General Considerations


Weed Identification:

As with insects and plant disorders, it is important to correct identify a suspected weed or unfamiliar plant before taking any control action. Along with a correct identification is gaining an awareness of the seasonal development and dispersal of the plant in order to correctly time the application of available chemical and non-chemical control options. 

There are several useful published weed field guides and Internet sites that should be consulted if there is any doubt as to the identity of the plant and its regulatory status (i.e. a noxious plant). Any plant not found in any of the publications or weed ID web sites should be delivered to the nearest BC Ministry of Agriculture or Canadian Food Inspection Agency office for further analysis by specialists to confirm if the plant is a new invasive plant species.

Picture Guides

Identification Keys 

  • Weedinfo.ca - a searchable database containing 139 weeds along with information on weed management research and related topics.

  • Weed Identification Keys - Ontario Crop IPM - follow the images of plant parts to identify an unknown plant 

Benefits of Weed Control:

The control of all vegetation around newly planted fruit trees is essential to promote satisfactory growth.  Recently planted trees compete poorly for moisture and nutrients even with sparse weed growth; heavy sods will cause severe stress resulting in the stunting of trees.  Reduction of competition from weeds continues to be very important in the life of the orchard, especially during the early part of the growing season.  Some re-growth after July 15 may be desirable to help the trees develop winter hardiness and to provide some ground cover and increase soil temperatures in winter.  The area around the tree trunks, however, should be kept relatively clean of vegetation to reduce the activity of voles and prevent them from girdling the trees.

 

Non-Chemical Weed Control:

Tillage - Hand weeding is practical only in very small areas.  Mechanical in-the-row tillage with self-guiding implements is generally only used in Organic management systems.  Mechanical weed control should be shallow enough not to harm tree roots and should not be done on steep slopes in order to avoid soil erosion.  It is more effective if the area is free of rhizome-forming weeds. 

 

Mulches - Weeds may also be controlled by the use of mulches.  Materials for mulches can be varied and adjusted to what is available and economical.  Sawdust or wood shavings can be used as long as certain species of trees are avoided (e.g. cedar).  Nitrogen nutrition will be more difficult to adjust when the mulch begins to decay.  Grass clippings, weed-free straw or hay can be used.  Plastic, polyethylene or polypropylene, especially the very durable woven materials, have been found to be very useful.  These mulches offer excellent weed control, as well as conserve soil moisture and provide increased spring soil temperatures.  The greatest benefit of plastic mulches may be derived from the crop never having any competition from weeds.  The main disadvantages to these mulches are their high cost, difficulty of installation, and increased vole habitat.

 

Chemical Weed Control:

There are many herbicides available to growers for chemical weed control.  Their use and characteristics are described in the next sections of this chapter.  Some tank mixes are registered and printed on the product label.  In the absence of specific label directions, herbicides may be mixed in the tank provided the individual chemicals are registered on the crop and the user assumes the risk and responsibility with respect to safety, efficacy and phytotoxicity. 

It is good practice to keep adjusting your weed control program for the following reasons; rotating between chemical groups will reduce the risk of weed resistance to specific herbicides; since no herbicide will control all weed species, repeat use of one program will select for the weed species naturally not controlled; repeat use of the same residual herbicide can lead to accumulation in the soil and possible phytotoxic effects.

In order not to over-apply herbicides (especially residual herbicides) use a calibrated sprayer.  Remember that the application rates refer to the area covered by the herbicide strip only, not to the whole orchard floor.

 

Pre-plant Site Preparation:

New fruit tree plantings can suffer severe competition from difficult to control perennial weeds such as quack grass, mountain brome grass, field bindweed, perennial vetch, etc., and their eradication should be attempted the year before planting.  High rates of glyphosate are suggested, followed by thorough tillage 7 to 10 days later.  For best results, adjust timing of application to the most susceptible stage of the weed (see label instructions).  In sites with mainly perennial grasses, a fall application of glyphosate may be used.  If field horsetail is a problem, other chemicals (amitrole) and cultural methods should be used.

