, comply with the applying pesticides. At a minimum, long US EPA Worker Protection Standard (WPS) that is administered by Washington Depart- sleeved shirt and long pants are required ments for Agriculture and Labor & Industries. to protect your skin from exposure; usually WPA classifies employees as workers if they waterproof gloves too. If there is an added could be exposed while working in vineyards risk due for the product, the label may that were treated in the past 30 days. Or clas- require a coverall be worn over short sleeved sifies employees as pesticide handlers if they shirt/short pants or long sleeved shirt/long mix, load, apply, or conduct maintenance pants. The coverall can be a standard cotton on application equipment because they have or cotton polyester coverall; some opt for the possibility of direct exposure to pesticides a disposable coverall to reduce laundering while working. Agricultural pesticide labels hassles. To protect eyes, wear safety glasses state a Restricted Entry Interval (REI) for each with brow and side covers, a face shield, or crop. This REI is a time when no entry is goggles. Waterproof gloves and boots may be allowed into the treated area, unless the per- required; reusable nitrile gloves meet most son is provided extra protection as detailed label requirements. Lastly some products in the regulations and on the label. The may require a respirator to filter out particu- section of the label that addresses WPS is the lates or vapors/gasses from contaminated air. Agricultural Use Requirements section. The reg- Obtain a NIOSH-certified respirator, and if ulation requires notifying employees about needed, the appropriate chemical cartridge pesticides applied, training those employees, (most often an organic-vapor cartridge). monitoring the handling of highly toxic Dispose of any PPE that cannot be cleaned. pesticides, providing handlers clean PPE, and Wash all other PPE at the end of the task. 1
• Be aware of heat illness. By wearing PPE, • Collect spilled material and absorbent for your body does not cool as well. Washing- later use or hazardous waste disposal. Wash ton Labor & Industries has Outdoor Heat the contaminated area with soap and water. Exposure regulations for agriculture (WAC The breakdown of insecticides can be acceler- 296-307). It sets thresholds at 89°, 77°, and ated by using a weak lye solution. 52° depending on the number of layers of • Most pesticide labels prohibit applications clothing a person is wearing and if the layer during temperature air inversions. Inver- is non-breathable, like a rain suit. Acclimati- sions happen typically in the late afternoon zation, drinking water, and illness awareness as the air cools and settles, then lasts through are the main requirements. Schedule pesti- the night and early morning. It does not cide applications during the cooler parts of dissipate until the sun warms the soil the the day. next day and air starts to move around • Some insecticides are organophosphates or again. During an inversion, air cannot mix carbamates. They have caused poisonings vertically, and spray particles may be carried in Washington from unintended exposures horizontally for a great distance. New inver- during routine tasks. If either type of insec- sion meters are available to assess conditions. ticide product has the signal word of Warn- Unfortunately to combat the concerns for ing, Danger/Poison or Danger and they are heat stress, the coolest time of the day is best handled (mix, load, apply) for more than 30 to apply—just make sure there is no inversion. hours in a 30 day period, the Washington • Cover or remove food and water troughs Dept. of Labor & Industries (WAC 296-307- when spraying around livestock areas. Avoid 148) requires a medical monitoring program. contamination of fishponds, irrigation This is a blood testing protocol to monitor canals, streams, and lakes. Check wind direc- for exposures to reduce the chance on an tion often when applying in sensitive areas. accidental poisoning and to assist with treat- • Avoid drift of pesticides to other crops. ment. A pre-season blood test determines Again, check wind direction often. Check your normal cholinesterase activity level. equipment function, particularly look for If symptoms occur, seek medical treatment leaks and malfunctioning nozzles. immediately and they will retest your levels. There are antidotes to treat a poisoning; • Given changing wind conditions, plan your however, they are only administered by a application to keep the spray moving away medical professional. from you and if the wind changes, change your strategy. • Keep soap and water available for emergency decontamination for an unexpected expo- • Pesticides that persist for long periods of sure, such as from a broken hose. time in the soil may injure susceptible crops planted the following year and may result • Before recycling or disposal, triple-rinse in illegal residues. Observe label restrictions containers and pour rinsate into the spray concerning the intervals and crops which mixture you are making up. Puncture rinsed may be grown in treated soils. containers to ensure they cannot be reused. • Some pesticides may cause plant injury Offer rinsed plastic containers for pesticide under certain conditions or on certain variet- container recycling (see next section). Wash- ies. Be sure the material is recommended for ington State does not allow burning of used use on the plant to be treated and that condi- pesticide containers. tions are favorable for application. • Keep your pesticide storage area locked. Keep • Some processors may not accept a crop used, empty, triple rinsed pesticide contain- treated with certain pesticides. If crops are ers in your storage area. going to a processor, be sure to check with • Do not use your cell phone, smoke, chew their field representative before applying tobacco, or eat while spraying or while your pesticides. hands are contaminated with concentrate • When a permanent vineyard crop cover has products or a spray batch. flowers, the cover must be mowed before • Mix pesticides according to label directions spraying insecticides that are toxic to bees, and apply at the recommended rate. and to protect all pollinators. 2
