Pest Management Guide for Grapes in Washington - 2019 WASHINGTON STATE UNIVERSITY EXTENSION EB0762 - Computing ...

Page created by Cathy Chen
 
CONTINUE READING
Pest Management Guide for Grapes in Washington - 2019 WASHINGTON STATE UNIVERSITY EXTENSION EB0762 - Computing ...
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
Pest Management Guide for Grapes in Washington - 2019 WASHINGTON STATE UNIVERSITY EXTENSION EB0762 - Computing ...
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
Pest Management Guide for Grapes in Washington - 2019 WASHINGTON STATE UNIVERSITY EXTENSION EB0762 - Computing ...
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
You can also read