 

Weed Control in Home Nurseries:

Site Preparation – Perennial weeds should be controlled the year before planting, the same as for new plantings (above).

Tillage – Between-the-row shallow tillage with in-the-row hand weeding is often the method of choice because it is simple.  To be effective it must be done regularly and without delay as even small weeds can cause significant growth reduction.  Care must also be taken when using tools to avoid root damage.

Mulch – Plastic mulch materials widely used in vegetable production have been used very successfully in combination with fertigation through bi-wall tubes or T-tape.  Plastic mulches generally produce higher quality trees than other weed control systems due to complete, safe weed control, and warmer soil temperatures.  Voles under the plastic must be controlled in the winter to prevent girdling of the trees.

 

Herbicide Resistance:

Resistance Prevention- Herbicide resistance results from a change in a weed population over time after repeated application of the same group of herbicides.  The best way to prevent herbicide resistance is to rotate herbicide usage so that the same herbicide group is not used year after year.  It is also beneficial to incorporate non-chemical methods of weed control.  Tank mixes of herbicides from different groups may also delay resistance. 

Identifying Resistant Weeds- Resistant weeds do not look different.  Before assuming that weeds surviving a herbicide application are resistant, rule out other factors that might have affected herbicide performance.  Check rates used, weather conditions and timing. If resistance appears to be likely check for the following:

  1. Are other weeds listed on the product label controlled satisfactorily?  Usually, only one weed species will show herbicide resistance in any given field. 

  2. Did the same herbicide or herbicides from the same group fail in the same area of the field in previous years?

  3. Do your records show extensive use of the same herbicide or herbicides from the same group year after year?

If one or more of these situations apply, it is possible that the weeds are resistant to the herbicide.  If resistance is suspected, control the weeds with a registered herbicide from another group or use appropriate non-chemical weed-control to prevent the weeds from going to seed.  Next, contact your field person, herbicide supplier or the appropriate chemical company to develop a weed-control program to manage the problem.

 

Control of Wild Fruit Trees:

To control weedy deciduous woody species such as wild apples and cherries carry out spot treatments with one of the following: (1) 2,4-D amine formulation at 0.3 -0.6 kg a.i./100L (1.4-2.7 kg a.i./ 100 gal) when leaves have fully expanded; (2) Dycleer (dicamba) + 2,4-D (1:2) when leaves have fully expanded; (3) glyphosate at 1.0-1.2 L/100L (4.5-5.5L/100 gal) in June – August.  When brush is less than 2 m high, the treatment can be made by spraying the stems and foliage to thoroughly wet.  Care should be taken to avoid chemical drift into crop areas.  If trees to be controlled are large, or too close to orchards, it may be preferable to score trunks and direct materials into the wounds.

 

Herbicides

Trade Name(s):  2,4-D Amine 600

Common Name:  2,4-D

Group:  4

Registered On:  Bearing apples, peaches, pears, plums, apricots, cherries

Target Weeds:  Most broadleaf weeds and brush

Activity:  Readily absorbed through leaves or roots.  Translocated primarily in phloem with the sugars but can also move with water in the xylem.  The amine formulations are registered but can still be volatile under some conditions.  Ester formulations are very volatile and therefore not registered on tree fruits.  Short residual life.

Use Suggestions:  Can be used at low rates in combination with glyphosate for broader weed control and prevention of resistance to glyphosate.

Application:  Post-emergence.  All weeds are more easily killed when growing rapidly in moist soil.  To prevent run-off do not irrigate within 24 hours of application.  Rainfast in 4 hours.  Take care to avoid spray drift or vapor drift coming in contact with grapes.  Even trace amounts of 2,4-D can cause damage to grapes and some other ornamental plants.