Pesticide Disposal and labels for PPE (gloves, protective eyewear, coveralls, Plastic Container Recycling respirators, etc.). Neurotoxic insecticides include organophosphates and carbamates, and the symp- Most pesticide products become classified toms of acute poisoning develop within minutes to hazardous waste upon disposal and fall under the hours after exposure. Most commonly reported ear- Washington State Dangerous Waste Regulations, ly symptoms include headache, nausea, dizziness, Chapter 173-303 WAC, which is administered sweating, salivation, tearing, and nasal discharge. by the Washington State Department of Ecology. Muscle twitching, weakness, tremor, incoordina- The regulations are complex. A grower who needs tion, vomiting, abdominal cramps and diarrhea to dispose of pesticide formulations or excess signal more severe poisoning. tank mix should contact the appropriate regional Ecology office for guidance. Northwest Regional Office (Bellevue): Protections, Emergency Treatment, and 425-649-7000 Pesticide Information Southwest Regional Office (Lacey): Good hygiene is important to reduce exposures. 360-407-6300 Wash your hands and face when done with a Central Regional Office (Yakima): task, and shower at the end of the day. Wear clean 509-575-2490 clothes and PPE each day. Wash contaminated Eastern Regional Office (Spokane): clothing separate from the family laundry. 509-329-3400 Call the National Poison Center at 1-800-222-1222 The Washington State Department of Agriculture’s for emergency information if an exposure occurs; Waste Pesticide Program collects and disposes of they are staffed 24-hours a day. The person answer- unusable pesticides owned by agricultural produc- ing your call will refer you to the nearest hospital ers. This program depends on state funding. Sev- handling pesticide poisonings. eral collections are held throughout the state each year. Contact 1-877-301-4555 or visit their web Emergency First Aid Basics—reference the pesticide site: http://agr.wa.gov/pestfert/pesticides/wastepes- label. ticide.aspx. l. Reduce the exposure immediately when it Triple-rinsed, plastic pesticide containers, large and occurs. small, are collected by the ACRC (Ag Container a. Remove contaminated clothing, wash the Recycling Program) contractor, which is currently affected area, then put on clean clothes. Agri-Plas in Oregon; http://agriplasinc.com. They provide collection and processing services for triple b. Move to fresh air when pesticides are in or pressure-rinsed plastic pesticide containers. They your air space. offer mobile grinding and whole container pickup, c. Rinse eye for 15 minutes if material and have a pickup schedule on their web site. enters the eye. 2. If breathing stops, the most important first Symptoms of Pesticide Poisoning aid is artificial respiration. Make sure first responders take care to avoid exposure while Herbicides and fungicides can result in skin, eye, performing first aid. or throat irritation. Redness or rashes are the most common poisoning systems. Some surfactants 3. Never try to give anything by mouth to an in herbicides are similar to soaps and can irritate unconscious person. or damage eyes. Read labels and wear noted PPE Lastly, another resource for getting answers to (gloves, protective eyewear, respirators, etc.) to pro- questions about safety issues related to pesticides tect skin and eyes, and prevent inhalation. is the National Pesticide Information Center, Many insecticides work on the human nervous sys- http://npic.orst.edu, or call 1.800.858.7378 tem the same way they do on insects; it’s the dose between 8:00 AM to 12:00 PM Pacific Time, that makes the poison. They can enter through Monday through Friday. You can always email eyes or skin or by ingestion or inhalation. Read them as well at npic@ace.orst.edu. 3
WEED CONTROL Weeds can directly compete with grapevines To reduce the hazard of injury to vines as well for water, nutrients, and light. Weeds may also as to ensure the maximum effectiveness of the impact vines indirectly, by serving as alternate herbicides applied, select your equipment and its hosts for insect pests and pathogens; providing use carefully. Herbicides need to be applied with a habitat for rodents; altering the distribution of fixed boomtype applicator equipped with flat, fan- irrigation water; interfering with the deposition type nozzles. The height of the boom depends on of pesticides; and impeding the movement the height of weeds, the nozzles, and their spacing. of workers and equipment. Successful weed Take care to ensure a uniform spray pattern and, management can be achieved by employing a thereby, a uniform herbicide deposit. Similarly, combination of strategies, which includes the use the speed of travel must be closely regulated. It is of herbicides, to eliminate unwanted vegetation limited not only by safety, but also by the capacity from vineyards. Herbicides, however, act upon of the pump. Regulating the pressure does not suf- different weed species and in different ways; care ficiently alter the output. In general, use speeds of must be taken to ensure that the selected products around 1.5 to 2 miles per hour. will be effective at controlling the weed species that are present in the system. Herbicides are Use low pressures (20 to 35 psi) to ensure coverage also capable of causing serious injury or death of and penetration while minimizing spray drift. vines and/or may have significant unintended NOTE: With glyphosate, reduce the pressure to less consequences on neighboring ecosystems. than 20 pounds (psi). Consequently, applicators must ensure that an acceptable level of crop safety can be achieved Constant agitation of the spray mixture is essen- and that off-site/off-target damage is prevented. tial with wettable powders and dry flowables, and agitation must be vigorous when using oils. The most appropriate choice of herbicide (or com- A defoaming agent can be used. Follow quantity bination of herbicides) will be affected by numerous and directions on label. factors including: • how weed control will be achieved, General Precautions • the kind of weeds to be controlled, 1. Do not apply any herbicide to grapes • the size and/or age of the weeds to be unless there is a label registration for its controlled, use on grapes. • soil type and herbicide incorporation strategy, 2. Check all herbicide or other pesticide uses • the quantity and quality of the spray water, with the processor or field representative • the age and health of the vines. before using. 3. Do not use a combination of herbicides or other chemicals with herbicides unless the Application Rate and Equipment combination has been thoroughly tested and The rate or amount of herbicide to be applied is confirmed to not cause phytotoxic effects. shown as the amount per acre of the actual por- 4. Avoid herbicide application to any part of tion treated (i.e., the area directly under the vine the vine. Do not use weed sprayers to apply row, or the area between vineyard rows), and not other pesticides to vines. the total herbicide to be applied to an acre of vine- yard. Thus, a 10-foot row spacing with a 2-foot 5. Do not repeatedly use the same mode of band of herbicide sprayed under the vines would action (MOA) throughout the season (Table 1). be two-tenths (one-fifth) of an acre to be treated or Using different MOAs is part of a good 20% of one acre of vineyard. herbicide resistant management program. 4