Re-entry Interval:  When product is dry

Days to Harvest:  80

Nurseries & New Plantings:  Not recommended

 

Trade Name(s):  Aim EC

Common Name:  carfentrazone-ethyl

Group:  14

Registered On:  Pome Group (Apple, Pear), and Stone Group (Apricot, Peaches, Nectarines, Prunes, Plums)

Target Weeds:  Very young broadleaf weeds

Activity:  Contact herbicide, not translocated in plant.  No residual activity.  Non mobile in soil.

Use Suggestions:  Alternative to Basagran when rotating herbicides.

Application:  Post emergence to actively growing weeds.  Less activity under dry conditions (drought or low humidity).  Always add an adjuvant (e.g. Agral 90). 

Re-entry Interval:  Not specified on label

Days to Harvest:  3

Nurseries & New Plantings:  Safe on crop 

 

Trade Name(s):  Alion

Common Name:  indaziflam

Group:  29

Registered On:  Pome Group (Apple, Pear), and Stone Group (Apricot, Sweet/sour Cherries, Peaches, Nectarines, Plums)

Target Weeds:  Annual grass and broadleaf weeds (see label)

Activity:   Weed seeds and seedlings must come into contact with the herbicide prior to emergence to be controlled.

Use Suggestions:  See label for instructions on mixing with other herbicides.

Application:  Apply to soils before weeds germinate.  Alion is most effective when adequate moisture is present and the application is followed by rain or an irrigation prior to weed germination.  Alion may be applied only once at any time throughout the growing season when the ground is not frozen or covered with snow. Avoid disturbing treated soil after application.

Do not to plant into Alion-treated soil for 2 years after treatment.

Re-entry Interval:  12 h

Days to Harvest:  14

Nurseries & New Plantings: DO NOT apply Alion to trees that have been established for less than three full growing seasons after transplanting.

 

Trade Name(s):  Assure II

Common Name:  Quizalofop-p-ethyl

Group: 1

Registered On:  All Stone fruit and Pome fruit

Target Weeds: annual grass weeds and quack grass

Activity:  Readily absorbed through leaves

Application:  Post-emergence.  For the control of grassy weeds listed on the label, apply ASSURE ® II Herbicide as a single post-emergent broadcast spray directed at the ground, at a rate of 0.38L/ha to 0.75L/ha with a recommended surfactant at 5 litres per 1000 liters of spray (0.5% v/v). See “Mixing instructions” section of the Assure ® II Herbicide label. Use ground application only. Use a directed spray application to minimize the amount of spray coming into contact with the fruit trees. Use a minimum of 100 litres of water/ha.

Re-entry Interval:  12 hours

Days to Harvest:  Do not apply within 14 days of harvest for Crop Group 11-09 (pome fruit) and Crop Group 12-09 (stone fruit)

 

Trade Name(s):  Authority 480

Common Name:  sulfentrazone

Group:  14

Registered On:  Apple

Target Weeds:  Annual grass and broadleaf weeds (see label).

Activity:   Weed seeds and seedlings must come into contact with the herbicide prior to emergence to be controlled.

Use Suggestions:  See label for instructions on mixing with other herbicides.

Application:  Apply to soils before weeds germinate.  Authority 480 requires rain or irrigation to activate. Do not tank mix with Chateau® or other products containing sulfentrazone.

Re-entry Interval:  12 h

Days to Harvest:  14

Nurseries & New Plantings: DO NOT apply Authority to trees that have been established for less than one full growing seasons after transplanting.

 

Trade Name(s):  Basagran

Common Name:  Bentazon

Group: 6

Registered On:  Newly planted apple, cherry, peach, pear, nectarine (directed applications)

Target Weeds:  Very young broadleaf weeds

Activity:  Mainly contact.  No translocation within the plant.  No residual activity.

Use Suggestions:  Safer in nurseries and new plantings than GRAMOXONE as it is less damaging to green bark.