Table 1. Mode of action of herbicides registered for use in grapes in the Pacific Northwest. Resistant Weed Herbicide Trade Name1 Chemical Name WSSA Group2 HRAC Code3 Species in PNW?4 Fusilade fluazifop 1 A Yes Poast sethoxydim 1 A Yes Select (and others) clethodim 1 A Yes Matrix (and others) rimsulfuron 2 B Yes Mission flazasulfuron 2 B Yes Kerb pronamide 3 K1 Yes Prowl (and others) pendimethalin 3 K1 Yes Surflan (and others) oryzalin 3 K1 Yes Treflan (and others) trifluralin 3 K1 Yes Princep (and others) simazine 5 C1 Yes Karmex (and others) diuron 7 C2 Yes Roundup (and others) glyphosate 9 G Yes Rely (and others) glufosinate 10 H Yes Solicam norflurazon 12 F1 No Aim carfentrazone-ethyl 14 E No Chateau flumioxazin 14 E No Goal (and others) oxyfluorfen 14 E No Venue pyraflufen-ethyl 14 E No Zeus XC sulfentrazone 14 E No Zeus Prime XC sulfentrazone + 14 E No carfentrazone-ethyl (both) (both) Devrinol napropamide 15 K3 Yes Casoron dichlobenil 20 L No Gallery (and others) isoxaben 21 L No Gramoxone (and others) paraquat 22 D No Alion indaziflam 29 L No 1 Herbicide Trade Names are for example purposes only and does not indicate an endorsement of a specific brand or company. Some active ingredients are available under multiple trade names. 2 WSSA = Weed Science Society of America 3 HRAC = Herbicide Resistance Action Committee 4 At least one weed species resistant to this mode of action documented to occur in ID, OR, or WA; data from Heap, I. The International Survey of Herbicide Resistant Weeds. Available at www.weedscience.org 5
Factors Affecting Control It is possible for weed communities in vineyards to be comprised of species that are naturally sensi- Classification of Herbicides tive to different herbicides or herbicide modes of action. They may also differ with respect to life his- Herbicides differ with respect to how they are used. tory traits or emergence patterns. Herbicide labels When describing herbicides, we can refer to them list the weed species that can be suppressed or as being either ‘pre-emergence’ or ‘post-emergence’ controlled by the active ingredient. The labels will applied. Pre-emergence herbicides are soil-applied also provide instructions on when to time applica- products that act primarily on germinating weed tions to maximize herbicide efficacy and will also seeds or young weed seedlings. They persist in the list appropriate tank-mix partners to help growers environment to provide extended weed control expand the spectrum of weed control. Always read within or across seasons. labels to ensure that herbicide applications will be both effective and safe. Products classified as post-emergence herbicides are applied directly to the foliage of emerged weeds For help on weed identification, visit: http://wine. to elicit control. Post-emergence herbicides can wsu.edu/researchextension/plant-health/weed- be further characterized as being either ‘contact’ management/. In addition, Washington State or ‘systemic’ products. Contact generally refers University Extension also provides a free Weed to herbicides that only affect the tissues that are Identification Service. Information on this service directly treated with the herbicide—these types of can be found at: http://css.wsu.edu/extension/ herbicides do not move (translocate) to untreated weed-identification/. parts of the plant following application. Systemic or translocated herbicides can move from treated The Size and/or Age of the Weed to be plant parts to untreated tissues via the xylem or Controlled phloem. Although some herbicides may exhibit both pre- and post-emergence activity, a combina- Weed control strategies may not always be 100% tion of both foliar and soil-applied products are effective and escapes can occur for numerous typically used to successfully manage weed com- reasons. One of those reasons is the size of plants munities in vineyards. at the time of application. The efficacy of post- emergence herbicides is often diminished when Often, herbicides are referred to as being either products are applied to large/mature plants. This ‘selective’ or ‘non-selective’ (which is synonymous can result from poor spray coverage and the abil- with ‘broad-spectrum’). A selective herbicide is one ity of dense foliage to shield sensitive tissue from that is effective at controlling some species but not herbicide deposition. While plant size is mainly others. Conversely, a non-selective herbicide is an a concern with contact herbicides, the efficacy herbicide that can control many different types of systemic products can also be influenced. For of weedy pests. The most well-known examples example, may perennial species are tolerant of of herbicide selectivity are 1) the abilities of the many herbicides, including translocated products ‘-fops’ and the ‘-dims’ (e.g. fluazifop and clethod- like glyphosate, because their root systems and im) to suppress grasses but not broadleaf species nutrient reserves support regeneration/regrowth. and 2) the control of broadleaved weeds, but not There are several strategies that growers can take grasses, by synthetic auxins (e.g. 2,4-D). to maximize weed control with post-emergence herbicides, including: timing applications to treat Kinds of Weeds to be Controlled weeds while they are small/tender, applying herbi- cides at appropriate rates and volumes, and using Weed species can be described by the length of label recommended adjuvants to improve herbicide their life cycle. Annual weeds (both winter-and contact and penetration. summer-germinating) emerge, grow, flower, and set seed all within the course of a year. Biennial weeds The development of herbicide resistance is a sig- complete their life cycles over the course of two nificant concern for growers of perennial crops, years whereas perennials can persist across multi- including grapes. Weed species with resistance to ple seasons. Not all herbicides are equally effective glyphosate, glufosinate, and paraquat have been against all three types of weed species. For exam- confirmed in California and Oregon as well as ple, although the seedlings of perennial weeds may other Western states. Incomplete weed control can be controlled by pre-emergence herbicides, much increase the chance of a herbicide resistant biotype like annual species, mature plants are unlikely to reaching reproductive maturity, setting seed, and be impacted. becoming established in a production system. Her- 6
bicide labels will provide instructions to applicators The Quantity and Quality of the Spray Water regarding strategies for resistance management. Additional information can be found at the Weed Water is the main carrier for crop protection Science Society of America’s (WSSA) web-page: products, including herbicides. Consequently, the http://wssa.net/wssa/weed/resistance/. quantity and quality of spray water can impact herbicide distribution and performance. In gen- eral, higher carrier volumes have been shown to Soil Type and Herbicide Incorporation Strategy improve the efficacy of foliar-applied herbicides The length of time that pre-emergence herbicides (glyphosate is a notable exception). Post-emer- may reside in a treated area will be influenced by gence herbicide labels provide instructions regard- multiple factors, such as soil texture and organic ing the recommended application parameters (i.e. matter content. Soils that are high in clay or GPA, pressure, droplet size) to maximize weed organic matter can bind herbicides tightly to the control potential. Carrier volume can also affect soil matrix. Conversely, coarse soils can enhance the delivery of soil-applied products; always read leaching potential. Herbicide persistence is also a the herbicide label to ensure that all herbicides are function of herbicide chemistry. Some herbicides used both effectively and safely. naturally bind very tightly to soil particles whereas others are significantly more mobile. The interac- Water quality factors can also affect herbicide per- tions between soil and herbicide chemistry can formance and safety. For example, herbicides that affect a product’s use rate within a given system. are weak acids (such as glyphosate) can have their This, in turn, may influence how well a herbicide efficacy reduced under alkaline conditions (pH >7). performs, as well as how long it remains in the Salts and soil particles in spray water can bind to treated zone. some herbicides, thereby affecting their dispersal, deposition, and uptake. Water quality recommen- To be effective, pre-emergence herbicides must dations exist for both pre- and post-emergence be incorporated (usually 1–2" deep) into the soil herbicides; read labels carefully. profile. Incorporation is required because these products are mostly active against newly germi- The Age and Health of the Vines nated weed seedlings. Additionally, incorporation is needed to reduce or prevent volatilization and Vine age can affect what herbicides are available photodegradation, which can result in reduced for use in a production system. While competi- herbicide performance. The length of time an tion from weeds is most severe in in newly planted herbicide can remain on the soil surface varies grapes, not all herbicides are labeled for use around dramatically among products. Even if an herbicide young canes. Growers should be aware of re-plants does not require immediate activation to prevent in mature vineyards before making soil-applied product loss, an unincorporated herbicide is unable treatments. Regardless of vine age, residual herbi- to control emerging weeds. While many growers cides should be applied to soil that is settled and will time herbicide applications to take advan- free of cracks to minimize the potential for crop tage of naturally occurring rainfall, uncoopera- injury. Avoid using herbicide-treated soil to backfill tive weather may require the use of irrigation for planting holes. Unless specifically noted on the activation. Some products, due to their mobility label, avoid herbicide spray or mist contact with and potential for crop injury, may be incompatible leaves, green bark, roots, or fruit to reduce the with sprinkler systems; this is of particular concern potential for crop injury. when grapes are grown on shallow, coarse, sandy, or gravelly soils. Crop safety is paramount; however, the safety of species and habitats outside of the treated area are Check pre-emergence herbicide labels carefully also a significant concern. Follow label instruc- to ensure that the product is being applied at tions to reduce the potential of spray or volatil- the proper time of year to effectively target the ity drift and subsequent damage to off-target weed species of concern in a vineyard. Apply and organisms. Surface and groundwater advisories incorporate products as described to prevent crop and buffer zone recommendations are included injury; this includes following timing recommen- on several herbicide labels; read and follow all dations to avoid treating vineyards when and if labeled guidelines to prevent contamination of significant crop damage could occur. aquatic systems. 7
General Precautions planting, preferably in the winter after transplant- ing. Casoron CS can be applied after vines are 12 1. Do not apply any herbicide to grapes unless months old. there is a label registration for its use on grapes. Diuron (Karmex DF, Diuron 4L) WSSA Group 7: 2. Check all herbicide or other pesticide uses with the processor or field representative photosystem II inhibitor before using. Diuron has pre-emergence and some post-emer- 3. Do not use a combination of herbicides or gence activity. Weeds should not be >2 inches in other chemicals with herbicides unless the height or diameter or else post-emergence control combination has been thoroughly tested and may be compromised. confirmed to not cause phytotoxic effects. Diuron should be applied during the rainy period 4. Avoid herbicide applications to any part of (from about November 1 to February 15 in eastern the vine. Do not use weed sprayers to apply Washington), but not to frozen ground. Spring other pesticides to vines. applications may not be as effective unless rains 5. Do not use the same mode of action (MOA), fall soon after application to incorporate the her- repeatedly, throughout the season. Using bicides; however, heavy rains following a spring different MOAs is part of a good herbicide application may result in plant injury. Application resistant management program. to vineyards under sprinkler irrigation can be haz- ardous. Apply as a banded application to vineyards that have been established for at least 3 years and Soil-applied Herbicides: that have vines >1.5 inches in diameter. Do not apply to vineyards with shallow, coarse, sandy, or Dichlobenil (Casoron CS, Casoron 4G) WSSA gravelly soils or to soils with less than 1% organic Group 20: inhibits cell wall synthesis matter. Serious herbicide injury to grape roots has occurred when this herbicide is applied under A soil-active herbicide for long-term or seasonal improper conditions. Do not apply more than 5 lbs