Application:  Apply post emergence when weeds are small (less than 5 cm) and actively growing.  Use a surfactant.  Direct the spray away from crop foliage.  Rainfast in 6 to 8 hours.

Re-entry Interval:  12 hours

Days to Harvest:  Use on non-bearing trees only

Nurseries & New Plantings:  Direct spray away from crop foliage

 

Trade Name(s): BioLink® Herbicide EC

Common Name:  Caprylic Acid.. 47.16% Capric Acid.. 31.6%

 

Group: not specified

Registered On: Apples, Pears, Apricots, Cherries, Nectarines, Peaches, Plums

Target Weeds: grasses (such as annualryegrass, annual bluegrass, barnyard grass, large crabgrass and wild oat), sedges (such as yellow nutsedge), and broadleaf weeds (such as black mustard, black nightshade, cleavers, curled dock, redroot pigweed, velvetleaf, wild carrot, burning nettle, hairy nightshade, common purslane and narrowleaf plantain).

Activity:  BioLink® Herbicide EC provides control of annual and perennial broadleaf weeds and

grasses. BioLink® Herbicide EC works best on newly emerged, actively growing weeds that are less than 15 cm in height.

Application:  For grass and perennial weeds as well as more mature broadleaved weeds, use the higher application rates (6% to 9%) with up to 937 L of water per hectare, Repeat applications every 14-21 days as required to maintain the desired level of weed control

Re-entry Interval:  24 hours

Days to Harvest:  BioLink® Herbicide EC may be applied up to and including the day of harvest (preharvest interval (PHI) = 0 days).

 

Trade Name(s):  Casoron

Common Name:  dichlobenil

Group:  20

Registered On:  Apples, cherries, peaches, pears and plums.

Target Weeds:  Depending on the rate used, most weeds are susceptible to or suppressed by CASORON including perennials, vetch and horsetail.  Only fair control of poison ivy and Canada thistle.

Activity:  Inhibits cell growth at the growing points.  Volatilizes readily at temperatures over 10°C.  Mobile in soils with low organic matter.  Residual for 2 to 6 months.  Longer residual with higher rates and in higher organic matter soils.  Works well in combination with organic mulches.

Use Suggestions:  Consider using every few years as part of a rotation of herbicides.

Application:  Pre-emergence.  CASORON is a granular which must be spread uniformly for maximum efficacy.  Usually spread by hand or shaker.  Preferred application is in late fall before the soil freezes or the snow falls.  As temperatures approach 10°C or higher Casoron must be watered in during or immediately after application. 

Re-entry Interval:  12 hours

Days to Harvest:  Not specified on label, but normally applied late fall or early spring.

Nurseries & New Plantings:  Do not apply 3 months before or after planting grafted or budded rootstocks.  For finished trees wait 4 weeks after planting before applying Casoron and use lower rates on light soils.

 

Trade Name(s):  Chateau

Common Name:  flumioxazin

Group:  14

Registered On:  Bearing and non-bearing pome fruit group (apple & pear) and stone fruit group (apricot, cherry, nectarine, peach, plum, prune).

Target Weeds:  Selected grass & many broadleaf weeds.  Controls common groundsel.

Activity:  Does not leach or volatilize from soil, but does breakdown with microbial activity, therefore residual control decreases under conditions of higher microbial activity (increased temperature, moisture, high organic matter etc.).

Use Suggestions:  Alternative to simazine when rotating herbicides. 

Application:  Pre-emergence.  Check the label for soil type and rate combinations. Most effective when applied to bare weed-free soil.  Requires irrigation or rain to activate.  Slow to degrade when soils are cold, so can be applied in the late fall for spring control.  For apples, do not apply after budbreak unless using hooded or shielded application equipment and applicator can ensure spray drift will not come in contact with crop fruit or foliage.  Only apply to dormant pears.  All applications to pears, or within 100 metres of pears, must be made after final harvest in the fall or prior to 2 months before budbreak in the spring. 