control of most weeds. Dichlobenil can suppress of Karmex DF per acre in a single use; do not apply the growth of some perennials (Canada thistle, more than 10 lbs per acre per year. Do not apply quackgrass, field bindweed and bermudagrass), more than 4 qts of Diuron 4L per acre in a single although higher use rates are recommended. use; do not apply more than 8 qts per acre per year. Dichlobenil is most effective when applied in the fall, at the beginning of the rainy season (about Flazasulfuron (Mission) WSSA Group 2: November 1 to February 15 in eastern Washington) acetolactate synthase (ALS) inhibitor and when the ground is cool. Application before Mission is labeled for the control of certain broad- a rain will reduce volatility and improve weed leaf and grass weeds including annual ryegrass, suppression. Do not apply when the ground is common mallow, clover and willowherb. Mission frozen. Applications can be made in the spring up has both pre- and early post-emergence activity; to about May 1 (when the soil surface is still 60°F weeds should be
formulated product per acre per year (maximum of Alion is most effective when applied in the fall or 0.089 lbs of active ingredient or 5.7 oz of Mission early spring to dry soil surface that does not have per acre per year). The minimum allowed interval crack or depressions. Apply as a uniform broadcast between treatments is 3 months. Do not apply or banded application. Alion applications should within 75 days of harvest. A 25-foot buffer must be followed by 48 hours without irrigation or be maintained between the point of direct applica- rain; activating moisture (0.25 to 0.5 inches) must tion and the closest downwind edge of sensitive be received within 21 days or before weed seeds terrestrial habitats (forested areas, riparian areas), germinate. Do not use on sand or soils contain- freshwater habitats (lakes, rivers, sloughs), and ing >20% gravel. Alion should not be applied to estuarine/marine habitats. frozen or snow covered soils, or saturated soils. Use only on vines established at least three years Flumioxazin (Chateau SW) WSSA Group 14: that are exhibiting normal growth and good vigor. Ensure that there is 6 inches of soil between the protoporphyrinogen oxidase (PPO) inhibitor soil surface and the major portion of the root. Do Chateau has both pre- and early post-emergence not apply more than 5 fluid ounces of formulated activity and can control broadleaf weeds up to product (0.065 lbs of active ingredient) per acre per about 2 inches tall. If weed emergence is significant year; coarse soils with less than 1% organic matter or weeds are large, consider mixing flumioxazin require a lower use rate per application. If making with an approved post-emergence herbicide to more than one treatment per year, allow for 90 improve control. days between applications. Do not apply within 14 days of harvest. Clean spray tank thoroughly The preferred time for pre-emergence applications after use. Surface and groundwater advisories are is fall, in order to maximize the potential for rain included on the label because of potential to harm to activate the herbicide. Do not apply to vines nontarget aquatic organisms, and potential for established less than 2 years, unless they are trel- runoff and percolation to ground water. lised at least 3 ft from the ground, and protected by nonporous wraps, grow tubes, or waxed con- Isoxaben (Gallery DF, Trellis SC) WSSA Group tainers. Do not apply to non-trellised vines unless 21: cell wall synthesis inhibitor they are free-standing. New plantings of own-root- ed varieties should have root systems a minimum A pre-emergence applied herbicide for the control of 8 inches below the soil surface. Chateau should of many annual broadleaf weeds. not be applied to soils that are susceptible to dis- persal by wind; wind-blown, herbicide-treated soil Available for non-bearing (Gallery) and bearing can cause serious injury to grapes and other plants. (Trellis) vineyards, but do not apply to newly Do not apply after budbreak through final harvest transplanted vines until the soil has settled and is in juice and wine grapes, unless using shielded free of cracks. Do not apply Trellis within 165 days application equipment and applicator can ensure of harvest. Must be incorporated within 21 days spray drift will not come in contact with crop fruit and before weeds emerge. Activate with 0.5 inch of or foliage. Dust created by mowing can also injure water or shallow cultivation before weeds emerge. sensitive species; do not mow between budbreak Most effective when applied to soil that is debris and final harvest. The application and maximum free. For bearing vineyards, do not make more than use rates can vary with weed species and soil type, 2 applications per year up to a max use rate of 1 lb but will not exceed 12 oz of formulated product of active ingredient per acre per year. Select appli- per acre per application and 24 oz of formulated cation rates based on weeds present. product per acre per year. Do not apply within 60 days of harvest. Do not apply within 300 yards of Napropamide (Devrinol 2-XT, 50 DF) WSSA non-dormant pears. Group 15: inhibits very long chain fatty acid synthesis Indaziflam (Alion) WSSA Group 29: inhibits cellulose biosynthesis A pre-emergence herbicide for the control of some annual grasses and broadleaf weeds. Will not give Alion is labeled for the pre-emergence control of complete control of nightshade, flixweed, tansy many annual grasses and broadleaf weeds. Con- mustard, tumble mustard, or perennial weeds. trols perennial weeds from seed, only. The spec- trum of weeds controlled will be affected by rate Apply fall through spring before weeds germinate. and the timing of activation. May be applied to both newly planted and estab- 9
lished vineyards. Applications made from Novem- essary to activate this herbicide. If weeds begin to ber 1 to February 15 should be incorporated with emerge before herbicide incorporation, a shallow irrigation or shallow cultivation if rainfall does not cultivation (1 to 2 inches) will kill existing weeds occur within 2 weeks of treatment. Performance is and place the herbicide in the zone of weed seed reduced if excessive residue occurs on the soil sur- germination. Surflan rates vary between 2 and 6 qt face. Applications made during the spring should per acre per application depending on the desired be activated with sufficient water to wet the soil length of weed control; the maximum use rate is to a depth of 2 to 4 inches within 24 hours. Can 12 lbs of active ingredient per acre per year. The be used safely in sprinkler-irrigated vineyards. The interval required between repeat applications is pre-harvest interval is 35 for the DF formulation 2.5 months. and 70 days for 2-XT. Do not apply more than 4 lbs of active ingredient per acre per crop cycle. Oxyfluorfen (Goal 2XL, Galigan 2E, GoalTender) WSSA Group 14: proto- Norflurazon (Solicam DF) WSSA Group 12: porphyrinogen oxidase (PPO) inhibitor inhibits carotenoid biosynthesis Provides both pre-emergent and early post- A broad spectrum pre-emergence herbicide that emergent control of broadleaf weeds in dormant will control many annual broadleaf and grass grapes. It is most effective post-emergence when weeds found in vineyards. Solicam does not have the seedling weeds have less than four leaves. Post- any post-emergence weed control activity. emergence weed control can be improved by tank- mixing with appropriate partners and adjuvants. Solicam can be applied from fall to early spring before the weeds emerge to non-frozen soil. The Direct the spray toward the base of vines in late soil should be settled and firm at the time of winter or spring, avoiding direct plant contact; application and the surface must be free of soil apply to bare soil. Apply after harvest, but before clods, depressions, weeds and other plant residue. bud-swell in spring. The closer grapes are to bud Requires rain to activate. If no rainfall occurs swell at time of application, the greater the chance within 4 weeks after application, the product of crop injury. Do not apply to grapes established must be activated by sprinkler irrigation. Applica- less than 3 years unless they have been staked or tion to vineyards under sprinkler irrigation may trellised 3 feet above the ground. Do not apply be hazardous to vines growing on coarse soils; do to grapes that are not staked or trellised unless not use on wine grapes grown in gravelly, sandy, they are free-standing. Apply only to healthy loamy sand, or sandy loam soils in Washington. vines. Overhead moisture within 3 to 4 weeks will Norflurazon should not be applied to vines estab- enhance herbicidal activity. The maximum use rate lished less than 2 years. Whitening may occur if is 2.0 pounds active ingredient per acre per season. norflurazon is applied within 3 months after bud The lower rate is for control of susceptible broadleaf break. The maximum use rate per year for grapes seedling weeds; the higher rate should be used for should not exceed 5 lbs of formulated product larger weeds or for preemergence control. per acre per year. Do not apply within 60 days of harvest. Pendimethalin (Prowl H2O, Prowl 3.3 EC) WSSA Group 3: microtubule assembly Oryzalin (Surflan AS, other tradenames) WSSA inhibitor Group 3: microtubule assembly inhibitor Prowl H2O and Prowl 3.3 EC are pre-emergence Surflan is a pre-emergence herbicide that is par- herbicides that are particularly effective against ticularly effective against annual grasses and some grasses. broadleaved weed species but will not give com- plete control of nightshade, tansy mustard, or Apply directly to the ground in dormant grapes tumble mustard. before bud-break and before weeds emerge. Overhead moisture is required within 7 days Can be used in newly planted (if the soil has for herbicide activation. Do not apply to newly settled around vines) and established vineyards. transplanted vines until the soil has settled and no Apply in late fall or early spring. Safe to use under cracks are present. If applying before transplanting, sprinkler irrigation. Treated areas must be free of do not allow treated soil to come into contact established weeds and well worked prior to spray with roots. Do not apply during or after bud swell application. A half-inch of rain or irrigation is nec- in the spring. Do not apply over the tops of vines 10
with leaves or open buds. Both labels include Simazine (Princep 4L, Princep Caliber) WSSA specific instructions regarding pre-plant or surface Group 5: photosystem II inhibitor incorporated, surface-applied, and pre-emergence applications. The use rate is determined by the Princep is a soil applied herbicide with efficacy weeds requiring control and the length of control against some grasses and broadleaf wed species. needed. The pre-harvest interval for Prowl H2O is 90 days. Prowl 3.3 EC is not labeled for use in Apply during the rainy period (from about Novem- bearing vineyards. ber 1 to February 15 in eastern Washington) as a single application. Do not apply to frozen ground. Requires surface moisture for activation. Do not Pronamide (Kerb 50-W, Kerb SC) WSSA apply to vineyards established less than 3 years or Group 3: microtubule assembly inhibitor to vineyards with shallow, coarse, sandy, or gravel- ly soils. Serious herbicide injury to grape roots has Pronamide is a soil-applied product that is used for occurred when applied under improper conditions. the control of grasses (annuals and some peren- Application to vineyards under sprinkler irriga- nials) and some broadleaved species primarily for tion is hazardous. Do not apply more than 4 lbs pre-emergence although Kerb can control some of simazine (active ingredient) per acre per year. small weeds that have emerged. Apply only once in the fall or early winter as a Sulfentrazone (Zeus XC, Zeus Prime XC) directed application when the soil temperature WSSA Group 14: protoporphyrinogen oxidase is below 55°F, but not when soil is frozen. Kerb is (PPO) inhibitor most effective when applied prior to weed emer- gence, to soil that is relatively free of residue, and A pre-emergence or early post-emergence herbicide when the application is followed by rainfall or for controlling several species of annual broadleaf weeds. If weeds are emerged, mix sulfentrazone irrigation. Use rate will be determined by the weed with an approved post-emergence herbicide. species to be controlled and soil type although the maximum use rate per acre per year is 4 lbs of Apply as a uniform broadcast soil application to active ingredient. Do not use on vines less than vineyard floors or as a uniform band directed at 1 year old, on fall-transplanted stock that has been the base of the vines then incorporate into the soil transplanted less than 1 year, or to spring-trans- with rainfall or irrigation. Trunks can be wrapped planted stock that has been transplanted less than in non-porous wraps, grow tubes, or wax container 6 months. Pronamide is a restricted-use chemical. to protect against spray contact. Do not apply to vines younger than 3 years old. Activity of sulfen- Rimsulfuron (Matrix FNV, Matrix SG) WSSA trazone increases dramatically under alkaline soil Group 2: acetolactate synthase (ALS) inhibitor conditions or when irrigated with alkaline water. The pH of the spray solution should be between 5 Matrix