Do not tank mix Chateau Herbicide WDG, or use in the same field, with Dual Magnum (metolachlor or s-metolachlor) as crop injury may occur.

Re-entry Interval:  12 hours

Days to Harvest:  60

Nurseries & New Plantings:  Do not apply to trees established less than 1 year unless protected by non-porous wraps, grow tubes or waxed container.

 

Trade Name(s):  Devrinol

Common Name:  napropamide

Group:  15

Registered On: Established apples, pears and peaches and newly planted apples, apricots, cherries, peaches, pears and plums.

Target Weeds:  Best on annual grasses, some control of selected annual broadleaf weeds.  Poor on mustards and common groundsel.

Activity:  Absorbed through the roots of germinating weeds.  Translocates upward through seedling.  Residual for about 8 weeks.  Resists leaching and volatilization.  Degrades in UV light.

Use Suggestions:  Good weed control for nurseries and new plantings due to excellent crop safety.

Application:  Pre-emergence only.  Water in with 5 to 10 cm water if no rainfall occurs within 7 days of application in the spring or fall, or 2 days in the summer. 

Re-entry Interval:  12 hours

Days to Harvest:  Not stated on label, but usually applied in spring only

Nurseries & New Plantings:  Settle soil with irrigation before application to ensure increased crop safety

 

Trade Name(s):  Dual Magnum

Common Name:  S-metolachlor

Group:  15

Registered On:  Bearing and non-bearing apples, apricots, cherries, peaches, pears and plums.

Target Weeds:  Annual grasses and select annual broad-leafed weeds (pigweed, lambs-quarters).

Activity:  Absorbed by germinating grasses mainly through shoot just above seed.  Absorbed by germinating broadleaf weeds through shoots and stems.   Normally residual in soil for 10 to 14 weeks.

Use Suggestions:  Use in combination with broadleaf weed herbicide.  Use as an alternative to PROWL, particularly when pressure from annual grass is low.

Application:  Best applied before weed seeds germinate.  Rainfall or irrigation within 10 days of application is required for maximum activity.  Do not use on soils with less than 2% organic matter. 

Re-entry Interval:  12 hours – read label for exceptions

Days to Harvest:  Not stated on label, but normally only applied in spring

Nurseries & New Plantings:  Safety on nurseries not tested.  Safe on new plantings.

 

Trade Name(s):  Glyphosate, Credit, Glyfos, Laredo, Round-up Weathermax, Round-up Transorb, Round-up Ultra, Touchdown, Wrangler

Common Name:  glyphosate

Group: 9

Registered On:  Both bearing and non-bearing apples, apricots, cherries, peaches, pears and plums.

Target Weeds:  Controls annual and perennial weeds, both broadleaved and grasses.  Poor control on field horsetail and fair control on vetch.

Activity:  Absorbed through foliage and translocated throughout the plant.  Readily adsorbed to soil organic matter.  No residual activity.

Use Suggestions:  Currently the herbicide most at risk for developing weed species resistance due to over-use.  Reduce use of glyphosate by alternating or tank mixing with herbicides from other groups.

Application:  Apply post emergence to actively growing weeds.  Best activity on perennial weeds is usually at the bud to bloom stage of growth.  Quack grass is best treated in the spring or fall when it is actively growing with at least 3-4 new leaves on each emerged shoot.  Do not allow herbicide solution to contact green foliage or green bark of trees.  Not usually damaging to mature trees when sprayed on root suckers during the spring, but at other times of the year suckers must be removed before spraying.  Do not apply to fresh cut or wounded wood.  Best results when applied in low water volumes.  Even small amounts of soil or organic matter in spray water will reduce efficacy.  Depending on the product used glyphosate is rainfast 1 to 6 hours after application, check the label.

Re-entry Interval:  Not specified

Days to Harvest:  30

Nurseries & Newly Planted Trees:  Recommended as a pre-planting treatment.  Treat area to be planted, and till 7 to 10 days later to control perennial weeds.  Not recommended first year after planting unless extreme care is taken to keep spray solution from contacting any part of the young tree. 