has both pre-emergence and very early and 9. If applied after bloom, use a shielded sprayer post-emergence activity. When weeds are present at to avoid movement of spray mist to flowers. application, include a labeled burndown herbicide. Sulfentrazone should not be applied to soils that are susceptible to dispersal by wind. Do not apply Can be applied broadcast to vineyard floor or to frozen soils. Do not apply more than 12 oz of banded at the base of the vines. Best pre-emergence Zeus XC per broadcast acre per 12-month period. results are obtained when the soil is debris-free and A prepackaged mix with carfentrazone-ethyl (Zeus moist at time of application, and the site receives Prime XC) is also available for grapes established 0.5 inches of rain or irrigation moisture within 2 at least 2 years. Do not apply more than 15.2 fluid weeks of application. Crops must be established for ounces of Zeus Prime per acre per year. Do not 1 year before application (vines should be healthy apply within 3 days of harvest. and growing vigorously). Susceptible weeds are controlled from 60 to 90 days after application. Trifluralin (Treflan 4D, Treflan 4EC, Treflan Two applications separated by 30 days are allowed HFP) WSSA Group 3: microtubule assembly if applied in bands that cover half of the vineyard. inhibitor Do not exceed 4 ounces of formulated product per acre on a broadcast basis per year. For best results, A soil-applied product that is used for the control maintain spray tank solution at pH 5 to 7. The pre- of grasses (annuals and some perennials) and many harvest interval is 14 days. broadleaved species. 11
Can be used prior to transplanting as well as estab- Fluazifop and sethoxydim are registered for use in lished vineyards. Apply before times of expected nonbearing and bearing vineyards; clethodim is weed emergence or immediately after existing registered for use only in nonbearing vineyards that weeds are controlled. Trifluralin is best applied in will not be harvested within 1 year after treatment. the spring to provide almost season-long control They are foliage applied, translocated herbicides of weeds. Must be mechanically incorporated 1 to which will control most actively growing grass 2 inches deep within 24 hrs following application weeds. The herbicide will not control annual blue- to be effective and prevent loss of activity. Mixing grass or the fine-leaf fescues. Results can be erratic activities should be done by equipment that will on grasses stressed from lack of vigor, drought, high not injure vine roots. Since trifluralin (Treflan) is temperature, or low fertility. Apply fluazifop to not leached into the soil, it is best applied in the actively growing grasses as a directed spray in water. spring and can be used in vineyards with sandy Add 1 quart crop oil concentrate or 0.5 pint nonion- soils or sprinkler irrigation. Use lower rates on ic surfactant to 25 gallons of spray material. Apply sandy soils or soil containing low organic mat- when susceptible grasses are in the labeled growth ter levels. Lower rates should also be used in areas stage. Apply clethodim to actively growing grasses receiving less than 20 inches rainfall and irrigation. as a directed spray in water. Add 1 pint of nonionic See label about mist propagated vines. The pre- surfactant to 50 gallons of spray material. Apply harvest interval is 60 days. sethoxydim to actively growing grasses listed on the label at the 4- to 5-leaf stage (6 to 12 inches tall). Add 2 pints of a non-phytotoxic oil concentrate per Foliar-applied Herbicides: acre. Do not apply to grasses which are stressed. Carfentrazone-ethyl (Aim EC) WSSA Group 14: protoporphyrinogen oxidase (PPO) inhibitor Glufosinate (Rely 280) WSSA Group 10: glutamine synthase inhibitor A contact herbicide that is active on annual broad- leaf weeds. Foliage applied, contact herbicide used to control annual broadleaf and grass weeds and to suppress Carfentrazone-ethyl may be applied alone or as perennial weeds. a tank mixture with other labeled herbicides as a post-emergence directed treatment or as a hooded Apply when weeds are small and actively growing. spray between rows to control emerged and Use as a directed spray. Avoid contact of spray or actively growing weeds. Good spray coverage of mist on new foliage or green shoots as severe vine the weeds is essential for control. May be applied injury may result. Use directed spray and shield anytime during the season. Control is enhanced young vines. Thorough coverage of target weeds with the addition of a nonionic surfactant or is essential for control. No additional surfactant is crop oil concentrate. Care must be taken not to needed. May be tank mixed with labeled residual allow spray mist to contact desirable fruit, foliage herbicides to control later germinating weeds. or green stem tissue. Lower rates may be used to Apply in a minimum of 20 gallons of water per control small susceptible broadleaf seedling weeds acre. Do not exceed 4.5 lb ai/acre per 12-month at the 2- to 3-leaf stage. The higher rate is needed season. Apply only to grapevines established at to control larger weeds up to the 6-leaf stage. Do least 1 year. Do not apply within 14 days of harvest. not use on newly-transplanted vineyards. Do not apply more than 2 oz of formulated product per Glyphosate (Roundup and other tradenames) acre per application. Do not apply more than WSSA Group 9: inhibits EPSP synthase 7.9 oz of formulated product per acre per season. Do not make sequential applications less than A translocated herbicide which controls many 14 days apart. The pre-harvest interval is 3 days. annual and perennial weeds, both grasses and broadleaves. Fluazifop (Fusilade DX), clethodim (Select and For optimum control of perennial weeds such as other tradenames) and sethoxydim (Poast) Canada thistle, field bindweed, and quackgrass, WSSA Group 1: acetyl CoA carboxylase consult labels for recommended rates and correct (ACCase) inhibitors timing in relation to weed growth. Adding sur- factant or mixing ammonium sulfate according Post-emergence control of annual and perennial to label may improve control of slightly stressed grasses. weeds. Apply in 20 to 60 gallons of water per acre 12
on emerged and actively growing weeds. Glypho- of water for thorough coverage of the weeds. Five sate does not provide residual weed control. If applications are allowed per year. This is a restrict- repeated treatments are necessary for weed con- ed-use herbicide. Do not ingest or inhale spray trol, do not exceed a total of 8 lbs ae per acre per mist. Wear protective clothing, face shields when year. Do not treat between 14 days before harvest mixing, and respirators during application. to fall dormancy when green foliage or shoots are in the spray zone. Follow all precautions on label. Pyraflufen-ethyl (Venue) WSSA Group 14: Repeated glyphosate applications have selected for protoporphyrinogen oxidase (PPO) inhibitor resistant biotypes of ryegrass, as well as other weed species, in the PNW. To avoid weed resistance, A contact herbicide that is active on annual broad- rotate and mix weed control practices. leaf weeds. Paraquat (Gramoxone SL 2.0, Firestorm) WSSA Apply when the weeds are less than 4 inches tall or 3 inches across. Use as a directed spray and Group 22: photosystem I electron diverter thoroughly cover weeds. Use lower rates for small Foliage applied, contact herbicide used to control weeds and higher rate for larger weeds. Avoid annual broadleaf and grass weeds and to suppress contact with desirable foliage, green bark, or fruit. perennial weeds. Use an approved agricultural buffering agent if using in water of equal to or greater than pH 7.5. Apply as a directed, shielded spray to the base of The addition of crop oil concentrate or nonionic vines when grasses and other weeds are growing surfactant is recommended for optimum control. actively and new growth is from 1 to 6 inches Tank mixing can increase the weed spectrum that high. With mustard-type annual weeds, apply is controlled. Mix only the amount of solution before leaves exceed 1 inch in diameter. Avoid that can be sprayed within 4 hours. Do not make contact of spray or mist on new foliage or green more than 3 applications or exceed 6.8 fluid shoots as severe vine injury may result. Add a non- ounces per acre per season. Allow at least 30 days ionic surfactant or crop oil concentrate according between applications. Shield 1 year old or younger to label; avoid anionic formulations that react in vines with non-porous wraps, grow tubes, or wax the tank to form insoluble precipitates. Paraquat is containers. Apply in a minimum of 20 gallons of corrosive to aluminum. Spray in 50 to 200 gallons water per acre. 13
HERBICIDE INJURY Herbicide Injury Northwest Vineyards (PNW 644) for pictorial guides to determining damage caused by various herbicides. Herbicide injury symptoms can sometimes be con- fused with injury resulting from viruses or deficien- Report incidences of injury or severe symptoms in cy of plant nutrients. 2,4-D, glyphosate, and some grapes from herbicide drift to the Washington State other classes of herbicides affect the new growth Department of Agriculture toll-free 1-877-301-4555. of grapevines, causing deformation of both shoots and leaves. The symptoms tend to disappear later in the season as the malformed foliage is covered 2,4-D Drift Documentation up by new growth. Serious crop damage can result if contamination occurs during the early portion To report damage in vineyards due to 2,4-D drift, of the growing season. Leaf symptoms of herbicide adequate documentation is necessary. Most docu- injury and other disorders can be found online at mentation must occur early in the spring, and WSU (http://wine.wsu.edu/extension/). See the weekly notes on plant development and the devel- Field Guide for Integrated Pest Management in Pacific opment of damage symptoms are also needed. 14
WEED MANAGEMENT PROGRAM FOR GRAPEVINES Broad categories of weeds and vineyard age are described for each herbicide. Detailed application notes are found in the previous sections on “Soil-applied” and “Foliar-applied” herbicides. It is important to reference those sections and the label before any application. MATERIAL PER ACRE TREATED* Rate of formulated Weeds to be Active ingredient product per application controlled and formulation per treated acre Vineyard age PRE-EMERGENCE WEED CONTROL Annual & some dichlobenil (a: Casoron 4G, a: 100–150 pounds Casoron 4G for vineyards which have been transplanted perennial weeds b: Casoron SC) more than 4 weeks; Casoron SC after vines have been b: 1.4–2.8 gallons transplanted for at least 12 months. Annual grasses & indaziflam (Alion) 3.5–5.0 fluid ounces Use only on vines established at least three years that are broadleaf weeds exhibiting normal growth and good vigor. Annual broadleaf isoxaben (a: Gallery DF, a: 0.66–1.0 pounds Gallery is labeled for non-bearing crops, only. Trellis is weeds b: Trellis SC) available for non-bearing and bearing vineyards, but do b: 20.3–31 fluid ounces not apply to newly transplanted vines until the soil has settled and is free of cracks. Annual grasses & napropamide a: 2 gallons For newly planted and established vineyards. broadleaf weeds (a: Devrinol 2-XT, b: Devrinol 50 DF) b: 8.0 pounds Annual grasses & norflurazon (Solicam DF) 1.25–5.0 pounds Norflurazon should not be applied to vines established broadleaf weeds less than 2 years. Annual grasses, some oryzalin (Surflan AS) 2.0–6.0 quarts Can be used in newly planted (if the soil has settled around broadleaf weeds vines) and established vineyards. Annual grasses, some pendimethalin a: 2.4–4.8 quarts Prowl 3.3 is labeled only for nonbearing vineyards; Prowl broadleaf weeds (a: Prowl 3.3 EC, H2O may be used in nonbearing or bearing vineyards. b: Prowl H2O) b: 3.2–6.3 quarts Do not apply to newly transplanted vines until the soil has settled and no cracks are present. Annual grasses, some pronamide a: 2.0–8.0 pounds Do not use on vines less than 1 year old, on fall- broadleaf weeds, (a: Kerb 50W, transplanted stock that has been transplanted less than some perennials b: Kerb SC) b: 2.5–9.5 pints 1 year, or to spring-transplanted stock that has been transplanted less than 6 months. Annual grasses & simazine a: 2.0 quarts For vineyards established at least 3 years. broadleaf weeds (a: Princep 4L, b: Princep Caliber 90) b: 2.2 pounds Annual grasses, some trifluralin (a: Treflan 4D, a, b, c: 2.0-4.0 pints For newly planted and established vineyards. For newly broadleaf weeds b: Treflan 4 EC, c: Treflan HFP) planted vineyards, follow rate on label based on soil type. PRE-EMERGENCE AND EARLY POST-EMERGENCE WEED CONTROL Annual grasses & diuron (Diuron 4L) E WA 0.8-2.4 quarts For vineyards established at least 3 years. broadleaf weeds W WA 1.6–2.4 quarts Annual grasses & flazasulfuron (Mission) 2.14–2.85 ounces For vineyards established at least 3 years; nonporous broadleaf weeds wraps, grow tubes, waxed containers, or other protective sleeves are required for vines in their 3rd season of growth. Annual broadleaf flumioxazin (Chateau) 6.0–12.0 ounces For vineyards established at least 2 years. weeds *Rates as given are per acre of ground sprayed. For band or spot treatment, calculate rates according to the actual portion of an acre treated. 15
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