Warning:  Due to risk of explosion - do not mix, store, or apply glyphosate products in galvanized steel or unlined steel (except stainless steel) tanks.

 

Trade Name(s):  Ignite 15 SN

Common Name:  glufosinate

Group:  10

Registered On:  Bearing apples and pears, apricots, cherries (sweet and sour), nectarines, peaches and plums.

Target Weeds:  Non-selective – affects all actively growing green plants; regrowth of perennial species may occur.

Activity:  Absorbed through foliage; minimal translocation.  No residual activity.

Use Suggestions:  Alternative to glyphosate if there is low pressure from difficult to control or established perennials weeds.  Ignite will knock back root suckers without harming tree.

Application:  Post emergence application.  Avoid contact with leaves or green bark of crop, but suckers do not need to be removed.  Thorough coverage of the plant tissue to be controlled is essential.  Activity is influenced by environmental factors; at cool temperatures, poor moisture and low humidity speed of action may be reduced.  Heavy dew at time of application may reduce control of certain weed species.  Rainfast in 4 hours.

Re-entry Interval:  Not specified on label

Days to Harvest:  40

Nurseries & New Plantings:  Not recommended

 

Trade Name(s):  Lontrel

Common Name:  clopyralid

Group:  4

Registered On:  Bearing and non-bearing apples (spot treatments for vetch)

Target Weeds:  Vetch and other legumes.  Will also control/suppress Canada thistle, groundsel and dandelion.

Activity:  Absorbed by foliage and translocated readily throughout the plant. 

Use Suggestions:  Spot treatment for vetch control.

Application:  Post emergence as a spot treatment for vetch.  Apply at the early flowering stage.  Rainfast in 4 hours.

Re-entry Interval:  Not specified on label

Days to Harvest:  30

Nurseries & New Plantings:  Not recommended.  Vetch should be controlled before planting.

 

Trade Name(s):  Poast Ultra

Common Name:  sethoxydim

Group:  1

Registered On:  Non-bearing apple, peach and plum; bearing apples and pears, apricots, cherries (sweet and sour), nectarines, peaches and plums.

Target Weeds:  Post-emergent control of grasses. Does not control sedges or broadleaf weeds.

Activity:  Contact and systemic control.  Uptake is mainly through the leaves. No residual activity. 

Use Suggestions:  Alternative to glyphosate to control annual grasses, wild oats, volunteer cereals and quackgrass.

Application:  Post emergence application. Merge Adjuvant (1% v/v in 100-200 L/water/ha) must be added to all applications of Poast Ultra liquid emulsifiable herbicide, including tank mixtures with broadleaf herbicides. For optimum control, apply when grasses are at 2-5 leaf stage with adequate soil moisture, light to moderate weed infestations levels and under moderate temperatures (15-28°C). 

Re-entry Interval:  12 h

Days to Harvest:  30

Nurseries & New Plantings:  Non-bearing apples, peaches and plums.

 

Trade Name(s):  Prowl H20

Common Name:  pendimethalin

Group:  3

Registered On:  Both bearing and non-bearing Apples, apricots, cherries and peaches.

Target Weeds:  Controls most annual grasses and selected annual broad-leafed weeds (controls pigweed, wild buckwheat, but is poor on common groundsel and only fair on mallow).

 Activity:  Weeds are controlled as they germinate.  Translocation is not significant and emerged weeds are not controlled.  Very low mobility in most soils.  Residual period of about 8 weeks.

Use Suggestions:  Use in combination with a broadleaf pre-emergence herbicide (Chateau, SINBAR, simazine).

 Application:  Apply before weed seed germination.  Most effective when applied to moist soil, or activated with a short irrigation cycle immediately after application.

Re-entry Interval:  24 hours

Days to Harvest:  Apply in spring only

Nurseries and Newly Planted Trees:  Safety on nurseries not tested.  Safe on new plantings.

 

Trade Name(s):  Sandea

Common Name:  halosulfuron

Group:  2

Registered On:  Bearing apples.

Target Weeds:  Controls certain broadleaf weeds and nut sedge.

Activity:  Absorbed through the roots, shoots and foliage, and translocated through the plant.  Pre-emergent residual activity extended with higher rates.

Use Suggestions:  For best results, post-emergent applications should be made to actively growing weeds at heights described on the label. Activating soil moisture is necessary for optimum pre-emergent weed control. Avoid application when temperatures exceed 30°C. Avoid contact with tree foliage and fruit with spray or drift.

Application:  Pre- and post-emergence application as a broadcast treatment to orchard floor on each side of the tree rows. Use a non-ionic surfactant with post-emergent applications. Avoid irrigation for 2-3 days after post-emergent application. Observe resistance management recommendations on the label.

Re-entry Interval:  Not specified on label

Days to Harvest:  14

Nurseries & New Plantings:  Not specified.

 

 

Trade Name(s):  Sencor

Common Name:  metribuzin

Group:  5

Registered On:  Established (bearing) and year of planting apple, apricot, peach, pear, plum, cherries. 

Target Weeds:  Certain annual grass and broadleaf weeds.

Activity:  Most uptake via the roots.  Translocated upwards in the xylem.  Residual for 6 to 8 weeks. 

Use Suggestion:  Mix with Sinbar for broad spectrum control of emerging weed seeds.

Application:  Pre-emergence (to early post emergence for some weeds).  Use at lower rates on most Okanagan soils.  Rotate products and use well calibrated sprayer to ensure crop safety.  Do not use on muck soils or gravel soils with less than 2% organic matter.  Can be applied when treatment area is wet with dew but it should not rain for 6 hours after application.

Re-entry Interval:  12 hours

Days to Harvest:  60

Nurseries & New Plantings:  Not recommended with Okanagan soils

 

Trade Name(s): Serene

Common Name:  Acetic Acid

Group: not specified

Registered On:  Apples more than 1 year after establishment

Target Weeds: Annual Weeds Controlled: Ragweed species, Chickweed, Lamb's-quarters, Black Medic, and seedling Canada fleabane.

Perennial Weeds Suppressed: Dandelion, Plantain species, Clover species, Wild Carrot, Toadflax, Quack Grass, Tufted Vetch, Hawkweed species, Curled Dock, Canada thistle, Kentucky Bluegrass and Sedges.

Activity:  Serene is a post emergent, foliar active, vegetation management product. It can also be used in and around perennial food crops. Serene is non-selective to green foliage and is non-residual in soil. Best results are achieved from spring and early summer applications to actively growing young weeds. Degree of control depends on several factors, including weed size and stage at application. Apply on a mostly sunny day with temperatures at or above 21° C (70° F). Small annual weeds may be completely controlled with a single application. Control of larger, more established weeds, not completely desiccated with one application, may be short-term and require retreatment. Weeds that are mature, dormant or hardened due to moisture stress tend to be more tolerant to herbicide treatment. Complete coverage of undesirable vegetation is necessary to achieve control. Only contacted vegetation will be affected. Seedling perennial weeds may be controlled with a single application; however, repeat application is required for control of regrowth of established perennial weeds. Rainfall within 1 hour of application will reduce degree of control.

Application:  when weeds are small (3-5 leaf) and actively growing; mix a spray solution consisting of 1 L of product for each 3 L of water. Ensure adequate mixing. Spray unwanted vegetation to the point of wetness. FOR CONTROL OF LARGER ANNUAL WEEDS AND TOP GROWTH REDUCTION (SUPPRESSION) OF PERENNIAL WEED GROWTH. Mix a spray solution consisting of 1 L of product for each 2.25 L of water. Use an application system, solution volume and adequate spray pressure to ensure complete coverage of unwanted vegetation. Best results with larger weeds will be achieved by spot treatment. Retreatment is required for regrowth of perennial weeds. Avoid direct or indirect spray contact to the foliage. Do not apply after budbreak unless using hooded or shielded application equipment and applicator can ensure spray drift will not come in contact with fruit or foliage.

Re-entry Interval:  Once product is dry

Days to Harvest:  not specified

Nurseries & New Plantings:  Not recommended

 

Trade Name(s):  Simazine 480, Simadex, Princep nine-T

Common Name:  simazine

Group:  5

Registered On:  Bearing and non-bearing apples and pear.

Target Weeds:  Most annual broad leaved weeds, many annual grasses, and perennials starting from seed.  Particularly good at controlling annual seeds in the mustard family.  At low rates grasses will be the first to come through.

Activity:  Absorbed by root of developing seed; little or no foliar absorption; translocated upwards in xylem.  Residual in soil for about 8 weeks.

Use Suggestions:  At risk for herbicide resistance.  Reduce use by rotating with flumioxazin (Chateau) or other broadleaf herbicide.

Application:  Apply before weed seeds germinate.  Needs moisture to be activated, so apply to moist soil or irrigate after application.  Do not use on sandy soil with less than 2% organic matter.  Simazine is persistent in the soil.  It should only be used once a year.  Over application can cause crop damage, particularly in light soils.

Days to Harvest:  Not stated on label.  Generally applied only in spring.

Nurseries & New Plantings:  Do not use in nurseries.  On newly planted trees soil should be allowed to settle by rain or irrigation before application.  Use lower rates on new plantings.

 

Trade Name(s):  Sinbar

Common Name:  terbacil

Group:  5

Registered On:  Apples and Peaches 3 years and older.  1st year apples, apricots, cherries, peaches, pears, plums.

Target Weeds:  Best on annuals and perennial grasses, also controls some perennial broadleaf weeds (Watson’s Willowherb).

Activity:  Uptake mainly through roots.  Residual action for about 5 weeks, but this is impacted by soil type and amount of organic matter.

Use Suggestions:  Pre-emergent herbicide for peaches.  On lighter soils, lower rates in combination with Prowl or Dual can provide good weed control and more crop safety.

Application:  Pre-emergence.  Moisture is required to activate the chemical within 2 weeks of application.  Do not apply on soils with less than 1% organic matter.  Safety margin narrow on coarse soils (calibrate sprayer). Safety margin greater with peach rootstocks than other rootstocks species.

Re-entry Interval:  12 hours

Days to Harvest:  Not on label, but usually only applied in early spring.

Nurseries & New Plantings:  Not for nurseries.  Use lower rates for 1st year trees.

 

Trade Name(s):  Venture L

Common Name:  fluazifop-P-butyl

Group: 1

Registered On:  Bearing and non-bearing apples, pears, cherries, peaches, plums.

Target Weeds:  Broad range of annual and perennial grasses.  Does not control bluegrass or fescue species or sedges.

Activity:  Absorbed primarily by leaves.  Translocated to roots and rhizomes.  No residual activity.

Use Suggestions:  Alternative to Prowl when rotating herbicides, except Venture is applied post-emergence.  Could be used in spring when Chateau applied with fall glyphosate.

Application:  Post emergence.  Timing is important to effectiveness.  Apply when grasses are actively growing and annual grasses are in the 2 to 5 leaf stage and quack grass in the 3 to 5 leaf stage.  Rainfast in 2 hours.

Re-entry Interval: Not specified on label

Days to Harvest:  None specified on label, but normally applied in the spring.

Nurseries & New Plantings:  Safe

Warning:  Experimental feeding studies in rats have demonstrated that the active ingredient can produce birth defects and other adverse effects in the developing fetus of rats.  Women capable of bearing children should be particularly careful when handling this product.